| Abies concolor | (Gordon) Lindl. ex Hildebr. | Pinaceae | 8 |
| Abies guatemalensis | Rehder | Pinaceae | 8 |
| Abies religiosa | (Kunth) Schltdl. & Cham. | Pinaceae | 8 |
| Abies vejarii | Martínez | Pinaceae | 8 |
| Abildgaardia ovata | (Burm.f.) Kral | Cyperaceae | 8 |
| Abronia angustifolia | Greene | Nyctaginaceae | 8 |
| Abronia carnea | Greene | Nyctaginaceae | 8 |
| Abronia fragrans | Nutt. ex Hook. | Nyctaginaceae | 8 |
| Abutilon abutiloides | (Jacq.) Garcke ex Hochr. | Malvaceae | 8 |
| Abutilon fruticosum | Guill. & Perr. | Malvaceae | 8 |
| Abutilon hypoleucum | A.Gray | Malvaceae | 8 |
| Abutilon incanum | (Link) Sweet | Malvaceae | 8 |
| Abutilon malacum | S.Watson | Malvaceae | 8 |
| Abutilon mollicomum | (Willd.) Sweet | Malvaceae | 8 |
| Abutilon palmeri | A.Gray | Malvaceae | 8 |
| Abutilon parvulum | A.Gray | Malvaceae | 8 |
| Abutilon reventum | S.Watson | Malvaceae | 8 |
| Abutilon trisulcatum | Urb. | Malvaceae | 8 |
| Abutilon viscosum | (L.) Dorr | Malvaceae | 8 |
| Abutilon wrightii | A.Gray | Malvaceae | 8 |
| Acaciella angustissima | (Mill.) Britton & Rose | Fabaceae | 8 |
| Acaena elongata | L. | Rosaceae | 8 |
| Acalypha alopecuroidea | Jacq. | Euphorbiaceae | 8 |
| Acalypha arvensis | Poepp. | Euphorbiaceae | 8 |
| Acalypha californica | Benth. | Euphorbiaceae | 8 |
| Acalypha cincta | Müll.Arg. | Euphorbiaceae | 8 |
| Acalypha diversifolia | Jacq. | Euphorbiaceae | 8 |
| Acalypha leptopoda | Müll.Arg. | Euphorbiaceae | 8 |
| Acalypha macrostachya | Jacq. | Euphorbiaceae | 8 |
| Acalypha mexicana | Müll.Arg. | Euphorbiaceae | 8 |
| Acalypha monostachya | Cav. | Euphorbiaceae | 8 |
| Acalypha neomexicana | Müll.Arg. | Euphorbiaceae | 8 |
| Acalypha persimilis | Müll.Arg. | Euphorbiaceae | 8 |
| Acalypha phleoides | Cav. | Euphorbiaceae | 8 |
| Acalypha poiretii | Spreng. | Euphorbiaceae | 8 |
| Acalypha radians | Torr. | Euphorbiaceae | 8 |
| Acanthocereus tetragonus | (L.) Hummelinck | Cactaceae | 8 |
| Acer glabrum | Torr. | Sapindaceae | 8 |
| Acer negundo | L. | Sapindaceae | 8 |
| Acer saccharum | Marshall | Sapindaceae | 8 |
| Achimenes antirrhina | (DC.) C.V.Morton | Gesneriaceae | 8 |
| Achimenes erecta | (Lam.) H.P.Fuchs | Gesneriaceae | 8 |
| Achimenes grandiflora | (Schiede) DC. | Gesneriaceae | 8 |
| Achimenes heterophylla | (Mart.) DC. | Gesneriaceae | 8 |
| Achimenes skinneri | Lindl. | Gesneriaceae | 8 |
| Achyronychia cooperi | A.Gray | Caryophyllaceae | 8 |
| Acleisanthes anisophylla | A.Gray | Nyctaginaceae | 8 |
| Acleisanthes chenopodioides | (A.Gray) R.A.Levin | Nyctaginaceae | 8 |
| Acleisanthes lanceolata | (Wooton) R.A.Levin | Nyctaginaceae | 8 |
| Acleisanthes longiflora | A.Gray | Nyctaginaceae | 8 |
| Acleisanthes obtusa | (Choisy) Standl. | Nyctaginaceae | 8 |
| Acmella radicans | (Jacq.) R.K.Jansen | Asteraceae | 8 |
| Acmella repens | Rich. ex Pers. | Asteraceae | 8 |
| Acmispon americanus | (Nutt.) Rydb. | Fabaceae | 8 |
| Acmispon neomexicanus | (Greene) Brouillet | Fabaceae | 8 |
| Acmispon oroboides | (Kunth) Brouillet | Fabaceae | 8 |
| Acmispon strigosus | (Nutt.) Brouillet | Fabaceae | 8 |
| Aconitum columbianum | Nutt. | Ranunculaceae | 8 |
| Acourtia moschata | (Lex.) DC. | Asteraceae | 8 |
| Acourtia nana | (A.Gray) Reveal & R.M.King | Asteraceae | 8 |
| Acourtia purpusii | (Brandegee) Reveal & R.M.King | Asteraceae | 8 |
| Acourtia runcinata | (D.Don) B.L.Turner | Asteraceae | 8 |
| Acourtia wislizeni | (A.Gray) Reveal & R.M.King | Asteraceae | 8 |
| Acourtia wrightii | (A.Gray) Reveal & R.M.King | Asteraceae | 8 |
| Acrostichum aureum | L. | Pteridaceae | 8 |
| Acrostichum danaeifolium | Langsd. & Fisch. | Pteridaceae | 8 |
| Adelia vaseyi | (J.M.Coult.) Pax & K.Hoffm. | Euphorbiaceae | 8 |
| Adenophyllum wrightii | A.Gray | Asteraceae | 8 |
| Adiantopsis radiata | (L.) Fée | Pteridaceae | 8 |
| Adiantum aleuticum | (Rupr.) C.A.Paris | Pteridaceae | 8 |
| Adiantum amplum | C.Presl | Pteridaceae | 8 |
| Adiantum andicola | Liebm. | Pteridaceae | 8 |
| Adiantum braunii | Mett. | Pteridaceae | 8 |
| Adiantum capillus-veneris | L. | Pteridaceae | 8 |
| Adiantum concinnum | Humb. & Bonpl. ex Willd. | Pteridaceae | 8 |
| Adiantum poiretii | Wikstr. | Pteridaceae | 8 |
| Adiantum pulverulentum | L. | Pteridaceae | 8 |
| Adiantum tenerum | Sw. | Pteridaceae | 8 |
| Adiantum trapeziforme | L. | Pteridaceae | 8 |
| Adiantum tricholepis | Fée | Pteridaceae | 8 |
| Adolphia infesta | (Kunth) Meisn. | Rhamnaceae | 8 |
| Aechmea bracteata | (Sw.) Griseb. | Bromeliaceae | 8 |
| Aechmea mexicana | Baker | Bromeliaceae | 8 |
| Aeschynomene americana | L. | Fabaceae | 8 |
| Aeschynomene indica | L. | Fabaceae | 8 |
| Aeschynomene villosa | Poir. | Fabaceae | 8 |
| Agalinis heterophylla | (Nutt.) Small ex Britton | Orobanchaceae | 8 |
| Agalinis strictifolia | (Benth.) Pennell | Orobanchaceae | 8 |
| Agastache mexicana | (Kunth) Lint & Epling | Lamiaceae | 8 |
| Agastache pallida | (Lindl.) Cory | Lamiaceae | 8 |
| Agastache pallidiflora | (A.Heller) Rydb. | Lamiaceae | 8 |
| Agave albomarginata | Gentry | Asparagaceae | 8 |
| Agave americana | L. | Asparagaceae | 8 |
| Agave angustifolia | Haw. | Asparagaceae | 8 |
| Agave asperrima | Jacobi | Asparagaceae | 8 |
| Agave brunnea | S.Watson | Asparagaceae | 8 |
| Agave bulliana | (Baker) Thiede & Eggli | Asparagaceae | 8 |
| Agave debilis | A.Berger | Asparagaceae | 8 |
| Agave durangensis | Gentry | Asparagaceae | 8 |
| Agave flexispina | Trel. | Asparagaceae | 8 |
| Agave gentryi | B.Ullrich | Asparagaceae | 8 |
| Agave guttata | Jacobi & C.D.Bouché | Asparagaceae | 8 |
| Agave havardiana | Trel. | Asparagaceae | 8 |
| Agave inaequidens | K.Koch | Asparagaceae | 8 |
| Agave lechuguilla | Torr. | Asparagaceae | 8 |
| Agave longiflora | (Rose) G.D.Rowley | Asparagaceae | 8 |
| Agave maculata | Regel | Asparagaceae | 8 |
| Agave mapisaga | Trel. | Asparagaceae | 8 |
| Agave mitis | Mart. | Asparagaceae | 8 |
| Agave montana | Villarreal | Asparagaceae | 8 |
| Agave neonelsonii | Thiede & Eggli | Asparagaceae | 8 |
| Agave palmeri | Engelm. | Asparagaceae | 8 |
| Agave parryi | Engelm. | Asparagaceae | 8 |
| Agave rosei | Thiede & Eggli | Asparagaceae | 8 |
| Agave salmiana | Otto ex Salm-Dyck | Asparagaceae | 8 |
| Agave schidigera | Lem. | Asparagaceae | 8 |
| Agave shrevei | Gentry | Asparagaceae | 8 |
| Agave univittata | Haw. | Asparagaceae | 8 |
| Agave variegata | Jacobi | Asparagaceae | 8 |
| Agave victoriae-reginae | T.Moore | Asparagaceae | 8 |
| Agave vilmoriniana | A.Berger | Asparagaceae | 8 |
| Agave virginica | L. | Asparagaceae | 8 |
| Agave xylonacantha | Salm-Dyck | Asparagaceae | 8 |
| Ageratina adenophora | (Spreng.) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina areolaris | (DC.) D.Gage ex B.L.Turner | Asteraceae | 8 |
| Ageratina glabrata | (Kunth) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina havanensis | (Kunth) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina herbacea | (A.Gray) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina ligustrina | (DC.) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina mairetiana | (DC.) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina paupercula | (A.Gray) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina petiolaris | (Moc. & Sessé ex DC.) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina pichinchensis | (Kunth) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina rothrockii | (A.Gray) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina tomentella | (Schrad.) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratina wrightii | (A.Gray) R.M.King & H.Rob. | Asteraceae | 8 |
| Ageratum conyzoides | L. | Asteraceae | 8 |
| Ageratum corymbosum | Zucc. ex Pers. | Asteraceae | 8 |
| Ageratum houstonianum | Mill. | Asteraceae | 8 |
| Agonandra racemosa | (DC.) Standl. | Opiliaceae | 8 |
| Agrimonia gryposepala | Wallr. | Rosaceae | 8 |
| Agrimonia striata | Michx. | Rosaceae | 8 |
| Agrostis hyemalis | (Walter) Britton, Sterns & Poggenb. | Poaceae | 8 |
| Agrostis perennans | (Walter) Tuck. | Poaceae | 8 |
| Agrostis scabra | Willd. | Poaceae | 8 |
| Aiouea montana | (Sw.) R.Rohde | Lauraceae | 8 |
| Alchemilla orbiculata | Ruiz & Pav. | Rosaceae | 8 |
| Alchemilla pectinata | Kunth | Rosaceae | 8 |
| Alchornea latifolia | Sw. | Euphorbiaceae | 8 |
| Aldama cordifolia | (A.Gray) E.E.Schill. & Panero | Asteraceae | 8 |
| Aldama dentata | La Llave | Asteraceae | 8 |
| Allenrolfea occidentalis | (S.Watson) Kuntze | Chenopodiaceae | 8 |
| Allionia choisyi | Standl. | Nyctaginaceae | 8 |
| Allionia incarnata | L. | Nyctaginaceae | 8 |
| Allium cernuum | Roth | Amaryllidaceae | 8 |
| Allium drummondii | Regel | Amaryllidaceae | 8 |
| Allium longifolium | (Kunth) Spreng. | Amaryllidaceae | 8 |
| Allium rhizomatum | Wooton & Standl. | Amaryllidaceae | 8 |
| Allium runyonii | Ownbey | Amaryllidaceae | 8 |
| Alloispermum integrifolium | (DC.) H.Rob. | Asteraceae | 8 |
| Allowissadula holosericea | (Scheele) D.M.Bates | Malvaceae | 8 |
| Alnus acuminata | Kunth | Betulaceae | 8 |
| Alnus jorullensis | Kunth | Betulaceae | 8 |
| Alnus oblongifolia | Torr. | Betulaceae | 8 |
| Alophia drummondii | (Graham) R.C.Foster | Iridaceae | 8 |
| Aloysia gratissima | (Gillies & Hook.) Tronc. | Verbenaceae | 8 |
| Aloysia macrostachya | (Torr.) Moldenke | Verbenaceae | 8 |
| Aloysia wrightii | A.Heller | Verbenaceae | 8 |
| Alsophila firma | (Baker) D.S.Conant | Cyatheaceae | 8 |
| Alternanthera brasiliana | (L.) Kuntze | Amaranthaceae | 8 |
| Alternanthera caracasana | Kunth | Amaranthaceae | 8 |
| Alternanthera paronychioides | A.St.-Hil. | Amaranthaceae | 8 |
| Alternanthera pungens | Kunth | Amaranthaceae | 8 |
| Alternanthera pycnantha | (Benth.) Standl. | Amaranthaceae | 8 |
| Alternanthera sessilis | (L.) DC. | Amaranthaceae | 8 |
| Alvaradoa amorphoides | Liebm. | Picramniaceae | 8 |
| Amaranthus albus | L. | Amaranthaceae | 8 |
| Amaranthus fimbriatus | (Torr.) Benth. ex S.Watson | Amaranthaceae | 8 |
| Amaranthus greggii | S.Watson | Amaranthaceae | 8 |
| Amaranthus hybridus | L. | Amaranthaceae | 8 |
| Amaranthus hypochondriacus | L. | Amaranthaceae | 8 |
| Amaranthus palmeri | S.Watson | Amaranthaceae | 8 |
| Amaranthus polygonoides | L. | Amaranthaceae | 8 |
| Amaranthus powellii | S.Watson | Amaranthaceae | 8 |
| Amaranthus retroflexus | L. | Amaranthaceae | 8 |
| Amaranthus spinosus | L. | Amaranthaceae | 8 |
| Amaranthus viridis | L. | Amaranthaceae | 8 |
| Amaranthus watsonii | Standl. | Amaranthaceae | 8 |
| Amblyolepis setigera | DC. | Asteraceae | 8 |
| Ambrosia acanthicarpa | Hook. | Asteraceae | 8 |
| Ambrosia ambrosioides | (Delpino) W.W.Payne | Asteraceae | 8 |
| Ambrosia camphorata | (Greene) W.W.Payne | Asteraceae | 8 |
| Ambrosia cheiranthifolia | A.Gray | Asteraceae | 8 |
| Ambrosia confertiflora | DC. | Asteraceae | 8 |
| Ambrosia cordifolia | (A.Gray) W.W.Payne | Asteraceae | 8 |
| Ambrosia psilostachya | DC. | Asteraceae | 8 |
| Ambrosia trifida | L. | Asteraceae | 8 |
| Amelanchier utahensis | Koehne | Rosaceae | 8 |
| Amicia zygomeris | DC. | Fabaceae | 8 |
| Ammannia auriculata | Willd. | Lythraceae | 8 |
| Ammannia coccinea | Rottb. | Lythraceae | 8 |
| Ammannia latifolia | L. | Lythraceae | 8 |
| Ammannia robusta | Heer & Regel | Lythraceae | 8 |
| Ammoselinum popei | Torr. & A.Gray | Apiaceae | 8 |
| Amorpha fruticosa | L. | Fabaceae | 8 |
| Amorpha roemeriana | Scheele | Fabaceae | 8 |
| Ampelocissus acapulcensis | (Kunth) Planch. | Vitaceae | 8 |
| Ampelopsis cordata | Michx. | Vitaceae | 8 |
| Amphilophium crucigerum | (L.) L.G.Lohmann | Bignoniaceae | 8 |
| Amphilophium paniculatum | (L.) Kunth | Bignoniaceae | 8 |
| Amphipterygium adstringens | (Schltdl.) Schiede ex Standl. | Anacardiaceae | 8 |
| Amphipterygium molle | (Hemsl.) Hemsl. & Rose ex Standl. | Anacardiaceae | 8 |
| Amsinckia menziesii | (Lehm.) A.Nelson & J.F.Macbr. | Boraginaceae | 8 |
| Amsonia longiflora | Torr. | Apocynaceae | 8 |
| Amsonia palmeri | A.Gray | Apocynaceae | 8 |
| Amsonia tomentosa | Torr. & Frém. | Apocynaceae | 8 |
| Amyris madrensis | S.Watson | Rutaceae | 8 |
| Amyris texana | P.Wilson | Rutaceae | 8 |
| Anacampseros coahuilensis | (S.Watson) Eggli & Nyffeler | Anacampserotaceae | 8 |
| Andira inermis | (W.Wright) Kunth ex DC. | Fabaceae | 8 |
| Andropogon bicornis | L. | Poaceae | 8 |
| Andropogon cirratus | Hack. | Poaceae | 8 |
| Andropogon virginicus | L. | Poaceae | 8 |
| Androsace septentrionalis | L. | Primulaceae | 8 |
| Anemia adiantifolia | (L.) Sw. | Anemiaceae | 8 |
| Anemia phyllitidis | (L.) Sw. | Anemiaceae | 8 |
| Anemia tomentosa | (Savigny) Sw. | Anemiaceae | 8 |
| Anemone berlandieri | Pritz. | Ranunculaceae | 8 |
| Anemone tuberosa | Rydb. | Ranunculaceae | 8 |
| Anemopsis californica | (Nutt.) Hook. & Arn. | Saururaceae | 8 |
| Angelonia angustifolia | Benth. | Plantaginaceae | 8 |
| Anisacanthus linearis | (S.H.Hagen) Henrickson & E.J.Lott | Acanthaceae | 8 |
| Anisacanthus quadrifidus | (Vahl) Nees | Acanthaceae | 8 |
| Anisacanthus thurberi | (Torr.) A.Gray | Acanthaceae | 8 |
| Annona glabra | L. | Annonaceae | 8 |
| Annona globiflora | Schltdl. | Annonaceae | 8 |
| Annona longiflora | S.Watson | Annonaceae | 8 |
| Annona reticulata | L. | Annonaceae | 8 |
| Annona squamosa | L. | Annonaceae | 8 |
| Anoda acerifolia | Cav. | Malvaceae | 8 |
| Anoda crenatiflora | Ortega | Malvaceae | 8 |
| Anoda cristata | (L.) Schltdl. | Malvaceae | 8 |
| Anoda lanceolata | Hook. & Arn. | Malvaceae | 8 |
| Anoda pentaschista | A.Gray | Malvaceae | 8 |
| Anogramma leptophylla | (L.) Link | Pteridaceae | 8 |
| Anredera vesicaria | (Lam.) C.F.Gaertn. | Basellaceae | 8 |
| Antennaria marginata | Greene | Asteraceae | 8 |
| Antennaria parvifolia | Nutt. | Asteraceae | 8 |
| Anthurium pentaphyllum | (Aubl.) G.Don | Araceae | 8 |
| Anticlea elegans | (Pursh) Rydb. | Melanthiaceae | 8 |
| Anticlea frigida | (Schltdl. & Cham.) Zomlefer & Judd | Melanthiaceae | 8 |
| Anticlea virescens | (Kunth) Rydb. | Melanthiaceae | 8 |
| Antigonon leptopus | Hook. & Arn. | Polygonaceae | 8 |
| Apeiba tibourbou | Aubl. | Malvaceae | 8 |
| Aphanostephus ramosissimus | DC. | Asteraceae | 8 |
| Aphelandra scabra | (Vahl) Sm. | Acanthaceae | 8 |
| Apocynum androsaemifolium | L. | Apocynaceae | 8 |
| Apocynum cannabinum | L. | Apocynaceae | 8 |
| Apodanthera aspera | Cogn. | Cucurbitaceae | 8 |
| Apodanthera undulata | A.Gray | Cucurbitaceae | 8 |
| Aquarius cordifolius | (L.) Christenh. & Byng | Alismataceae | 8 |
| Aquilegia canadensis | L. | Ranunculaceae | 8 |
| Aquilegia chrysantha | A.Gray | Ranunculaceae | 8 |
| Aquilegia elegantula | Greene | Ranunculaceae | 8 |
| Aquilegia formosa | Fisch. ex DC. | Ranunculaceae | 8 |
| Aquilegia longissima | A.Gray ex S.Watson | Ranunculaceae | 8 |
| Arachnothryx leucophylla | (Kunth) Planch. | Rubiaceae | 8 |
| Aralia bicrenata | Wooton & Standl. | Araliaceae | 8 |
| Aralia humilis | Cav. | Araliaceae | 8 |
| Arbutus arizonica | (A.Gray) Sarg. | Ericaceae | 8 |
| Arbutus bicolor | S.González, M.González & P.D.Sørensen | Ericaceae | 8 |
| Arbutus madrensis | S.González | Ericaceae | 8 |
| Arbutus occidentalis | McVaugh & Rosatti | Ericaceae | 8 |
| Arbutus tessellata | P.D.Sørensen | Ericaceae | 8 |
| Arbutus xalapensis | Kunth | Ericaceae | 8 |
| Arceuthobium douglasii | Engelm. | Santalaceae | 8 |
| Arceuthobium globosum | Hawksw. & Wiens | Santalaceae | 8 |
| Arceuthobium vaginatum | (Humb. & Bonpl. ex Willd.) J.Presl | Santalaceae | 8 |
| Archibaccharis auriculata | (Hemsl.) G.L.Nesom | Asteraceae | 8 |
| Archibaccharis serratifolia | S.F.Blake | Asteraceae | 8 |
| Arctostaphylos pungens | Kunth | Ericaceae | 8 |
| Ardisia compressa | Kunth | Primulaceae | 8 |
| Ardisia escallonioides | Schltdl. & Cham. | Primulaceae | 8 |
| Ardisia revoluta | Kunth | Primulaceae | 8 |
| Arenaria benthamii | Fenzl ex Torr. & A.Gray | Caryophyllaceae | 8 |
| Arenaria digyna | Willd. ex D.F.K.Schltdl. | Caryophyllaceae | 8 |
| Arenaria lanuginosa | (Michx.) Rohrb. | Caryophyllaceae | 8 |
| Arenaria lycopodioides | Willd. ex D.F.K.Schltdl. | Caryophyllaceae | 8 |
| Arenaria paludicola | B.L.Rob. | Caryophyllaceae | 8 |
| Argemone aenea | Ownbey | Papaveraceae | 8 |
| Argemone grandiflora | Sweet | Papaveraceae | 8 |
| Argemone ochroleuca | Sweet | Papaveraceae | 8 |
| Argemone platyceras | Link & Otto | Papaveraceae | 8 |
| Argemone pleiacantha | Greene | Papaveraceae | 8 |
| Argemone sanguinea | Greene | Papaveraceae | 8 |
| Argentina anserina | (L.) Rydb. | Rosaceae | 8 |
| Argyrochosma fendleri | (Kunze) Windham | Pteridaceae | 8 |
| Argyrochosma limitanea | (Maxon) Windham | Pteridaceae | 8 |
| Argyrochosma microphylla | (Kuhn) Windham | Pteridaceae | 8 |
| Ariocarpus kotschoubeyanus | (Lem.) K.Schum. | Cactaceae | 8 |
| Ariocarpus retusus | Scheidw. | Cactaceae | 8 |
| Ariocarpus trigonus | (F.A.C.Weber) K.Schum. | Cactaceae | 8 |
| Arisaema dracontium | (L.) Schott | Araceae | 8 |
| Aristida adscensionis | L. | Poaceae | 8 |
| Aristida arizonica | Vasey | Poaceae | 8 |
| Aristida divaricata | Humb. & Bonpl. ex Willd. | Poaceae | 8 |
| Aristida longespica | Poir. | Poaceae | 8 |
| Aristida oligantha | Michx. | Poaceae | 8 |
| Aristida pansa | Wooton & Standl. | Poaceae | 8 |
| Aristida purpurea | Nutt. | Poaceae | 8 |
| Aristida ternipes | Cav. | Poaceae | 8 |
| Aristolochia coryi | I.M.Johnst. | Aristolochiaceae | 8 |
| Aristolochia erecta | L. | Aristolochiaceae | 8 |
| Aristolochia foetida | Kunth | Aristolochiaceae | 8 |
| Aristolochia grandiflora | Sw. | Aristolochiaceae | 8 |
| Aristolochia pentandra | Jacq. | Aristolochiaceae | 8 |
| Aristolochia versabilifolia | Pfeifer | Aristolochiaceae | 8 |
| Aristolochia watsonii | Wooton & Standl. | Aristolochiaceae | 8 |
| Aristolochia wrightii | Seem. | Aristolochiaceae | 8 |
| Arracacia aegopodioides | (Kunth) J.M.Coult. & Rose | Apiaceae | 8 |
| Artemisia campestris | L. | Asteraceae | 8 |
| Artemisia carruthii | Alph.Wood ex J.H.Carruth | Asteraceae | 8 |
| Artemisia dracunculus | L. | Asteraceae | 8 |
| Artemisia filifolia | Torr. | Asteraceae | 8 |
| Artemisia ludoviciana | Nutt. | Asteraceae | 8 |
| Arthrostemma ciliatum | Pav. ex D.Don | Melastomataceae | 8 |
| Asclepias angustifolia | Schweigg. | Apocynaceae | 8 |
| Asclepias arenaria | Torr. | Apocynaceae | 8 |
| Asclepias asperula | (Decne.) Woodson | Apocynaceae | 8 |
| Asclepias brachystephana | Engelm. ex Torr. | Apocynaceae | 8 |
| Asclepias curassavica | L. | Apocynaceae | 8 |
| Asclepias emoryi | (Greene) Vail | Apocynaceae | 8 |
| Asclepias engelmanniana | Woodson | Apocynaceae | 8 |
| Asclepias fournieri | Woodson | Apocynaceae | 8 |
| Asclepias glaucescens | Kunth | Apocynaceae | 8 |
| Asclepias hypoleuca | (A.Gray) Woodson | Apocynaceae | 8 |
| Asclepias incarnata | L. | Apocynaceae | 8 |
| Asclepias involucrata | Engelm. ex Torr. | Apocynaceae | 8 |
| Asclepias latifolia | (Torr.) Raf. | Apocynaceae | 8 |
| Asclepias lemmonii | A.Gray | Apocynaceae | 8 |
| Asclepias linaria | Cav. | Apocynaceae | 8 |
| Asclepias linearis | Scheele | Apocynaceae | 8 |
| Asclepias nummularia | Torr. | Apocynaceae | 8 |
| Asclepias oenotheroides | Schltdl. & Cham. | Apocynaceae | 8 |
| Asclepias otarioides | E.Fourn. | Apocynaceae | 8 |
| Asclepias pellucida | E.Fourn. | Apocynaceae | 8 |
| Asclepias pratensis | Benth. | Apocynaceae | 8 |
| Asclepias prostrata | W.H.Blackw. | Apocynaceae | 8 |
| Asclepias senecionifolia | M.E.Jones | Apocynaceae | 8 |
| Asclepias similis | Hemsl. | Apocynaceae | 8 |
| Asclepias subverticillata | (A.Gray) Vail | Apocynaceae | 8 |
| Asclepias texana | A.Heller | Apocynaceae | 8 |
| Asclepias tuberosa | L. | Apocynaceae | 8 |
| Asclepias viridiflora | Raf. | Apocynaceae | 8 |
| Asemeia floribunda | (Benth.) J.F.B.Pastore & J.R.Abbott | Polygalaceae | 8 |
| Aspicarpa albida | (Cham. & Schltdl.) Hassl. | Malpighiaceae | 8 |
| Aspicarpa cynanchoides | (Kunth) Hassl. | Malpighiaceae | 8 |
| Aspicarpa hirtella | Rich. | Malpighiaceae | 8 |
| Aspicarpa hyssopifolia | A.Gray | Malpighiaceae | 8 |
| Asplenium adiantum-nigrum | L. | Aspleniaceae | 8 |
| Asplenium fragrans | Sw. | Aspleniaceae | 8 |
| Asplenium monanthes | L. | Aspleniaceae | 8 |
| Asplenium praemorsum | Sw. | Aspleniaceae | 8 |
| Asplenium resiliens | Kunze | Aspleniaceae | 8 |
| Asplenium scolopendrium | L. | Aspleniaceae | 8 |
| Asplenium serra | Langsd. & Fisch. | Aspleniaceae | 8 |
| Asplenium trichomanes | L. | Aspleniaceae | 8 |
| Aster moranensis | Kunth | Asteraceae | 8 |
| Aster subulatus | Michx. | Asteraceae | 8 |
| Asterohyptis stellulata | (Benth.) Epling | Lamiaceae | 8 |
| Astraea lobata | (L.) Klotzsch | Euphorbiaceae | 8 |
| Astragalus allochrous | A.Gray | Fabaceae | 8 |
| Astragalus amphioxys | A.Gray | Fabaceae | 8 |
| Astragalus cobrensis | A.Gray | Fabaceae | 8 |
| Astragalus crassicarpus | Nutt. | Fabaceae | 8 |
| Astragalus emoryanus | (Rydb.) Cory | Fabaceae | 8 |
| Astragalus greggii | S.Watson | Fabaceae | 8 |
| Astragalus humistratus | A.Gray | Fabaceae | 8 |
| Astragalus lentiginosus | Douglas ex Hook. | Fabaceae | 8 |
| Astragalus lotiflorus | Hook. | Fabaceae | 8 |
| Astragalus mollissimus | Torr. | Fabaceae | 8 |
| Astragalus nothoxys | A.Gray | Fabaceae | 8 |
| Astragalus nuttallianus | DC. | Fabaceae | 8 |
| Astragalus racemosus | Pursh | Fabaceae | 8 |
| Astragalus sanguineus | Rydb. | Fabaceae | 8 |
| Astragalus tephrodes | A.Gray | Fabaceae | 8 |
| Astragalus thurberi | A.Gray | Fabaceae | 8 |
| Astragalus wootonii | E.Sheld. | Fabaceae | 8 |
| Astranthium ciliatum | (Raf.) G.L.Nesom | Asteraceae | 8 |
| Astranthium xanthocomoides | (Less.) Larsen | Asteraceae | 8 |
| Astrolepis cochisensis | (Goodd.) D.M.Benham & Windham | Pteridaceae | 8 |
| Astrolepis integerrima | (Hook.) D.M.Benham & Windham | Pteridaceae | 8 |
| Astrolepis sinuata | (Lag. ex Sw.) D.M.Benham & Windham | Pteridaceae | 8 |
| Astronium graveolens | Jacq. | Anacardiaceae | 8 |
| Astrophytum asterias | (Zucc.) Lem. | Cactaceae | 8 |
| Astrophytum capricorne | (A.Dietr.) Britton & Rose | Cactaceae | 8 |
| Astrophytum myriostigma | Lem. | Cactaceae | 8 |
| Astrophytum ornatum | (DC.) Britton & Rose | Cactaceae | 8 |
| Atriplex acanthocarpa | (Torr.) S.Watson | Chenopodiaceae | 8 |
| Atriplex argentea | Nutt. | Chenopodiaceae | 8 |
| Atriplex canescens | (Pursh) Nutt. | Chenopodiaceae | 8 |
| Atriplex confertifolia | (Torr. & Frém.) S.Watson | Chenopodiaceae | 8 |
| Atriplex elegans | (Moq.) D.Dietr. | Chenopodiaceae | 8 |
| Atriplex obovata | Moq. | Chenopodiaceae | 8 |
| Augusta rivalis | (Benth.) J.H.Kirkbr. | Rubiaceae | 8 |
| Aulosepalum pyramidale | (Lindl.) M.A.Dix & M.W.Dix | Orchidaceae | 8 |
| Avicennia germinans | (L.) L. | Acanthaceae | 8 |
| Axonopus compressus | (Sw.) P.Beauv. | Poaceae | 8 |
| Axonopus fissifolius | (Raddi) Kuhlm. | Poaceae | 8 |
| Ayenia aculeata | (Jacq.) Christenh. & Byng | Malvaceae | 8 |
| Ayenia filiformis | S.Watson | Malvaceae | 8 |
| Ayenia limitaris | Cristóbal | Malvaceae | 8 |
| Ayenia micrantha | Standl. | Malvaceae | 8 |
| Ayenia microphylla | A.Gray | Malvaceae | 8 |
| Ayenia ovata | Hemsl. | Malvaceae | 8 |
| Azolla filiculoides | Lam. | Salviniaceae | 8 |
| Baccharis conferta | Kunth | Asteraceae | 8 |
| Baccharis halimifolia | L. | Asteraceae | 8 |
| Baccharis heterophylla | Kunth | Asteraceae | 8 |
| Baccharis neglecta | Britton | Asteraceae | 8 |
| Baccharis pteronioides | DC. | Asteraceae | 8 |
| Baccharis salicifolia | (Ruiz & Pav.) Pers. | Asteraceae | 8 |
| Baccharis salicina | Torr. & A.Gray | Asteraceae | 8 |
| Baccharis sarothroides | A.Gray | Asteraceae | 8 |
| Baccharis texana | A.Gray | Asteraceae | 8 |
| Baccharis thesioides | Kunth | Asteraceae | 8 |
| Baccharis trinervis | Pers. | Asteraceae | 8 |
| Baccharis wrightii | A.Gray | Asteraceae | 8 |
| Bacopa monnieri | (L.) Wettst. | Plantaginaceae | 8 |
| Baltimora recta | L. | Asteraceae | 8 |
| Barkleyanthus salicifolius | (Kunth) H.Rob. & Brettell | Asteraceae | 8 |
| Barleria oenotheroides | Dum.Cours. | Acanthaceae | 8 |
| Bartlettia scaposa | A.Gray | Asteraceae | 8 |
| Bartlettina sordida | (Less.) R.M.King & H.Rob. | Asteraceae | 8 |
| Bartlettina tuerckheimii | (Klatt) R.M.King & H.Rob. | Asteraceae | 8 |
| Batis maritima | L. | Bataceae | 8 |
| Bauhinia divaricata | L. | Fabaceae | 8 |
| Bauhinia lunarioides | A.Gray ex S.Watson | Fabaceae | 8 |
| Bauhinia macranthera | Benth. ex Hemsl. | Fabaceae | 8 |
| Bauhinia pauletia | Pers. | Fabaceae | 8 |
| Bauhinia ungulata | L. | Fabaceae | 8 |
| Beaucarnea recurvata | (K.Koch & Fintelm.) Lem. | Asparagaceae | 8 |
| Bebbia juncea | Greene | Asteraceae | 8 |
| Begonia angustiloba | A.DC. | Begoniaceae | 8 |
| Begonia balmisiana | F.X.d.Bálmis | Begoniaceae | 8 |
| Begonia fischeri | Schrank | Begoniaceae | 8 |
| Begonia glabra | Aubl. | Begoniaceae | 8 |
| Begonia gracilis | Kunth | Begoniaceae | 8 |
| Begonia heracleifolia | Schltdl. & Cham. | Begoniaceae | 8 |
| Begonia incarnata | Link & Otto | Begoniaceae | 8 |
| Begonia nelumbiifolia | Schltdl. & Cham. | Begoniaceae | 8 |
| Begonia plebeja | Liebm. | Begoniaceae | 8 |
| Begonia tapatia | Burt-Utley & McVaugh | Begoniaceae | 8 |
| Begonia uniflora | S.Watson | Begoniaceae | 8 |
| Bejaria aestuans | Mutis | Ericaceae | 8 |
| Beloglottis costaricensis | (Rchb.f.) Schltr. | Orchidaceae | 8 |
| Berberis haematocarpa | Wooton | Berberidaceae | 8 |
| Berberis hemsleyi | Donn.Sm. | Berberidaceae | 8 |
| Berberis pinifolia | (Lundell) C.H.Mull. | Berberidaceae | 8 |
| Berberis trifoliolata | Moric. | Berberidaceae | 8 |
| Berberis wilcoxii | Kearney | Berberidaceae | 8 |
| Berlandiera lyrata | Benth. | Asteraceae | 8 |
| Bernardia incana | C.V.Morton | Euphorbiaceae | 8 |
| Bernardia myricifolia | (Scheele) S.Watson | Euphorbiaceae | 8 |
| Bernardia obovata | I.M.Johnst. | Euphorbiaceae | 8 |
| Bernardia viridis | Millsp. | Euphorbiaceae | 8 |
| Berula erecta | (Huds.) Coville | Apiaceae | 8 |
| Beschorneria yuccoides | K.Koch | Asparagaceae | 8 |
| Bessera elegans | Schult.f. | Asparagaceae | 8 |
| Bidens aequisquama | (Fernald) Sherff | Asteraceae | 8 |
| Bidens alba | DC. | Asteraceae | 8 |
| Bidens aurea | (Aiton) Sherff | Asteraceae | 8 |
| Bidens bigelovii | A.Gray | Asteraceae | 8 |
| Bidens laevis | (L.) Britton, Sterns & Poggenb. | Asteraceae | 8 |
| Bidens leptocephala | Sherff | Asteraceae | 8 |
| Bidens ostruthioides | Sch.Bip. | Asteraceae | 8 |
| Bidens pilosa | L. | Asteraceae | 8 |
| Bidens reptans | G.Don | Asteraceae | 8 |
| Bidens serrulata | (Poir.) Desf. | Asteraceae | 8 |
| Bidens tenuisecta | A.Gray | Asteraceae | 8 |
| Bidens triplinervia | Kunth | Asteraceae | 8 |
| Billieturnera helleri | (Rose ex Heller) Fryxell | Malvaceae | 8 |
| Bixa orellana | L. | Bixaceae | 8 |
| Blechnum appendiculatum | Willd. | Blechnaceae | 8 |
| Blechnum occidentale | L. | Blechnaceae | 8 |
| Bletia arizonica | (S.Watson) Sosa & M.W.Chase | Orchidaceae | 8 |
| Bletia campanulata | Lex. | Orchidaceae | 8 |
| Bletia mexicana | (Greenm.) Sosa & M.W.Chase | Orchidaceae | 8 |
| Bletia nitida | (L.O.Williams) Sosa & M.W.Chase | Orchidaceae | 8 |
| Bletia purpurata | A.Rich. & Galeotti | Orchidaceae | 8 |
| Bletia purpurea | (Lam.) A.DC. | Orchidaceae | 8 |
| Bletia roezlii | Rchb.f. | Orchidaceae | 8 |
| Bletia warnockii | (Ames & Correll) Sosa & M.W.Chase | Orchidaceae | 8 |
| Blitum nuttallianum | Schult. | Chenopodiaceae | 8 |
| Blumea viscosa | (Mill.) V.M.Badillo | Asteraceae | 8 |
| Bocconia arborea | S.Watson | Papaveraceae | 8 |
| Bocconia frutescens | L. | Papaveraceae | 8 |
| Bocconia latisepala | S.Watson | Papaveraceae | 8 |
| Boechera perennans | (S.Watson) W.A.Weber | Brassicaceae | 8 |
| Boehmeria cylindrica | (L.) Sw. | Urticaceae | 8 |
| Boerhavia coccinea | Mill. | Nyctaginaceae | 8 |
| Boerhavia coulteri | (Hook.f.) S.Watson | Nyctaginaceae | 8 |
| Boerhavia diffusa | L. | Nyctaginaceae | 8 |
| Boerhavia erecta | L. | Nyctaginaceae | 8 |
| Boerhavia gracillima | Heimerl | Nyctaginaceae | 8 |
| Boerhavia linearifolia | A.Gray | Nyctaginaceae | 8 |
| Boerhavia purpurascens | A.Gray | Nyctaginaceae | 8 |
| Boerhavia scandens | L. | Nyctaginaceae | 8 |
| Boerhavia triquetra | S.Watson | Nyctaginaceae | 8 |
| Boerhavia wrightii | A.Gray | Nyctaginaceae | 8 |
| Bolboschoenus fluviatilis | (Torr.) Soják | Cyperaceae | 8 |
| Bomarea acutifolia | Herb. | Alstroemeriaceae | 8 |
| Bomarea edulis | (Tussac) Herb. | Alstroemeriaceae | 8 |
| Bommeria hispida | Underw. | Pteridaceae | 8 |
| Bommeria pedata | (Sw.) Fourn. | Pteridaceae | 8 |
| Bonamia ovalifolia | (Torr.) Hallier f. | Convolvulaceae | 8 |
| Bonellia macrocarpa | (Cav.) B.Ståhl & Källersjö | Primulaceae | 8 |
| Bonplandia geminiflora | Cav. | Polemoniaceae | 8 |
| Borrichia arborescens | (L.) DC. | Asteraceae | 8 |
| Borrichia frutescens | (L.) DC. | Asteraceae | 8 |
| Bothriochloa barbinodis | (Lag.) Herter | Poaceae | 8 |
| Bothriochloa hirtifolia | (J.Presl) Henrard | Poaceae | 8 |
| Bothriochloa hybrida | (Gould) Gould | Poaceae | 8 |
| Bothriochloa laguroides | (DC.) Herter | Poaceae | 8 |
| Bothriochloa longipaniculata | (Gould) Allred & Gould | Poaceae | 8 |
| Bothriochloa torreyana | (Steud.) Scrivanti & Anton | Poaceae | 8 |
| Botrychium minganense | Vict. | Ophioglossaceae | 8 |
| Botrypus virginianus | (L.) Michx. | Ophioglossaceae | 8 |
| Bouchea linifolia | A.Gray ex Torr. | Verbenaceae | 8 |
| Bouchea prismatica | (L.) Kuntze | Verbenaceae | 8 |
| Bouchetia arniatera | B.L.Rob. | Solanaceae | 8 |
| Bouchetia erecta | Dunal | Solanaceae | 8 |
| Bouteloua aristidoides | (Kunth) Griseb. | Poaceae | 8 |
| Bouteloua barbata | Lag. | Poaceae | 8 |
| Bouteloua chondrosioides | (Kunth) Benth. ex S.Watson | Poaceae | 8 |
| Bouteloua curtipendula | (Michx.) Torr. | Poaceae | 8 |
| Bouteloua dactyloides | (Nutt.) Columbus | Poaceae | 8 |
| Bouteloua eriopoda | (Torr.) Torr. | Poaceae | 8 |
| Bouteloua gracilis | (Kunth) Lag. ex Griffiths | Poaceae | 8 |
| Bouteloua hirsuta | Lag. | Poaceae | 8 |
| Bouteloua parryi | (E.Fourn.) Griffiths | Poaceae | 8 |
| Bouteloua polymorpha | (E.Fourn.) Columbus | Poaceae | 8 |
| Bouteloua repens | (Kunth) Scribn. & Merr. | Poaceae | 8 |
| Bouteloua rigidiseta | (Steud.) Hitchc. | Poaceae | 8 |
| Bouteloua scorpioides | Lag. | Poaceae | 8 |
| Bouteloua trifida | Thurb. ex S.Watson | Poaceae | 8 |
| Bouteloua uniflora | Vasey | Poaceae | 8 |
| Bouteloua warnockii | Gould & Kapadia | Poaceae | 8 |
| Bouvardia laevis | M.Martens & Galeotti | Rubiaceae | 8 |
| Bouvardia longiflora | (Cav.) Kunth | Rubiaceae | 8 |
| Bouvardia ternifolia | (Cav.) Schltdl. | Rubiaceae | 8 |
| Bowlesia incana | Ruiz & Pav. | Apiaceae | 8 |
| Brahea dulcis | (Kunth) Mart. | Arecaceae | 8 |
| Brandegea bigelovii | (S.Watson) Cogn. | Cucurbitaceae | 8 |
| Brasenia schreberi | J.F.Gmel. | Cabombaceae | 8 |
| Brassia verrucosa | Bateman ex Lindl. | Orchidaceae | 8 |
| Bravaisia berlandieriana | (Nees) T.F.Daniel | Acanthaceae | 8 |
| Brickellia betonicifolia | A.Gray | Asteraceae | 8 |
| Brickellia coulteri | A.Gray | Asteraceae | 8 |
| Brickellia cylindracea | A.Gray & Engelm. | Asteraceae | 8 |
| Brickellia eupatorioides | (L.) Shinners | Asteraceae | 8 |
| Brickellia grandiflora | Nutt. | Asteraceae | 8 |
| Brickellia laciniata | A.Gray | Asteraceae | 8 |
| Brickellia leptophylla | (Scheele) Shinn. | Asteraceae | 8 |
| Brickellia pendula | A.Gray | Asteraceae | 8 |
| Brickellia rusbyi | A.Gray | Asteraceae | 8 |
| Brickellia veronicaefolia | (Kunth) A.Gray | Asteraceae | 8 |
| Brickelliastrum fendleri | (A.Gray) R.M.King & H.Rob. | Asteraceae | 8 |
| Bromelia karatas | L. | Bromeliaceae | 8 |
| Bromelia pinguin | L. | Bromeliaceae | 8 |
| Bromus anomalus | Rupr. ex E.Fourn. | Poaceae | 8 |
| Bromus carinatus | Hook. & Arn. | Poaceae | 8 |
| Bromus texensis | (Shear) Hitchc. | Poaceae | 8 |
| Brongniartia riesebergii | Dorado | Fabaceae | 8 |
| Brosimum alicastrum | Sw. | Moraceae | 8 |
| Buchnera floridana | Gand. | Orobanchaceae | 8 |
| Buchnera pusilla | Kunth | Orobanchaceae | 8 |
| Buddleja americana | L. | Scrophulariaceae | 8 |
| Buddleja cordata | Kunth | Scrophulariaceae | 8 |
| Buddleja crotonoides | A.Gray | Scrophulariaceae | 8 |
| Buddleja marrubiifolia | Benth. | Scrophulariaceae | 8 |
| Buddleja scordioides | Kunth | Scrophulariaceae | 8 |
| Buddleja sessiliflora | Kunth | Scrophulariaceae | 8 |
| Bulbostylis capillaris | (L.) Kunth ex C.B.Clarke | Cyperaceae | 8 |
| Bunchosia palmeri | S.Watson | Malpighiaceae | 8 |
| Bursera bipinnata | (Moc. & Sessé ex DC.) Engl. | Burseraceae | 8 |
| Bursera copallifera | (Moc. & Sessé ex DC.) Bullock | Burseraceae | 8 |
| Bursera cuneata | (Schltdl.) Engl. | Burseraceae | 8 |
| Bursera excelsa | (Kunth) Engl. | Burseraceae | 8 |
| Bursera fagaroides | (Kunth) Engl. | Burseraceae | 8 |
| Bursera galeottiana | Engl. | Burseraceae | 8 |
| Bursera grandifolia | (Schltdl.) Engl. | Burseraceae | 8 |
| Bursera graveolens | (Kunth) Triana & Planch. | Burseraceae | 8 |
| Bursera hindsiana | (Benth.) Engl. | Burseraceae | 8 |
| Bursera kerberi | Engl. | Burseraceae | 8 |
| Bursera lancifolia | (Schltdl.) Engl. | Burseraceae | 8 |
| Bursera microphylla | A.Gray | Burseraceae | 8 |
| Bursera morelensis | Ramírez | Burseraceae | 8 |
| Bursera multijuga | Engl. | Burseraceae | 8 |
| Bursera palmeri | S.Watson | Burseraceae | 8 |
| Bursera penicillata | (Sessé & Moc. ex DC.) Engl. | Burseraceae | 8 |
| Bursera simaruba | (L.) Sarg. | Burseraceae | 8 |
| Byrsonima crassifolia | (L.) Kunth | Malpighiaceae | 8 |
| Cabomba caroliniana | A.Gray | Cabombaceae | 8 |
| Calamagrostis purpurascens | R.Br. | Poaceae | 8 |
| Calandrinia ciliata | (Ruiz & Pav.) DC. | Montiaceae | 8 |
| Calanthe calanthoides | (A.Rich. & Galeotti) Hamer & Garay | Orchidaceae | 8 |
| Calceolaria mexicana | Benth. | Calceolariaceae | 8 |
| Calceolaria tripartita | Ruiz & Pav. | Calceolariaceae | 8 |
| Calea ternifolia | Kunth | Asteraceae | 8 |
| Calea urticifolia | (Mill.) DC. | Asteraceae | 8 |
| Callaeum macropterum | (DC.) D.M.Johnson | Malpighiaceae | 8 |
| Calliandra calothyrsus | Meisn. | Fabaceae | 8 |
| Calliandra eriophylla | Benth. | Fabaceae | 8 |
| Calliandra hirsuta | (G.Don) Benth. | Fabaceae | 8 |
| Calliandra houstoniana | (Mill.) Standl. | Fabaceae | 8 |
| Calliandra humilis | Benth. | Fabaceae | 8 |
| Callianthe purpusii | (Standl.) Donnell | Malvaceae | 8 |
| Callicarpa acuminata | Kunth | Lamiaceae | 8 |
| Callirhoe involucrata | (Torr. & A.Gray) A.Gray | Malvaceae | 8 |
| Callisia fragrans | (Lindl.) Woodson | Commelinaceae | 8 |
| Callisia micrantha | (Torr.) D.R.Hunt | Commelinaceae | 8 |
| Callisia navicularis | (Ortgies) D.R.Hunt | Commelinaceae | 8 |
| Callisia repens | (Jacq.) L. | Commelinaceae | 8 |
| Callitriche heterophylla | Pursh | Plantaginaceae | 8 |
| Callitriche palustris | L. | Plantaginaceae | 8 |
| Calochortus barbatus | (Kunth) Painter | Liliaceae | 8 |
| Calochortus kennedyi | Porter | Liliaceae | 8 |
| Calochortus purpureus | (Kunth) Baker | Liliaceae | 8 |
| Calopogonium caeruleum | (Benth.) C.Wright | Fabaceae | 8 |
| Calopogonium mucunoides | Desv. | Fabaceae | 8 |
| Calyptocarpus vialis | Less. | Asteraceae | 8 |
| Calystegia silvatica | Griseb. | Convolvulaceae | 8 |
| Camonea umbellata | (L.) A.R.Simões & Staples | Convolvulaceae | 8 |
| Campanula petiolata | A.DC. | Campanulaceae | 8 |
| Campuloclinium macrocephalum | DC. | Asteraceae | 8 |
| Campyloneurum angustifolium | (Sw.) Fée | Polypodiaceae | 8 |
| Campyloneurum phyllitidis | (L.) C.Presl | Polypodiaceae | 8 |
| Canavalia rosea | (Sw.) DC. | Fabaceae | 8 |
| Canavalia septentrionalis | J.D.Sauer | Fabaceae | 8 |
| Canavalia villosa | Benth. | Fabaceae | 8 |
| Canna indica | L. | Cannaceae | 8 |
| Canna tuerckheimii | Kraenzl. | Cannaceae | 8 |
| Cantinoa mutabilis | (Rich.) Harley & J.F.B.Pastore | Lamiaceae | 8 |
| Caperonia palustris | A.St.-Hil. | Euphorbiaceae | 8 |
| Capraria biflora | L. | Scrophulariaceae | 8 |
| Capraria frutescens | (Mill.) Briq. | Scrophulariaceae | 8 |
| Capraria mexicana | Moric. ex Benth. | Scrophulariaceae | 8 |
| Capsicum annuum | L. | Solanaceae | 8 |
| Cardamine auriculata | S.Watson | Brassicaceae | 8 |
| Cardamine breweri | S.Watson | Brassicaceae | 8 |
| Cardiospermum corindum | L. | Sapindaceae | 8 |
| Cardiospermum grandiflorum | Sw. | Sapindaceae | 8 |
| Cardiospermum halicacabum | L. | Sapindaceae | 8 |
| Carex albicans | Willd. ex Spreng. | Cyperaceae | 8 |
| Carex aureolensis | Steud. | Cyperaceae | 8 |
| Carex bella | L.H.Bailey | Cyperaceae | 8 |
| Carex brevior | (Dewey) Mack. ex Lunell | Cyperaceae | 8 |
| Carex bromoides | Willd. | Cyperaceae | 8 |
| Carex capitata | Sol. | Cyperaceae | 8 |
| Carex comosa | Boott | Cyperaceae | 8 |
| Carex densa | (L.H.Bailey) L.H.Bailey | Cyperaceae | 8 |
| Carex emoryi | Dewey | Cyperaceae | 8 |
| Carex frankii | Kunth | Cyperaceae | 8 |
| Carex hamata | Sw. | Cyperaceae | 8 |
| Carex hystericina | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex interior | L.H.Bailey | Cyperaceae | 8 |
| Carex leptopoda | Mack. | Cyperaceae | 8 |
| Carex longii | Mack. | Cyperaceae | 8 |
| Carex lupulina | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex lurida | Wahlenb. | Cyperaceae | 8 |
| Carex meadii | Dewey | Cyperaceae | 8 |
| Carex microdonta | Torr. | Cyperaceae | 8 |
| Carex microptera | Mack. | Cyperaceae | 8 |
| Carex muehlenbergii | Schkuhr ex Willd. | Cyperaceae | 8 |
| Carex occidentalis | L.H.Bailey | Cyperaceae | 8 |
| Carex pellita | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex planostachys | Kunze | Cyperaceae | 8 |
| Carex polystachya | Sw. ex Wahlenb. | Cyperaceae | 8 |
| Carex praegracilis | W.Boott | Cyperaceae | 8 |
| Carex spissa | L.H.Bailey ex Hemsl. | Cyperaceae | 8 |
| Carex utriculata | Boott | Cyperaceae | 8 |
| Carex vallicola | Dewey | Cyperaceae | 8 |
| Carlowrightia arizonica | A.Gray | Acanthaceae | 8 |
| Carlowrightia linearifolia | (Torr.) A.Gray | Acanthaceae | 8 |
| Carlowrightia neesiana | (Schauer) T.F.Daniel | Acanthaceae | 8 |
| Carlowrightia parviflora | (Buckley) Wassh. | Acanthaceae | 8 |
| Carlowrightia texana | Henrickson & T.F.Daniel | Acanthaceae | 8 |
| Carlowrightia torreyana | Wassh. | Acanthaceae | 8 |
| Carminatia tenuiflora | DC. | Asteraceae | 8 |
| Carnegiea gigantea | (Engelm.) Britton & Rose | Cactaceae | 8 |
| Carphochaete bigelovii | A.Gray | Asteraceae | 8 |
| Carpinus tropicalis | (Donn.Sm.) Lundell | Betulaceae | 8 |
| Carya illinoinensis | (Wangenh.) K.Koch | Juglandaceae | 8 |
| Carya myristiciformis | (F.Michx.) Nutt. ex Elliott | Juglandaceae | 8 |
| Carya ovata | (Mill.) K.Koch | Juglandaceae | 8 |
| Cascabela ovata | (Cav.) Lippold | Apocynaceae | 8 |
| Cascabela thevetia | (L.) Lippold | Apocynaceae | 8 |
| Cascabela thevetioides | (Humb. & Bonpl.) Lippold | Apocynaceae | 8 |
| Casearia arguta | Kunth | Salicaceae | 8 |
| Casearia corymbosa | Kunth | Salicaceae | 8 |
| Casearia laetioides | (A.Rich.) Warb. | Salicaceae | 8 |
| Casearia sylvestris | Sw. | Salicaceae | 8 |
| Casimiroa edulis | La Llave | Rutaceae | 8 |
| Castela emoryi | (A.Gray) Moran & Felger | Simaroubaceae | 8 |
| Castela erecta | Turpin | Simaroubaceae | 8 |
| Castela tortuosa | Liebm. | Simaroubaceae | 8 |
| Castilla elastica | Cerv. | Moraceae | 8 |
| Castilleja arvensis | Schltdl. & Cham. | Orobanchaceae | 8 |
| Castilleja genevievana | G.L.Nesom | Orobanchaceae | 8 |
| Castilleja indivisa | Engelm. | Orobanchaceae | 8 |
| Castilleja integra | A.Gray | Orobanchaceae | 8 |
| Castilleja integrifolia | L.f. | Orobanchaceae | 8 |
| Castilleja lanata | A.Gray | Orobanchaceae | 8 |
| Castilleja mexicana | (Hemsl.) A.Gray | Orobanchaceae | 8 |
| Castilleja minor | (A.Gray) A.Gray | Orobanchaceae | 8 |
| Castilleja moranensis | Kunth | Orobanchaceae | 8 |
| Castilleja nelsonii | Eastw. | Orobanchaceae | 8 |
| Castilleja patriotica | Fernald | Orobanchaceae | 8 |
| Castilleja scorzonerifolia | Kunth | Orobanchaceae | 8 |
| Castilleja sessiliflora | Pursh | Orobanchaceae | 8 |
| Castilleja tenuiflora | Benth. | Orobanchaceae | 8 |
| Castilleja tenuifolia | M.Martens & Galeotti | Orobanchaceae | 8 |
| Catasetum integerrimum | Hook. | Orchidaceae | 8 |
| Catopsis sessiliflora | (Ruiz & Pav.) Mez | Bromeliaceae | 8 |
| Cayaponia attenuata | (Hook. & Arn.) Cogn. | Cucurbitaceae | 8 |
| Cayaponia racemosa | (Mill.) Cogn. | Cucurbitaceae | 8 |
| Ceanothus buxifolius | Willd. ex Schult. | Rhamnaceae | 8 |
| Ceanothus caeruleus | Lag. | Rhamnaceae | 8 |
| Ceanothus fendleri | A.Gray | Rhamnaceae | 8 |
| Ceanothus herbaceus | Raf. | Rhamnaceae | 8 |
| Ceanothus pauciflorus | DC. | Rhamnaceae | 8 |
| Cecropia obtusifolia | Bertol. | Urticaceae | 8 |
| Cecropia peltata | L. | Urticaceae | 8 |
| Cedrela dugesii | S.Watson | Meliaceae | 8 |
| Cedrela odorata | L. | Meliaceae | 8 |
| Cedrela salvadorensis | Standl. | Meliaceae | 8 |
| Ceiba pentandra | (L.) Gaertn. | Malvaceae | 8 |
| Celosia nitida | Vahl | Amaranthaceae | 8 |
| Celtis caudata | Planch. | Cannabaceae | 8 |
| Celtis iguanaea | (Jacq.) Sarg. | Cannabaceae | 8 |
| Celtis laevigata | Willd. | Cannabaceae | 8 |
| Celtis pallida | Torr. | Cannabaceae | 8 |
| Celtis reticulata | Torr. | Cannabaceae | 8 |
| Cenchrus echinatus | L. | Poaceae | 8 |
| Cenchrus latifolius | (Spreng.) Morrone | Poaceae | 8 |
| Cenchrus myosuroides | Kunth | Poaceae | 8 |
| Cenchrus spinifex | Cav. | Poaceae | 8 |
| Cenostigma eriostachys | (Benth.) Gagnon & G.P.Lewis | Fabaceae | 8 |
| Centella erecta | (L.f.) Fernald | Apiaceae | 8 |
| Centradenia grandifolia | (Schltdl.) Endl. | Melastomataceae | 8 |
| Centropogon grandidentatus | (Schltdl.) Zahlbr. | Campanulaceae | 8 |
| Centrosema plumieri | (Turpin ex Pers.) Benth. | Fabaceae | 8 |
| Centrosema pubescens | Benth. | Fabaceae | 8 |
| Centrosema virginianum | (L.) Benth. | Fabaceae | 8 |
| Cephalanthus occidentalis | L. | Rubiaceae | 8 |
| Cephalanthus salicifolius | Bonpl. | Rubiaceae | 8 |
| Cephalocereus polylophus | (DC.) Britton & Rose | Cactaceae | 8 |
| Cephalocereus senilis | (Haw.) Pfeiff. | Cactaceae | 8 |
| Cerastium brachypodum | (Engelm. ex A.Gray) B.L.Rob. | Caryophyllaceae | 8 |
| Cerastium nutans | Raf. | Caryophyllaceae | 8 |
| Ceratophyllum demersum | L. | Ceratophyllaceae | 8 |
| Cercis canadensis | L. | Fabaceae | 8 |
| Cercocarpus betuloides | Nutt. | Rosaceae | 8 |
| Cercocarpus breviflorus | A.Gray | Rosaceae | 8 |
| Cercocarpus macrophyllus | C.K.Schneid. | Rosaceae | 8 |
| Cercocarpus montanus | Raf. | Rosaceae | 8 |
| Cestrum aurantiacum | Lindl. | Solanaceae | 8 |
| Cestrum diurnum | L. | Solanaceae | 8 |
| Cestrum elegans | (Brongn. ex Neumann) Schltdl. | Solanaceae | 8 |
| Cestrum fasciculatum | (Schltdl.) Miers | Solanaceae | 8 |
| Cestrum nocturnum | L. | Solanaceae | 8 |
| Cestrum tomentosum | L.f. | Solanaceae | 8 |
| Cevallia sinuata | Lag. | Loasaceae | 8 |
| Chaetogastra longifolia | (Vahl) DC. | Melastomataceae | 8 |
| Chaetogastra naudiniana | Decne. | Melastomataceae | 8 |
| Chaetopappa ericoides | (Torr.) G.L.Nesom | Asteraceae | 8 |
| Chamaecrista absus | (L.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Chamaecrista calycioides | (DC. ex Collad.) Greene | Fabaceae | 8 |
| Chamaecrista desvauxii | (Collad.) Killip | Fabaceae | 8 |
| Chamaecrista flexuosa | (L.) Greene | Fabaceae | 8 |
| Chamaecrista greggii | (A.Gray) Pollard ex A.Heller | Fabaceae | 8 |
| Chamaecrista nictitans | (L.) Moench | Fabaceae | 8 |
| Chamaecrista rotundifolia | (Pers.) Greene | Fabaceae | 8 |
| Chamaesaracha coniodes | (Moric. ex Dunal) Benth. & Hook.f. ex B.D.Jacks. | Solanaceae | 8 |
| Chamaesaracha coronopus | (Dunal) A.Gray | Solanaceae | 8 |
| Chamaesaracha pallida | Averett | Solanaceae | 8 |
| Chamissoa altissima | Kunth | Amaranthaceae | 8 |
| Chaptalia nutans | (L.) Pol. | Asteraceae | 8 |
| Chaptalia texana | Greene | Asteraceae | 8 |
| Chascolytrum subaristatum | (Lam.) Desv. | Poaceae | 8 |
| Chasmanthium latifolium | (Michx.) H.O.Yates | Poaceae | 8 |
| Cheilanthes leucopoda | Link | Pteridaceae | 8 |
| Chenopodium berlandieri | Moq. | Chenopodiaceae | 8 |
| Chenopodium fremontii | S.Watson | Chenopodiaceae | 8 |
| Chenopodium incanum | (S.Watson) A.Heller | Chenopodiaceae | 8 |
| Chenopodium leptophyllum | (Nutt. ex Moq.) B.D.Jacks. | Chenopodiaceae | 8 |
| Chenopodium rubrum | L. | Chenopodiaceae | 8 |
| Chilopsis linearis | (Cav.) Sweet | Bignoniaceae | 8 |
| Chimaphila maculata | (L.) Pursh | Ericaceae | 8 |
| Chimaphila umbellata | (L.) W.P.C.Barton | Ericaceae | 8 |
| Chiococca alba | (L.) Hitchc. | Rubiaceae | 8 |
| Chiococca pachyphylla | Wernham | Rubiaceae | 8 |
| Chiranthodendron pentadactylon | Larreat. | Malvaceae | 8 |
| Chloracantha spinosa | (Benth.) G.L.Nesom | Asteraceae | 8 |
| Chloris andropogonoides | E.Fourn. | Poaceae | 8 |
| Chloris cucullata | Bisch. | Poaceae | 8 |
| Chloris verticillata | Nutt. | Poaceae | 8 |
| Chloris virgata | Sw. | Poaceae | 8 |
| Choisya dumosa | (Torr. & A.Gray) A.Gray | Rutaceae | 8 |
| Choisya ternata | Kunth | Rutaceae | 8 |
| Chromolaena collina | (DC.) R.M.King & H.Rob. | Asteraceae | 8 |
| Chromolaena odorata | (L.) R.M.King & H.Rob. | Asteraceae | 8 |
| Chromolaena pulchella | (Kunth) R.M.King & H.Rob. | Asteraceae | 8 |
| Chrysactinia mexicana | A.Gray | Asteraceae | 8 |
| Chrysobalanus icaco | L. | Chrysobalanaceae | 8 |
| Chrysophyllum mexicanum | Brandegee ex Standl. | Sapotaceae | 8 |
| Chrysophyllum oliviforme | L. | Sapotaceae | 8 |
| Chthamalia ojadapantha | (L.O.Alvarado, S.Islas & M.G.Chávez) S.Islas & M.G.Chávez | Apocynaceae | 8 |
| Chthamalia parviflora | (Torr.) L.O.Alvarado & E.B.Cortez | Apocynaceae | 8 |
| Chthamalia producta | (Torr.) L.O.Alvarado & E.B.Cortez | Apocynaceae | 8 |
| Chthamalia schaffneri | (A.Gray ex Hemsl.) L.O.Alvarado & M.G.Chávez | Apocynaceae | 8 |
| Cicuta douglasii | J.M.Coult. & Rose | Apiaceae | 8 |
| Cicuta maculata | L. | Apiaceae | 8 |
| Cipura campanulata | Ravenna | Iridaceae | 8 |
| Cirsium arizonicum | (A.Gray) Petr. | Asteraceae | 8 |
| Cirsium bicentenariale | Rzed. | Asteraceae | 8 |
| Cirsium coahuilense | Ownbey & Pinkava | Asteraceae | 8 |
| Cirsium ehrenbergii | Sch.Bip. | Asteraceae | 8 |
| Cirsium horridulum | Michx. | Asteraceae | 8 |
| Cirsium mexicanum | DC. | Asteraceae | 8 |
| Cirsium neomexicanum | A.Gray | Asteraceae | 8 |
| Cirsium ochrocentrum | A.Gray | Asteraceae | 8 |
| Cirsium pinetorum | Greenm. | Asteraceae | 8 |
| Cirsium pringlei | Petr. | Asteraceae | 8 |
| Cirsium rhaphilepis | Petr. | Asteraceae | 8 |
| Cirsium subcoriaceum | Sch.Bip. | Asteraceae | 8 |
| Cirsium texanum | Buckley | Asteraceae | 8 |
| Cirsium wheeleri | Petr. | Asteraceae | 8 |
| Cirsium zamoranense | Rzed. | Asteraceae | 8 |
| Cissampelos pareira | L. | Menispermaceae | 8 |
| Cissus alata | Jacq. | Vitaceae | 8 |
| Cissus microcarpa | Vahl | Vitaceae | 8 |
| Cissus tiliacea | Kunth | Vitaceae | 8 |
| Cissus trifoliata | (L.) L. | Vitaceae | 8 |
| Cissus verticillata | (L.) Nicolson & C.E.Jarvis | Vitaceae | 8 |
| Citharexylum berlandieri | B.L.Rob. | Verbenaceae | 8 |
| Citharexylum brachyanthum | (A.Gray ex Hemsl.) A.Gray | Verbenaceae | 8 |
| Citharexylum caudatum | L. | Verbenaceae | 8 |
| Cladium mariscus | (L.) Pohl | Cyperaceae | 8 |
| Clappia suaedifolia | A.Gray | Asteraceae | 8 |
| Claytonia perfoliata | Donn ex Willd. | Montiaceae | 8 |
| Claytonia rosea | Rydb. | Montiaceae | 8 |
| Clematis dioica | L. | Ranunculaceae | 8 |
| Clematis drummondii | Torr. & A.Gray | Ranunculaceae | 8 |
| Clematis ligusticifolia | Nutt. | Ranunculaceae | 8 |
| Clematis pitcheri | Torr. & A.Gray | Ranunculaceae | 8 |
| Cleome dodecandra | L. | Cleomaceae | 8 |
| Cleome serrata | Jacq. | Cleomaceae | 8 |
| Cleome uniglandulosa | Cav. | Cleomaceae | 8 |
| Cleomella longipes | Torr. | Cleomaceae | 8 |
| Cleomella multicaulis | (DC.) J.C.Hall & Roalson | Cleomaceae | 8 |
| Cleomella refracta | (Engelm.) J.C.Hall & Roalson | Cleomaceae | 8 |
| Clethra mexicana | DC. | Clethraceae | 8 |
| Clethra rosei | Britton | Clethraceae | 8 |
| Cleyera theoides | (Sw.) Choisy | Pentaphylacaceae | 8 |
| Clinopodium brownei | (Sw.) Kuntze | Lamiaceae | 8 |
| Clinopodium macrostemum | (Moc. & Sessé ex Benth.) Kuntze | Lamiaceae | 8 |
| Clinopodium mexicanum | (Benth.) Govaerts | Lamiaceae | 8 |
| Clitoria mariana | L. | Fabaceae | 8 |
| Clusia salvinii | Donn.Sm. | Clusiaceae | 8 |
| Cnidoscolus aconitifolius | (Mill.) I.M.Johnst. | Euphorbiaceae | 8 |
| Cnidoscolus angustidens | Torr. | Euphorbiaceae | 8 |
| Cnidoscolus multilobus | (Pax) I.M.Johnst. | Euphorbiaceae | 8 |
| Cnidoscolus texanus | Small | Euphorbiaceae | 8 |
| Cobaea scandens | Cav. | Polemoniaceae | 8 |
| Coccocypselum hirsutum | Bartl. ex DC. | Rubiaceae | 8 |
| Coccoloba diversifolia | Jacq. | Polygonaceae | 8 |
| Coccoloba uvifera | (L.) L. | Polygonaceae | 8 |
| Cochemiea conoidea | (DC.) P.B.Breslin & Majure | Cactaceae | 8 |
| Cochemiea grahamii | (Engelm.) Doweld | Cactaceae | 8 |
| Cochemiea sheldonii | (Britton & Rose) Doweld | Cactaceae | 8 |
| Cochemiea theresae | (Cutak) Doweld | Cactaceae | 8 |
| Cochliasanthus caracalla | (L.) Trew | Fabaceae | 8 |
| Cochlospermum vitifolium | (Willd.) Spreng. | Bixaceae | 8 |
| Cochlospermum wrightii | (A.Gray) Byng & Christenh. | Bixaceae | 8 |
| Cojoba arborea | (L.) Britton & Rose | Fabaceae | 8 |
| Coleataenia rigidula | (Bosc ex Nees) LeBlond | Poaceae | 8 |
| Cologania angustifolia | Kunth | Fabaceae | 8 |
| Cologania biloba | (Lindl.) G.Nicholson | Fabaceae | 8 |
| Cologania broussonetii | (Balb.) DC. | Fabaceae | 8 |
| Cologania obovata | Schltdl. | Fabaceae | 8 |
| Cologania procumbens | Kunth | Fabaceae | 8 |
| Colubrina arborescens | (Mill.) Sarg. | Rhamnaceae | 8 |
| Colubrina greggii | S.Watson | Rhamnaceae | 8 |
| Colubrina texensis | (Torr. & A.Gray) A.Gray | Rhamnaceae | 8 |
| Colubrina triflora | Brongn. | Rhamnaceae | 8 |
| Colubrina viridis | (M.E.Jones) M.C.Johnst. | Rhamnaceae | 8 |
| Columnea schiedeana | Schltdl. | Gesneriaceae | 8 |
| Comandra umbellata | (L.) Nutt. | Santalaceae | 8 |
| Comarostaphylis arbutoides | Lindl. | Ericaceae | 8 |
| Comarostaphylis discolor | (Hook.) Diggs | Ericaceae | 8 |
| Comarostaphylis glaucescens | (Kunth) Zucc. ex Klotzsch | Ericaceae | 8 |
| Comarostaphylis polifolia | (Kunth) Zucc. ex Klotzsch | Ericaceae | 8 |
| Combretum farinosum | Kunth | Combretaceae | 8 |
| Combretum fruticosum | (Loefl.) Stuntz | Combretaceae | 8 |
| Commelina dianthifolia | Redouté | Commelinaceae | 8 |
| Commelina erecta | L. | Commelinaceae | 8 |
| Commelina tuberosa | L. | Commelinaceae | 8 |
| Condalia correllii | M.C.Johnst. | Rhamnaceae | 8 |
| Condalia ericoides | (A.Gray) M.C.Johnst. | Rhamnaceae | 8 |
| Condalia hookeri | M.C.Johnst. | Rhamnaceae | 8 |
| Condalia spathulata | A.Gray | Rhamnaceae | 8 |
| Condalia velutina | I.M.Johnst. | Rhamnaceae | 8 |
| Condalia viridis | I.M.Johnst. | Rhamnaceae | 8 |
| Condalia warnockii | M.C.Johnst. | Rhamnaceae | 8 |
| Condea albida | (Kunth) Harley & J.F.B.Pastore | Lamiaceae | 8 |
| Condea verticillata | (Jacq.) Harley & J.F.B.Pastore | Lamiaceae | 8 |
| Conocarpus erectus | L. | Combretaceae | 8 |
| Conoclinium betonicifolium | (Mill.) R.M.King & H.Rob. | Asteraceae | 8 |
| Conoclinium greggii | Small | Asteraceae | 8 |
| Conopholis alpina | Liebm. | Orobanchaceae | 8 |
| Convolvulus crenatifolius | Ruiz & Pav. | Convolvulaceae | 8 |
| Convolvulus equitans | Benth. | Convolvulaceae | 8 |
| Conyza laevigata | (Rich.) Pruski | Asteraceae | 8 |
| Conzattia multiflora | (B.L.Rob.) Standl. | Fabaceae | 8 |
| Corallorhiza maculata | Raf. | Orchidaceae | 8 |
| Corallorhiza odontorhiza | (Willd.) Nutt. | Orchidaceae | 8 |
| Corallorhiza striata | Lindl. | Orchidaceae | 8 |
| Corallorhiza wisteriana | Conrad | Orchidaceae | 8 |
| Corchorus siliquosus | L. | Malvaceae | 8 |
| Cordia alliodora | (Ruiz & Pav.) Oken | Cordiaceae | 8 |
| Cordia boissieri | A.DC. | Cordiaceae | 8 |
| Cordia dentata | Poir. | Cordiaceae | 8 |
| Cordia gerascanthus | L. | Cordiaceae | 8 |
| Cordia parvifolia | A.DC. | Cordiaceae | 8 |
| Cordylanthus wrightii | A.Gray | Orobanchaceae | 8 |
| Coreocarpus arizonicus | S.F.Blake | Asteraceae | 8 |
| Coreopsis nuecensis | A.Heller | Asteraceae | 8 |
| Coreopsis tinctoria | Nutt. | Asteraceae | 8 |
| Coriaria ruscifolia | L. | Coriariaceae | 8 |
| Cornus disciflora | Moc. & Sessé ex DC. | Cornaceae | 8 |
| Cornus excelsa | Kunth | Cornaceae | 8 |
| Cornus florida | L. | Cornaceae | 8 |
| Cornus sericea | L. | Cornaceae | 8 |
| Corydalis aurea | Willd. | Papaveraceae | 8 |
| Corydalis curvisiliqua | (A.Gray) Engelm. ex A.Gray | Papaveraceae | 8 |
| Corydalis micrantha | (Engelm. ex A.Gray) A.Gray ex J.M.Coult. | Papaveraceae | 8 |
| Coryphantha compacta | (Engelm.) Orcutt | Cactaceae | 8 |
| Coryphantha delaetiana | (Quehl) A.Berger | Cactaceae | 8 |
| Coryphantha delicata | L.Bremer | Cactaceae | 8 |
| Coryphantha difficilis | (Quehl) Orcutt | Cactaceae | 8 |
| Coryphantha durangensis | (Runge ex K.Schum.) Britton & Rose | Cactaceae | 8 |
| Coryphantha echinoidea | (Quehl) Britton & Rose | Cactaceae | 8 |
| Coryphantha echinus | (Engelm.) Britton & Rose | Cactaceae | 8 |
| Coryphantha erecta | (Lem. ex Pfeiff.) Lem. | Cactaceae | 8 |
| Coryphantha georgii | Boed. | Cactaceae | 8 |
| Coryphantha kracikii | Halda, Chalupa & Kupčák | Cactaceae | 8 |
| Coryphantha neglecta | L.Bremer | Cactaceae | 8 |
| Coryphantha nickelsiae | (K.Brandegee) Britton & Rose | Cactaceae | 8 |
| Coryphantha octacantha | (DC.) Britton & Rose | Cactaceae | 8 |
| Coryphantha poselgeriana | (A.Dietr.) Britton & Rose | Cactaceae | 8 |
| Coryphantha robustispina | (Schott ex Engelm.) Britton & Rose | Cactaceae | 8 |
| Coryphantha salinensis | (Poselg.) Dicht & A.Lüthy | Cactaceae | 8 |
| Coryphantha sulcata | (Engelm.) Britton & Rose | Cactaceae | 8 |
| Cosmos bipinnatus | Cav. | Asteraceae | 8 |
| Cosmos caudatus | Kunth | Asteraceae | 8 |
| Cosmos crithmifolius | Kunth | Asteraceae | 8 |
| Cosmos diversifolius | Otto | Asteraceae | 8 |
| Cosmos scabiosoides | Kunth | Asteraceae | 8 |
| Cosmos sulphureus | Cav. | Asteraceae | 8 |
| Costus pictus | D.Don | Costaceae | 8 |
| Costus pulverulentus | C.Presl | Costaceae | 8 |
| Costus scaber | Ruiz & Pav. | Costaceae | 8 |
| Cottea pappophoroides | Kunth | Poaceae | 8 |
| Cottsia californica | (Benth.) W.R.Anderson & C.Davis | Malpighiaceae | 8 |
| Cottsia gracilis | (A.Gray) W.R.Anderson & C.Davis | Malpighiaceae | 8 |
| Cotula mexicana | (DC.) Cabrera | Asteraceae | 8 |
| Coulteria platyloba | (S.Watson) N.Zamora | Fabaceae | 8 |
| Coursetia axillaris | J.M.Coult. & Rose | Fabaceae | 8 |
| Coursetia caribaea | (Jacq.) Lavin | Fabaceae | 8 |
| Coursetia glandulosa | A.Gray | Fabaceae | 8 |
| Crassula aquatica | (L.) Schönland | Crassulaceae | 8 |
| Crataegus crus-galli | L. | Rosaceae | 8 |
| Crataegus mexicana | Moc. & Sessé ex DC. | Rosaceae | 8 |
| Crataegus tracyi | Ashe ex Eggl. | Rosaceae | 8 |
| Crataegus uniflora | Münchh. | Rosaceae | 8 |
| Crateva tapia | L. | Capparaceae | 8 |
| Crescentia alata | Kunth | Bignoniaceae | 8 |
| Crescentia cujete | L. | Bignoniaceae | 8 |
| Cressa truxillensis | Kunth | Convolvulaceae | 8 |
| Critonia hospitalis | (B.L.Rob.) R.M.King & H.Rob. | Asteraceae | 8 |
| Critonia morifolia | (Mill.) R.M.King & H.Rob. | Asteraceae | 8 |
| Critonia quadrangularis | (DC.) R.M.King & H.Rob. | Asteraceae | 8 |
| Crocanthemum canadense | (L.) Britton | Cistaceae | 8 |
| Crocanthemum glomeratum | (Lag.) Janch. | Cistaceae | 8 |
| Crossopetalum uragoga | (Jacq.) Kuntze | Celastraceae | 8 |
| Crossosoma bigelovii | S.Watson | Crossosomataceae | 8 |
| Crotalaria cajanifolia | Kunth | Fabaceae | 8 |
| Crotalaria incana | L. | Fabaceae | 8 |
| Crotalaria micans | Link | Fabaceae | 8 |
| Crotalaria mollicula | Kunth | Fabaceae | 8 |
| Crotalaria pumila | Ortega | Fabaceae | 8 |
| Crotalaria purshii | DC. | Fabaceae | 8 |
| Crotalaria rotundifolia | J.F.Gmel. | Fabaceae | 8 |
| Crotalaria sagittalis | L. | Fabaceae | 8 |
| Croton adspersus | Benth. | Euphorbiaceae | 8 |
| Croton arboreus | Millsp. | Euphorbiaceae | 8 |
| Croton argyranthemus | Michx. | Euphorbiaceae | 8 |
| Croton bigbendensis | B.L.Turner | Euphorbiaceae | 8 |
| Croton californicus | Müll.Arg. | Euphorbiaceae | 8 |
| Croton ciliatoglandulifer | Ortega | Euphorbiaceae | 8 |
| Croton cortesianus | Kunth | Euphorbiaceae | 8 |
| Croton dioicus | Cav. | Euphorbiaceae | 8 |
| Croton draco | Schltdl. | Euphorbiaceae | 8 |
| Croton fruticulosus | Torr. | Euphorbiaceae | 8 |
| Croton glandulosus | L. | Euphorbiaceae | 8 |
| Croton guatemalensis | Lotsy | Euphorbiaceae | 8 |
| Croton heliotropiifolius | Kunth | Euphorbiaceae | 8 |
| Croton heptalon | (Kuntze) B.W.van Ee & P.E.Berry | Euphorbiaceae | 8 |
| Croton humilis | L. | Euphorbiaceae | 8 |
| Croton incanus | Kunth | Euphorbiaceae | 8 |
| Croton leucophyllus | Müll.Arg. | Euphorbiaceae | 8 |
| Croton lindheimerianus | Scheele | Euphorbiaceae | 8 |
| Croton monanthogynus | Michx. | Euphorbiaceae | 8 |
| Croton pottsii | (Klotzsch) Müll.Arg. | Euphorbiaceae | 8 |
| Croton punctatus | Jacq. | Euphorbiaceae | 8 |
| Croton reflexifolius | Kunth | Euphorbiaceae | 8 |
| Croton sonorae | Torr. | Euphorbiaceae | 8 |
| Croton suaveolens | Torr. | Euphorbiaceae | 8 |
| Croton texensis | (Klotzsch) Müll.Arg. | Euphorbiaceae | 8 |
| Crusea hispida | (Mill.) B.L.Rob. | Rubiaceae | 8 |
| Crusea longiflora | (Roem. & Schult.) W.R.Anderson | Rubiaceae | 8 |
| Crusea simplex | (Willd.) J.H.Kirkbr. & Wiersema | Rubiaceae | 8 |
| Cryptantha crassisepala | (Torr. & A.Gray) Greene | Boraginaceae | 8 |
| Ctenodon viscidulus | (Michx.) D.B.O.S.Cardoso & A.Delgado | Fabaceae | 8 |
| Cucurbita argyrosperma | C.Huber | Cucurbitaceae | 8 |
| Cucurbita digitata | A.Gray | Cucurbitaceae | 8 |
| Cucurbita foetidissima | Kunth | Cucurbitaceae | 8 |
| Cucurbita moschata | Duchesne | Cucurbitaceae | 8 |
| Cucurbita pepo | L. | Cucurbitaceae | 8 |
| Cunila polyantha | Benth. | Lamiaceae | 8 |
| Cupania dentata | Moc. & Sessé | Sapindaceae | 8 |
| Cupania glabra | Sw. | Sapindaceae | 8 |
| Cuphea aequipetala | Cav. | Lythraceae | 8 |
| Cuphea appendiculata | Benth. | Lythraceae | 8 |
| Cuphea carthagenensis | (Jacq.) J.F.Macbr. | Lythraceae | 8 |
| Cuphea hookeriana | Walp. | Lythraceae | 8 |
| Cuphea hyssopifolia | Kunth | Lythraceae | 8 |
| Cuphea jorullensis | Kunth | Lythraceae | 8 |
| Cuphea leptopoda | Hemsl. | Lythraceae | 8 |
| Cuphea llavea | Lex. | Lythraceae | 8 |
| Cuphea procumbens | Ortega | Lythraceae | 8 |
| Cuphea racemosa | (L.f.) Spreng. | Lythraceae | 8 |
| Cuphea tolucana | Peyr. | Lythraceae | 8 |
| Cuphea viscosissima | Jacq. | Lythraceae | 8 |
| Cuphea wrightii | A.Gray | Lythraceae | 8 |
| Curatella americana | L. | Dilleniaceae | 8 |
| Cuscuta campestris | Yunck. | Convolvulaceae | 8 |
| Cuscuta cephalanthi | Engelm. | Convolvulaceae | 8 |
| Cuscuta indecora | Choisy | Convolvulaceae | 8 |
| Cuscuta umbellata | Kunth | Convolvulaceae | 8 |
| Cyclanthera carthagenensis | (Jacq.) H.Schaef. & S.S.Renner | Cucurbitaceae | 8 |
| Cyclopogon elatus | (Sw.) Schltr. | Orchidaceae | 8 |
| Cyclosorus interruptus | (Willd.) H.Itô | Thelypteridaceae | 8 |
| Cyclospermum leptophyllum | (Pers.) Sprague | Apiaceae | 8 |
| Cylindropuntia arbuscula | (Engelm.) F.M.Knuth | Cactaceae | 8 |
| Cylindropuntia fulgida | (Engelm.) F.M.Knuth | Cactaceae | 8 |
| Cylindropuntia imbricata | (Haw.) F.M.Knuth | Cactaceae | 8 |
| Cylindropuntia kleiniae | (DC.) F.M.Knuth | Cactaceae | 8 |
| Cylindropuntia leptocaulis | (DC.) F.M.Knuth | Cactaceae | 8 |
| Cylindropuntia pallida | (Rose) F.M.Knuth | Cactaceae | 8 |
| Cylindropuntia thurberi | (Engelm.) F.M.Knuth | Cactaceae | 8 |
| Cylindropuntia tunicata | (Lehm.) F.M.Knuth | Cactaceae | 8 |
| Cymopterus glomeratus | (Nutt.) DC. | Apiaceae | 8 |
| Cymopterus hallii | (A.Gray) B.L.Turner | Apiaceae | 8 |
| Cymopterus lemmonii | (J.M.Coult. & Rose) Dorn | Apiaceae | 8 |
| Cyperus acuminatus | Torr. & Hook. | Cyperaceae | 8 |
| Cyperus aggregatus | (Willd.) Endl. | Cyperaceae | 8 |
| Cyperus articulatus | L. | Cyperaceae | 8 |
| Cyperus bipartitus | Torr. | Cyperaceae | 8 |
| Cyperus entrerianus | Boeckeler | Cyperaceae | 8 |
| Cyperus esculentus | L. | Cyperaceae | 8 |
| Cyperus fendlerianus | Boeckeler | Cyperaceae | 8 |
| Cyperus flavescens | L. | Cyperaceae | 8 |
| Cyperus hermaphroditus | (Jacq.) Standl. | Cyperaceae | 8 |
| Cyperus laevigatus | L. | Cyperaceae | 8 |
| Cyperus lanceolatus | Poir. | Cyperaceae | 8 |
| Cyperus ligularis | L. | Cyperaceae | 8 |
| Cyperus luzulae | (L.) Retz. | Cyperaceae | 8 |
| Cyperus manimae | Kunth | Cyperaceae | 8 |
| Cyperus melanostachyus | Kunth | Cyperaceae | 8 |
| Cyperus ochraceus | Vahl | Cyperaceae | 8 |
| Cyperus odoratus | L. | Cyperaceae | 8 |
| Cyperus polystachyos | Rottb. | Cyperaceae | 8 |
| Cyperus prolixus | Kunth | Cyperaceae | 8 |
| Cyperus pseudothyrsiflorus | (Kük.) R.Carter & S.D.Jones | Cyperaceae | 8 |
| Cyperus retroflexus | Buckley | Cyperaceae | 8 |
| Cyperus retrorsus | Chapm. | Cyperaceae | 8 |
| Cyperus schweinitzii | Torr. | Cyperaceae | 8 |
| Cyperus seslerioides | Kunth | Cyperaceae | 8 |
| Cyperus sesquiflorus | (Torr.) Mattf. & Kük. | Cyperaceae | 8 |
| Cyperus sphaerolepis | Boeckeler | Cyperaceae | 8 |
| Cyperus squarrosus | L. | Cyperaceae | 8 |
| Cyperus subsquarrosus | (Muhl.) Bauters | Cyperaceae | 8 |
| Cyperus surinamensis | Rottb. | Cyperaceae | 8 |
| Cyperus tetragonus | Elliott | Cyperaceae | 8 |
| Cyperus thyrsiflorus | Jungh. | Cyperaceae | 8 |
| Cyperus virens | Michx. | Cyperaceae | 8 |
| Cyphomeris gypsophiloides | (M.Martens & Galeotti) Standl. | Nyctaginaceae | 8 |
| Cyrtopodium macrobulbon | (Lex.) G.A.Romero & Carnevali | Orchidaceae | 8 |
| Cystopteris fragilis | (L.) Bernh. | Cystopteridaceae | 8 |
| Cystopteris reevesiana | Lellinger | Cystopteridaceae | 8 |
| Dahlia coccinea | Cav. | Asteraceae | 8 |
| Dahlia imperialis | Roezl ex Ortgies | Asteraceae | 8 |
| Dahlia merckii | Lehm. | Asteraceae | 8 |
| Dahlia pinnata | Cav. | Asteraceae | 8 |
| Dahlia sherffii | P.D.Sørensen | Asteraceae | 8 |
| Dahlia sorensenii | H.V.Hansen & Hjert. | Asteraceae | 8 |
| Dalea albiflora | A.Gray | Fabaceae | 8 |
| Dalea aurea | Nutt. ex Pursh | Fabaceae | 8 |
| Dalea bicolor | Humb. & Bonpl. ex Willd. | Fabaceae | 8 |
| Dalea caeciliae | Harms | Fabaceae | 8 |
| Dalea candida | Willd. | Fabaceae | 8 |
| Dalea dorycnioides | DC. | Fabaceae | 8 |
| Dalea emarginata | (Torr. & A.Gray) Shinners | Fabaceae | 8 |
| Dalea foliolosa | (Aiton) Barneby | Fabaceae | 8 |
| Dalea formosa | Torr. | Fabaceae | 8 |
| Dalea frutescens | A.Gray | Fabaceae | 8 |
| Dalea greggii | A.Gray | Fabaceae | 8 |
| Dalea humilis | G.Don | Fabaceae | 8 |
| Dalea jamesii | (Torr.) Torr. & A.Gray | Fabaceae | 8 |
| Dalea lanata | Spreng. | Fabaceae | 8 |
| Dalea lasiathera | A.Gray | Fabaceae | 8 |
| Dalea leporina | (Aiton) Bullock | Fabaceae | 8 |
| Dalea leucosericea | (Rydb.) Standl. & Steyerm. | Fabaceae | 8 |
| Dalea lutea | (Cav.) Willd. | Fabaceae | 8 |
| Dalea mollis | Benth. | Fabaceae | 8 |
| Dalea multiflora | (Nutt.) Shinners | Fabaceae | 8 |
| Dalea nana | Torr. ex A.Gray | Fabaceae | 8 |
| Dalea neomexicana | (A.Gray) Cory | Fabaceae | 8 |
| Dalea obovata | (Torr. & A.Gray) Shinners | Fabaceae | 8 |
| Dalea obovatifolia | Ortega | Fabaceae | 8 |
| Dalea pogonathera | A.Gray | Fabaceae | 8 |
| Dalea polygonoides | A.Gray | Fabaceae | 8 |
| Dalea pringlei | A.Gray | Fabaceae | 8 |
| Dalea prostrata | Ortega | Fabaceae | 8 |
| Dalea rubescens | S.Watson | Fabaceae | 8 |
| Dalea sericea | Lag. | Fabaceae | 8 |
| Dalea urceolata | Greene | Fabaceae | 8 |
| Dalea versicolor | Zucc. | Fabaceae | 8 |
| Dalea wrightii | A.Gray | Fabaceae | 8 |
| Dalechampia scandens | L. | Euphorbiaceae | 8 |
| Damburneya coriacea | (Sw.) Trofimov & Rohwer | Lauraceae | 8 |
| Damburneya salicifolia | (Kunth) Trofimov & Rohwer | Lauraceae | 8 |
| Danthonia spicata | (L.) Roem. & Schult. | Poaceae | 8 |
| Daphnopsis americana | (Mill.) J.R.Johnst. | Thymelaeaceae | 8 |
| Dasylirion acrotrichum | (Schiede) Zucc. | Asparagaceae | 8 |
| Dasylirion berlandieri | S.Watson | Asparagaceae | 8 |
| Dasylirion cedrosanum | Trel. | Asparagaceae | 8 |
| Dasylirion leiophyllum | Engelm. ex Trel. | Asparagaceae | 8 |
| Dasylirion parryanum | Trel. | Asparagaceae | 8 |
| Dasylirion texanum | Scheele | Asparagaceae | 8 |
| Dasylirion wheeleri | S.Watson ex Rothr. | Asparagaceae | 8 |
| Datura ceratocaula | Ortega | Solanaceae | 8 |
| Datura discolor | Bernh. | Solanaceae | 8 |
| Datura ferox | L. | Solanaceae | 8 |
| Datura innoxia | Mill. | Solanaceae | 8 |
| Datura quercifolia | Kunth | Solanaceae | 8 |
| Datura stramonium | L. | Solanaceae | 8 |
| Datura wrightii | Regel | Solanaceae | 8 |
| Daucus pusillus | Michx. | Apiaceae | 8 |
| Dayia havardii | (A.Gray) J.M.Porter | Polemoniaceae | 8 |
| Decatropis bicolor | Radlk. | Rutaceae | 8 |
| Deiregyne eriophora | (B.L.Rob. & Greenm.) Garay | Orchidaceae | 8 |
| Delilia biflora | Kuntze | Asteraceae | 8 |
| Delphinium carolinianum | Walter | Ranunculaceae | 8 |
| Delphinium madrense | S.Watson | Ranunculaceae | 8 |
| Delphinium pedatisectum | Hemsl. | Ranunculaceae | 8 |
| Delphinium scopulorum | A.Gray | Ranunculaceae | 8 |
| Delphinium wootonii | Rydb. | Ranunculaceae | 8 |
| Dermatophyllum secundiflorum | (Ortega) Gandhi & Reveal | Fabaceae | 8 |
| Deschampsia danthonioides | (Trin.) Benth. | Poaceae | 8 |
| Deschampsia elongata | (Hook.) Munro | Poaceae | 8 |
| Descurainia incisa | (Engelm.) Britton | Brassicaceae | 8 |
| Descurainia pinnata | (Walter) Britton | Brassicaceae | 8 |
| Desmanthus bicornutus | S.Watson | Fabaceae | 8 |
| Desmanthus cooleyi | (Eaton) Trel. ex Branner & Coville | Fabaceae | 8 |
| Desmanthus velutinus | Scheele | Fabaceae | 8 |
| Desmanthus virgatus | (L.) Willd. | Fabaceae | 8 |
| Desmodium batocaulon | A.Gray | Fabaceae | 8 |
| Desmodium canescens | (L.) DC. | Fabaceae | 8 |
| Desmodium ciliare | (Muhl. ex Willd.) DC. | Fabaceae | 8 |
| Desmodium grahamii | A.Gray | Fabaceae | 8 |
| Desmodium incanum | (Sw.) DC. | Fabaceae | 8 |
| Desmodium intortum | (Mill.) Urb. | Fabaceae | 8 |
| Desmodium lindheimeri | Vail | Fabaceae | 8 |
| Desmodium lineatum | DC. | Fabaceae | 8 |
| Desmodium macrostachyum | Hemsl. | Fabaceae | 8 |
| Desmodium molliculum | (Kunth) DC. | Fabaceae | 8 |
| Desmodium orbiculare | Schltdl. | Fabaceae | 8 |
| Desmodium pringlei | S.Watson | Fabaceae | 8 |
| Desmodium procumbens | (Mill.) C.L.Hitchc. | Fabaceae | 8 |
| Desmodium psilophyllum | Schltdl. | Fabaceae | 8 |
| Desmodium rosei | B.G.Schub. | Fabaceae | 8 |
| Desmodium scorpiurus | (Sw.) Poir. | Fabaceae | 8 |
| Desmodium subsessile | Schltdl. | Fabaceae | 8 |
| Desmodium tortuosum | (Sw.) DC. | Fabaceae | 8 |
| Desmodium uncinatum | (Jacq.) DC. | Fabaceae | 8 |
| Dianthera americana | L. | Acanthaceae | 8 |
| Dianthera breviflora | (Nees) Hemsl. | Acanthaceae | 8 |
| Dianthera candicans | (Nees) Benth. & Hook.f. ex Hemsl. | Acanthaceae | 8 |
| Dianthera comata | L. | Acanthaceae | 8 |
| Dianthera ovata | Walter | Acanthaceae | 8 |
| Diaperia verna | (Raf.) Morefield | Asteraceae | 8 |
| Diastatea micrantha | (Kunth) McVaugh | Campanulaceae | 8 |
| Diastatea tenera | (A.Gray) McVaugh | Campanulaceae | 8 |
| Dichaea glauca | (Sw.) Lindl. | Orchidaceae | 8 |
| Dichanthelium aciculare | (Desv.) Gould & C.A.Clark | Poaceae | 8 |
| Dichanthelium acuminatum | (Sw.) Gould & C.A.Clark | Poaceae | 8 |
| Dichanthelium commutatum | (Schult.) Gould | Poaceae | 8 |
| Dichanthelium dichotomum | (L.) Gould | Poaceae | 8 |
| Dichanthelium ensifolium | (Baldwin ex Elliott) Gould | Poaceae | 8 |
| Dichanthelium lanuginosum | (Elliott) Gould | Poaceae | 8 |
| Dichanthelium laxiflorum | (Lam.) Gould | Poaceae | 8 |
| Dichanthelium lindheimeri | (Nash) Gould | Poaceae | 8 |
| Dichanthelium neuranthum | (Griseb.) LeBlond | Poaceae | 8 |
| Dichanthelium oligosanthes | (Schult.) Gould | Poaceae | 8 |
| Dichanthelium ovale | (Elliott) Gould & C.A.Clark | Poaceae | 8 |
| Dichanthelium portoricense | (Desv.) B.F.Hansen & Wunderlin | Poaceae | 8 |
| Dichondra argentea | Humb. & Bonpl. ex Willd. | Convolvulaceae | 8 |
| Dichondra brachypoda | Wooton & Standl. | Convolvulaceae | 8 |
| Dichondra sericea | Sw. | Convolvulaceae | 8 |
| Dichromanthus aurantiacus | (La Llave & Lex.) Salazar & Soto Arenas | Orchidaceae | 8 |
| Dichromanthus cinnabarinus | (La Llave & Lex.) Garay | Orchidaceae | 8 |
| Dichromanthus michuacanus | (La Llave & Lex.) Salazar & Soto Arenas | Orchidaceae | 8 |
| Dicliptera brachiata | Spreng. | Acanthaceae | 8 |
| Dicliptera peduncularis | Nees | Acanthaceae | 8 |
| Dicliptera resupinata | (Vahl) Juss. | Acanthaceae | 8 |
| Dicliptera sexangularis | (L.) Juss. | Acanthaceae | 8 |
| Dicranocarpus parviflorus | A.Gray | Asteraceae | 8 |
| Dictyanthus pavonii | Decne. | Apocynaceae | 8 |
| Dictyanthus reticulatus | (Turcz.) Benth. & Hook.f. ex Hemsl. | Apocynaceae | 8 |
| Dictyanthus sepicola | (W.D.Stevens) W.D.Stevens | Apocynaceae | 8 |
| Dieteria asteroides | Torr. | Asteraceae | 8 |
| Dieteria canescens | (Pursh) Nutt. | Asteraceae | 8 |
| Digitacalia jatrophoides | (Kunth) Pippen | Asteraceae | 8 |
| Digitaria californica | (Benth.) Henrard | Poaceae | 8 |
| Digitaria filiformis | (L.) Koeler | Poaceae | 8 |
| Digitaria insularis | (L.) Mez ex Ekman | Poaceae | 8 |
| Diodia virginiana | L. | Rubiaceae | 8 |
| Dioon angustifolium | Miq. | Zamiaceae | 8 |
| Dioon edule | Lindl. | Zamiaceae | 8 |
| Dioscorea densiflora | Hemsl. | Dioscoreaceae | 8 |
| Dioscorea mexicana | Scheidw. | Dioscoreaceae | 8 |
| Dioscorea spiculiflora | Hemsl. | Dioscoreaceae | 8 |
| Diospyros nigra | (J.F.Gmel.) Perr. & Perr. | Ebenaceae | 8 |
| Diospyros texana | Scheele | Ebenaceae | 8 |
| Diphasiastrum thyoides | (Willd.) Holub | Lycopodiaceae | 8 |
| Diphysa americana | (Mill.) M.Sousa | Fabaceae | 8 |
| Diphysa suberosa | S.Watson | Fabaceae | 8 |
| Diplachne fusca | (L.) P.Beauv. | Poaceae | 8 |
| Disakisperma dubium | (Kunth) P.M.Peterson & N.Snow | Poaceae | 8 |
| Disocactus anguliger | (Lem.) M.A.Cruz & S.Arias | Cactaceae | 8 |
| Disocactus crenatus | (Lindl.) M.A.Cruz & S.Arias | Cactaceae | 8 |
| Distichlis littoralis | (Engelm.) H.L.Bell & Columbus | Poaceae | 8 |
| Distichlis spicata | (L.) Greene | Poaceae | 8 |
| Distimake cissoides | (Lam.) A.R.Simões & Staples | Convolvulaceae | 8 |
| Distimake dissectus | (Jacq.) A.R.Simões & Staples | Convolvulaceae | 8 |
| Distimake quinquefolius | (L.) A.R.Simões & Staples | Convolvulaceae | 8 |
| Ditaxis humilis | (Engelm. & A.Gray) Pax | Euphorbiaceae | 8 |
| Ditaxis serrata | (Torr.) A.Heller | Euphorbiaceae | 8 |
| Ditaxis simulans | (J.W.Ingram) Radcl.-Sm. & Govaerts | Euphorbiaceae | 8 |
| Dodonaea viscosa | Jacq. | Sapindaceae | 8 |
| Dolichandra quadrivalvis | (Jacq.) L.G.Lohmann | Bignoniaceae | 8 |
| Dolichandra unguis-cati | (L.) L.G.Lohmann | Bignoniaceae | 8 |
| Dorstenia contrajerva | L. | Moraceae | 8 |
| Dorstenia drakena | L. | Moraceae | 8 |
| Draba helleriana | Greene | Brassicaceae | 8 |
| Drimys granadensis | L.f. | Winteraceae | 8 |
| Drymaria glandulosa | Bartl. | Caryophyllaceae | 8 |
| Drymaria leptophylla | (Cham. & Schltdl.) Fenzl ex Rohrb. | Caryophyllaceae | 8 |
| Drymaria molluginea | (Ser.) Didr. | Caryophyllaceae | 8 |
| Drymaria villosa | Cham. & Schltdl. | Caryophyllaceae | 8 |
| Dryopetalon runcinatum | A.Gray | Brassicaceae | 8 |
| Dryopteris filix-mas | (L.) Schott | Dryopteridaceae | 8 |
| Dryopteris wallichiana | (Spreng.) Hyl. | Dryopteridaceae | 8 |
| Drypetes lateriflora | (Sw.) Krug & Urb. | Putranjivaceae | 8 |
| Dugesia mexicana | A.Gray | Asteraceae | 8 |
| Duranta erecta | L. | Verbenaceae | 8 |
| Dyschoriste crenulata | Kobuski | Acanthaceae | 8 |
| Dyschoriste decumbens | (A.Gray) Kuntze | Acanthaceae | 8 |
| Dyschoriste hirsutissima | (Nees) Kuntze | Acanthaceae | 8 |
| Dyschoriste linearis | (Torr. & A.Gray) Kuntze | Acanthaceae | 8 |
| Dyschoriste microphylla | (Cav.) Kuntze | Acanthaceae | 8 |
| Dyschoriste schiedeana | (Nees) Kuntze | Acanthaceae | 8 |
| Dysphania ambrosioides | (L.) Mosyakin & Clemants | Chenopodiaceae | 8 |
| Dyssodia papposa | (Vent.) Hitchc. | Asteraceae | 8 |
| Dyssodia tagetiflora | Lag. | Asteraceae | 8 |
| Ebenopsis ebano | (Berland.) Barneby & J.W.Grimes | Fabaceae | 8 |
| Echeandia flavescens | (Schult. & Schult.f.) Cruden | Asparagaceae | 8 |
| Echeandia longipedicellata | Cruden | Asparagaceae | 8 |
| Echeandia mexicana | Cruden | Asparagaceae | 8 |
| Echeandia nana | (Baker) Cruden | Asparagaceae | 8 |
| Echeandia scabrella | (Benth.) Cruden | Asparagaceae | 8 |
| Echeveria agavoides | Lem. | Crassulaceae | 8 |
| Echeveria bifida | Schltdl. | Crassulaceae | 8 |
| Echeveria cuspidata | Rose | Crassulaceae | 8 |
| Echeveria fulgens | Lem. | Crassulaceae | 8 |
| Echeveria gibbiflora | DC. | Crassulaceae | 8 |
| Echeveria mucronata | Schltdl. | Crassulaceae | 8 |
| Echeveria rosea | Lindl. | Crassulaceae | 8 |
| Echeveria secunda | Booth ex Lindl. | Crassulaceae | 8 |
| Echeveria strictiflora | A.Gray | Crassulaceae | 8 |
| Echeveria subrigida | Rose | Crassulaceae | 8 |
| Echinocactus platyacanthus | Link & Otto | Cactaceae | 8 |
| Echinocereus berlandieri | (Engelm.) Haage | Cactaceae | 8 |
| Echinocereus coccineus | Engelm. | Cactaceae | 8 |
| Echinocereus engelmannii | (Parry ex Engelm.) Lem. | Cactaceae | 8 |
| Echinocereus fendleri | (Engelm.) Sencke ex J.N.Haage | Cactaceae | 8 |
| Echinocereus polyacanthus | Engelm. | Cactaceae | 8 |
| Echinocereus salm-dyckianus | Scheer | Cactaceae | 8 |
| Echinocereus santaritensis | W.Blum & Rutow | Cactaceae | 8 |
| Echinochloa walteri | (Pursh) A.Heller | Poaceae | 8 |
| Echinodorus berteroi | (Spreng.) Fassett | Alismataceae | 8 |
| Echinopepon wrightii | (A.Gray) S.Watson | Cucurbitaceae | 8 |
| Echites panduratus | A.DC. | Apocynaceae | 8 |
| Eclipta prostrata | (L.) L. | Asteraceae | 8 |
| Ehretia anacua | (Terán & Berland.) I.M.Johnst. | Ehretiaceae | 8 |
| Ehretia latifolia | Loisel. | Ehretiaceae | 8 |
| Ehretia tinifolia | L. | Ehretiaceae | 8 |
| Elaeodendron xylocarpum | (Vent.) DC. | Celastraceae | 8 |
| Elaphoglossum paleaceum | (Hook. & Grev.) Sledge | Dryopteridaceae | 8 |
| Elaphoglossum peltatum | (Sw.) Urb. | Dryopteridaceae | 8 |
| Elatine brachysperma | A.Gray | Elatinaceae | 8 |
| Electranthera mutica | (DC.) Mesfin, D.J.Crawford & Pruski | Asteraceae | 8 |
| Eleocharis acicularis | (L.) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis cellulosa | Torr. | Cyperaceae | 8 |
| Eleocharis elegans | (Kunth) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis geniculata | (L.) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis interstincta | (Vahl) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis macrostachya | Britton | Cyperaceae | 8 |
| Eleocharis montana | (Kunth) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis montevidensis | Kunth | Cyperaceae | 8 |
| Eleocharis palustris | (L.) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis quadrangulata | (Michx.) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis rostellata | (Torr.) Torr. | Cyperaceae | 8 |
| Elephantopus mollis | Kunth | Asteraceae | 8 |
| Elleanthus capitatus | (Poepp. & Endl.) Rchb.f. | Orchidaceae | 8 |
| Elymus canadensis | L. | Poaceae | 8 |
| Elymus elymoides | (Raf.) Swezey | Poaceae | 8 |
| Elymus interruptus | Buckley | Poaceae | 8 |
| Elymus longifolius | (J.G.Sm.) Gould | Poaceae | 8 |
| Elymus riparius | Wiegand | Poaceae | 8 |
| Elymus smithii | (Rydb.) Gould | Poaceae | 8 |
| Elymus violaceus | (Hornem.) J.Feilberg | Poaceae | 8 |
| Elytraria bromoides | Oerst. | Acanthaceae | 8 |
| Elytraria imbricata | (Vahl) Pers. | Acanthaceae | 8 |
| Encelia farinosa | A.Gray ex Torr. | Asteraceae | 8 |
| Encelia frutescens | A.Gray | Asteraceae | 8 |
| Encyclia parviflora | (Regel) Withner | Orchidaceae | 8 |
| Engelmannia peristenia | (Raf.) Goodman & C.A.Lawson | Asteraceae | 8 |
| Enneapogon desvauxii | P.Beauv. | Poaceae | 8 |
| Enterolobium cyclocarpum | (Jacq.) Griseb. | Fabaceae | 8 |
| Ephedra antisyphilitica | Berland. ex C.A.Mey. | Ephedraceae | 8 |
| Ephedra aspera | Engelm. ex S.Watson | Ephedraceae | 8 |
| Ephedra compacta | Rose | Ephedraceae | 8 |
| Ephedra pedunculata | Engelm. ex S.Watson | Ephedraceae | 8 |
| Ephedra torreyana | S.Watson | Ephedraceae | 8 |
| Ephedra trifurca | Torr. ex S.Watson | Ephedraceae | 8 |
| Epidendrum cardiophorum | Schltr. | Orchidaceae | 8 |
| Epidendrum ciliare | L. | Orchidaceae | 8 |
| Epidendrum conopseum | R.Br. | Orchidaceae | 8 |
| Epidendrum nocturnum | Jacq. | Orchidaceae | 8 |
| Epifagus virginiana | (L.) Barton | Orobanchaceae | 8 |
| Epilobium angustifolium | L. | Onagraceae | 8 |
| Epilobium canum | (Greene) P.H.Raven | Onagraceae | 8 |
| Epilobium ciliatum | Raf. | Onagraceae | 8 |
| Epilobium denticulatum | Ruiz & Pav. | Onagraceae | 8 |
| Epipactis gigantea | Douglas | Orchidaceae | 8 |
| Epithelantha bokei | L.D.Benson | Cactaceae | 8 |
| Epithelantha greggii | (Engelm.) Orcutt | Cactaceae | 8 |
| Epithelantha micromeris | (Engelm.) F.A.C.Weber ex Britton & Rose | Cactaceae | 8 |
| Epithelantha pachyrhiza | (W.T.Marshall) Backeb. | Cactaceae | 8 |
| Epithelantha potosina | (D.Donati & Zanov.) D.Aquino & S.Arias | Cactaceae | 8 |
| Epithelantha spinosior | C.Schmoll | Cactaceae | 8 |
| Epixiphium wislizeni | (Engelm. ex A.Gray) Munz | Plantaginaceae | 8 |
| Equisetum hyemale | L. | Equisetaceae | 8 |
| Equisetum laevigatum | A.Braun | Equisetaceae | 8 |
| Equisetum myriochaetum | Schltdl. & Cham. | Equisetaceae | 8 |
| Eragrostis curtipedicellata | Buckley | Poaceae | 8 |
| Eragrostis elliottii | (Elliott) S.Watson | Poaceae | 8 |
| Eragrostis hirsuta | (Michx.) Nees | Poaceae | 8 |
| Eragrostis hypnoides | (Lam.) Britton, Sterns & Poggenb. | Poaceae | 8 |
| Eragrostis intermedia | Hitchc. | Poaceae | 8 |
| Eragrostis pectinacea | (Michx.) Nees | Poaceae | 8 |
| Eragrostis reptans | (Michx.) Nees | Poaceae | 8 |
| Eragrostis secundiflora | J.Presl | Poaceae | 8 |
| Eragrostis sessilispica | Buckley | Poaceae | 8 |
| Eragrostis spectabilis | (Pursh) Steud. | Poaceae | 8 |
| Erblichia odorata | Seem. | Passifloraceae | 8 |
| Erechtites hieraciifolius | (L.) Raf. ex DC. | Asteraceae | 8 |
| Eremalche exilis | (A.Gray) Greene | Malvaceae | 8 |
| Eremosis leiocarpa | (DC.) Gleason | Asteraceae | 8 |
| Eremosis triflosculosa | (Kunth) Gleason | Asteraceae | 8 |
| Eremothera chamaenerioides | (A.Gray) W.L.Wagner & Hoch | Onagraceae | 8 |
| Eriastrum diffusum | (A.Gray) H.Mason | Polemoniaceae | 8 |
| Ericameria laricifolia | (A.Gray) Shinners | Asteraceae | 8 |
| Erigeron bellidiastrum | Nutt. | Asteraceae | 8 |
| Erigeron bonariensis | L. | Asteraceae | 8 |
| Erigeron canadensis | L. | Asteraceae | 8 |
| Erigeron divergens | Torr. & A.Gray | Asteraceae | 8 |
| Erigeron flagellaris | A.Gray | Asteraceae | 8 |
| Erigeron floribundus | (Kunth) Sch.Bip. | Asteraceae | 8 |
| Erigeron galeottii | (A.Gray ex Hemsl.) Greene | Asteraceae | 8 |
| Erigeron karvinskianus | DC. | Asteraceae | 8 |
| Erigeron longipes | DC. | Asteraceae | 8 |
| Erigeron modestus | A.Gray | Asteraceae | 8 |
| Erigeron neomexicanus | A.Gray | Asteraceae | 8 |
| Erigeron oreophilus | Greenm. | Asteraceae | 8 |
| Erigeron procumbens | (Mill.) G.L.Nesom | Asteraceae | 8 |
| Erigeron pubescens | Kunth | Asteraceae | 8 |
| Erigeron tracyi | Greene | Asteraceae | 8 |
| Erigeron variifolius | S.F.Blake | Asteraceae | 8 |
| Erigeron wislizeni | (A.Gray) Greene | Asteraceae | 8 |
| Eriochloa contracta | Hitchc. | Poaceae | 8 |
| Eriochloa sericea | (Scheele) Munro ex Vasey | Poaceae | 8 |
| Eriocoma arida | (M.E.Jones) Romasch. | Poaceae | 8 |
| Eriocoma hymenoides | (Roem. & Schult.) Rydb. | Poaceae | 8 |
| Eriocoma occidentalis | (Thurb. ex S.Watson) Romasch. | Poaceae | 8 |
| Eriocoma parishii | (Vasey) Romasch. | Poaceae | 8 |
| Eriogonum abertianum | Torr. | Polygonaceae | 8 |
| Eriogonum alatum | Torr. | Polygonaceae | 8 |
| Eriogonum annuum | Nutt. | Polygonaceae | 8 |
| Eriogonum greggii | Torr. & A.Gray | Polygonaceae | 8 |
| Eriogonum hemipterum | (Torr. & A.Gray) Torr. ex S.Stokes | Polygonaceae | 8 |
| Eriogonum inflatum | Torr. & Frém. | Polygonaceae | 8 |
| Eriogonum jamesii | Benth. | Polygonaceae | 8 |
| Eriogonum lonchophyllum | Torr. & A.Gray | Polygonaceae | 8 |
| Eriogonum polycladon | Benth. | Polygonaceae | 8 |
| Eriogonum rotundifolium | Benth. | Polygonaceae | 8 |
| Eriogonum tenellum | Torr. | Polygonaceae | 8 |
| Eriogonum wrightii | Torr. ex Benth. | Polygonaceae | 8 |
| Erioneuron avenaceum | (Kunth) Tateoka | Poaceae | 8 |
| Erioneuron pilosum | (Buckley) Nash | Poaceae | 8 |
| Erodium texanum | A.Gray | Geraniaceae | 8 |
| Eryngium carlinae | F.Delaroche | Apiaceae | 8 |
| Eryngium foetidum | L. | Apiaceae | 8 |
| Eryngium heterophyllum | Engelm. | Apiaceae | 8 |
| Eryngium lemmonii | J.M.Coult. & Rose | Apiaceae | 8 |
| Eryngium nasturtiifolium | F.Delaroche | Apiaceae | 8 |
| Erysimum asperum | (Nutt.) DC. | Brassicaceae | 8 |
| Erythranthe cordata | (Greene) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe floribunda | (Lindl.) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe geyeri | (Torr.) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe glabrata | (Kunth) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe guttata | (DC.) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe inamoena | (Greene) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe unimaculata | (Pennell) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe verbenacea | (Greene) G.L.Nesom & N.S.Fraga | Phrymaceae | 8 |
| Erythrina americana | Mill. | Fabaceae | 8 |
| Erythrina breviflora | Moc. & Sessé ex DC. | Fabaceae | 8 |
| Erythrina flabelliformis | Kearney | Fabaceae | 8 |
| Erythrina herbacea | L. | Fabaceae | 8 |
| Erythrina lanata | Rose | Fabaceae | 8 |
| Erythrina nigrorosea | (Krukoff & Barneby) G.L.Nesom | Fabaceae | 8 |
| Erythrostemon caudatus | (A.Gray) Gagnon & G.P.Lewis | Fabaceae | 8 |
| Erythrostemon mexicanus | (Rose) Gagnon & G.P.Lewis | Fabaceae | 8 |
| Erythrostemon palmeri | (S.Watson) Gagnon & G.P.Lewis | Fabaceae | 8 |
| Erythrostemon phyllanthoides | (Standl.) Gagnon & G.P.Lewis | Fabaceae | 8 |
| Erythroxylum areolatum | L. | Erythroxylaceae | 8 |
| Erythroxylum havanense | Jacq. | Erythroxylaceae | 8 |
| Erythroxylum mexicanum | Kunth | Erythroxylaceae | 8 |
| Erythroxylum rotundifolium | Lunan | Erythroxylaceae | 8 |
| Eschscholzia californica | Cham. | Papaveraceae | 8 |
| Escobedia grandiflora | (L.f.) Kuntze | Orobanchaceae | 8 |
| Eucnide bartonioides | Zucc. | Loasaceae | 8 |
| Eucnide hirta | (Pav. ex G.Don) H.J.Thomps. & W.R.Ernst | Loasaceae | 8 |
| Eucnide lobata | (Hook.) A.Gray | Loasaceae | 8 |
| Eugenia acapulcensis | Steud. | Myrtaceae | 8 |
| Eugenia axillaris | (Sw.) Willd. | Myrtaceae | 8 |
| Eugenia capuli | (Schltdl. & Cham.) Hook. & Arn. | Myrtaceae | 8 |
| Eumachia microdon | (DC.) Delprete & J.H.Kirkbr. | Rubiaceae | 8 |
| Eupatorium serotinum | Michx. | Asteraceae | 8 |
| Euphorbia acuta | Engelm. | Euphorbiaceae | 8 |
| Euphorbia albomarginata | Torr. & A.Gray | Euphorbiaceae | 8 |
| Euphorbia angusta | Engelm. | Euphorbiaceae | 8 |
| Euphorbia antisyphilitica | Zucc. | Euphorbiaceae | 8 |
| Euphorbia anychioides | Boiss. | Euphorbiaceae | 8 |
| Euphorbia ariensis | Kunth | Euphorbiaceae | 8 |
| Euphorbia arizonica | Engelm. | Euphorbiaceae | 8 |
| Euphorbia astyla | Engelm. ex Boiss. | Euphorbiaceae | 8 |
| Euphorbia berteroana | Balb. ex Spreng. | Euphorbiaceae | 8 |
| Euphorbia bifurcata | Engelm. | Euphorbiaceae | 8 |
| Euphorbia bombensis | Jacq. | Euphorbiaceae | 8 |
| Euphorbia brachycera | Engelm. | Euphorbiaceae | 8 |
| Euphorbia californica | Benth. | Euphorbiaceae | 8 |
| Euphorbia capitellata | Engelm. | Euphorbiaceae | 8 |
| Euphorbia carunculata | Waterf. | Euphorbiaceae | 8 |
| Euphorbia chaetocalyx | (Boiss.) Tidestr. | Euphorbiaceae | 8 |
| Euphorbia chamaesula | Boiss. | Euphorbiaceae | 8 |
| Euphorbia cinerascens | Engelm. | Euphorbiaceae | 8 |
| Euphorbia colletioides | Benth. | Euphorbiaceae | 8 |
| Euphorbia cotinifolia | L. | Euphorbiaceae | 8 |
| Euphorbia cuphosperma | (Engelm.) Boiss. | Euphorbiaceae | 8 |
| Euphorbia davidii | Subils | Euphorbiaceae | 8 |
| Euphorbia dentata | Michx. | Euphorbiaceae | 8 |
| Euphorbia eriantha | Benth. | Euphorbiaceae | 8 |
| Euphorbia exstipulata | Engelm. | Euphorbiaceae | 8 |
| Euphorbia fendleri | Torr. & A.Gray | Euphorbiaceae | 8 |
| Euphorbia florida | Engelm. | Euphorbiaceae | 8 |
| Euphorbia geyeri | Engelm. | Euphorbiaceae | 8 |
| Euphorbia glyptosperma | Engelm. | Euphorbiaceae | 8 |
| Euphorbia golondrina | L.C.Wheeler | Euphorbiaceae | 8 |
| Euphorbia gracillima | S.Watson | Euphorbiaceae | 8 |
| Euphorbia graminea | Jacq. | Euphorbiaceae | 8 |
| Euphorbia helleri | Millsp. | Euphorbiaceae | 8 |
| Euphorbia heterophylla | L. | Euphorbiaceae | 8 |
| Euphorbia hirta | L. | Euphorbiaceae | 8 |
| Euphorbia hypericifolia | L. | Euphorbiaceae | 8 |
| Euphorbia hyssopifolia | L. | Euphorbiaceae | 8 |
| Euphorbia indivisa | (Engelm.) Tidestr. | Euphorbiaceae | 8 |
| Euphorbia jejuna | M.C.Johnst. & Warnock | Euphorbiaceae | 8 |
| Euphorbia laredana | Millsp. | Euphorbiaceae | 8 |
| Euphorbia lasiocarpa | Klotzsch | Euphorbiaceae | 8 |
| Euphorbia macropus | (Klotzsch & Garcke) Boiss. | Euphorbiaceae | 8 |
| Euphorbia maculata | L. | Euphorbiaceae | 8 |
| Euphorbia marginata | Pursh | Euphorbiaceae | 8 |
| Euphorbia mendezii | Boiss. | Euphorbiaceae | 8 |
| Euphorbia micromera | Boiss. | Euphorbiaceae | 8 |
| Euphorbia nutans | Lag. | Euphorbiaceae | 8 |
| Euphorbia ophthalmica | Pers. | Euphorbiaceae | 8 |
| Euphorbia parryi | Engelm. | Euphorbiaceae | 8 |
| Euphorbia prostrata | Aiton | Euphorbiaceae | 8 |
| Euphorbia pulcherrima | Willd. ex Klotzsch | Euphorbiaceae | 8 |
| Euphorbia radians | Benth. | Euphorbiaceae | 8 |
| Euphorbia revoluta | Engelm. | Euphorbiaceae | 8 |
| Euphorbia schiedeana | (Klotzsch & Garcke) Mayfield ex C.Nelson | Euphorbiaceae | 8 |
| Euphorbia schlechtendalii | Boiss. | Euphorbiaceae | 8 |
| Euphorbia serpens | Kunth | Euphorbiaceae | 8 |
| Euphorbia serpillifolia | Pers. | Euphorbiaceae | 8 |
| Euphorbia serrula | Engelm. | Euphorbiaceae | 8 |
| Euphorbia setiloba | Engelm. | Euphorbiaceae | 8 |
| Euphorbia simulans | (L.C.Wheeler) Warnock & M.C.Johnst. | Euphorbiaceae | 8 |
| Euphorbia spathulata | Lam. | Euphorbiaceae | 8 |
| Euphorbia spellenbergiana | Mayfield & V.W.Steinm. | Euphorbiaceae | 8 |
| Euphorbia stictospora | Engelm. | Euphorbiaceae | 8 |
| Euphorbia strigosa | Hook. & Arn. | Euphorbiaceae | 8 |
| Euphorbia thymifolia | L. | Euphorbiaceae | 8 |
| Euphorbia tithymaloides | L. | Euphorbiaceae | 8 |
| Euphorbia triligulata | (L.C.Wheeler) A.M.Powell | Euphorbiaceae | 8 |
| Euphorbia tubadenia | Mayfield ex Ya Yang | Euphorbiaceae | 8 |
| Euphorbia velleriflora | (Klotzsch & Garcke) Boiss. | Euphorbiaceae | 8 |
| Euphorbia vermiculata | Raf. | Euphorbiaceae | 8 |
| Euphorbia villifera | Scheele | Euphorbiaceae | 8 |
| Euphrosyne dealbata | (A.Gray) Panero | Asteraceae | 8 |
| Euploca confertifolia | (Torr.) Feuillet & Halse | Heliotropiaceae | 8 |
| Euploca convolvulacea | Nutt. | Heliotropiaceae | 8 |
| Euploca foliosissima | (J.F.Macbr.) J.I.M.Melo | Heliotropiaceae | 8 |
| Euploca greggii | (Torr.) Halse & Feuillet | Heliotropiaceae | 8 |
| Euploca procumbens | (Mill.) Diane & Hilger | Heliotropiaceae | 8 |
| Euploca racemosa | Rose & Standl. | Heliotropiaceae | 8 |
| Euploca torreyi | (I.M.Johnst.) Halse & Feuillet | Heliotropiaceae | 8 |
| Eustachys petraea | (Sw.) Desv. | Poaceae | 8 |
| Eustoma exaltatum | (L.) Salisb. ex G.Don | Gentianaceae | 8 |
| Eustoma russellianum | (Hook.) G.Don | Gentianaceae | 8 |
| Eutetras pringlei | Greenm. | Asteraceae | 8 |
| Eutrema salsugineum | (Pall.) Al-Shehbaz & Warwick | Brassicaceae | 8 |
| Evolvulus alsinoides | (L.) L. | Convolvulaceae | 8 |
| Evolvulus arizonicus | A.Gray | Convolvulaceae | 8 |
| Evolvulus nummularius | (L.) L. | Convolvulaceae | 8 |
| Evolvulus nuttallianus | Schult. | Convolvulaceae | 8 |
| Evolvulus prostratus | B.L.Rob. | Convolvulaceae | 8 |
| Evolvulus sericeus | Sw. | Convolvulaceae | 8 |
| Exostema caribaeum | (Jacq.) Schult. | Rubiaceae | 8 |
| Exothea paniculata | Radlk. | Sapindaceae | 8 |
| Eysenhardtia orthocarpa | (A.Gray) S.Watson | Fabaceae | 8 |
| Eysenhardtia polystachya | (Ortega) Sarg. | Fabaceae | 8 |
| Eysenhardtia texana | Scheele | Fabaceae | 8 |
| Fagus grandifolia | Ehrh. | Fagaceae | 8 |
| Fallugia paradoxa | (D.Don ex Tilloch & Taylor) Endl. ex Torr. | Rosaceae | 8 |
| Faramea occidentalis | (L.) A.Rich. | Rubiaceae | 8 |
| Fendlera rupicola | A.Gray | Hydrangeaceae | 8 |
| Fendlerella lasiopetala | Standl. | Hydrangeaceae | 8 |
| Fendlerella utahensis | (S.Watson) A.Heller | Hydrangeaceae | 8 |
| Ferocactus echidne | (DC.) Britton & Rose | Cactaceae | 8 |
| Ferocactus emoryi | (Engelm.) Orcutt | Cactaceae | 8 |
| Ferocactus glaucescens | (DC.) Britton & Rose | Cactaceae | 8 |
| Ferocactus hamatacanthus | (Muehlenpf.) Britton & Rose | Cactaceae | 8 |
| Ferocactus herrerae | J.G.Ortega | Cactaceae | 8 |
| Ferocactus histrix | (DC.) G.E.Linds. | Cactaceae | 8 |
| Ferocactus macrodiscus | (Mart.) Britton & Rose | Cactaceae | 8 |
| Ferocactus mathssonii | (Berge ex K.Schum.) N.P.Taylor | Cactaceae | 8 |
| Ferocactus piliferus | (Lem.) G.Unger | Cactaceae | 8 |
| Ferocactus uncinatus | (Galeotti ex Pfeiff.) Britton & Rose | Cactaceae | 8 |
| Ferocactus wislizeni | (Engelm.) Britton & Rose | Cactaceae | 8 |
| Festuca arizonica | Vasey | Poaceae | 8 |
| Festuca rubra | L. | Poaceae | 8 |
| Festuca subverticillata | (Pers.) E.B.Alexeev | Poaceae | 8 |
| Ficus americana | Aubl. | Moraceae | 8 |
| Ficus aurea | Nutt. | Moraceae | 8 |
| Ficus citrifolia | Mill. | Moraceae | 8 |
| Ficus cotinifolia | Kunth | Moraceae | 8 |
| Ficus crocata | Mart. ex Miq. | Moraceae | 8 |
| Ficus insipida | Willd. | Moraceae | 8 |
| Ficus maxima | Mill. | Moraceae | 8 |
| Ficus obtusifolia | Kunth | Moraceae | 8 |
| Ficus pertusa | L.f. | Moraceae | 8 |
| Ficus petiolaris | Kunth | Moraceae | 8 |
| Fimbristylis autumnalis | (L.) Roem. & Schult. | Cyperaceae | 8 |
| Fimbristylis caroliniana | (Lam.) Fernald | Cyperaceae | 8 |
| Fimbristylis complanata | (Retz.) Link | Cyperaceae | 8 |
| Fimbristylis cymosa | R.Br. | Cyperaceae | 8 |
| Fimbristylis dichotoma | (L.) Vahl | Cyperaceae | 8 |
| Fimbristylis littoralis | Gaudich. | Cyperaceae | 8 |
| Fimbristylis spadicea | (L.) Vahl | Cyperaceae | 8 |
| Fimbristylis thermalis | S.Watson | Cyperaceae | 8 |
| Fimbristylis vahlii | (Lam.) Link | Cyperaceae | 8 |
| Flaveria trinervia | (Spreng.) C.Mohr | Asteraceae | 8 |
| Fleischmannia incarnata | (Walter) R.M.King & H.Rob. | Asteraceae | 8 |
| Fleischmannia pycnocephala | (Less.) R.M.King & H.Rob. | Asteraceae | 8 |
| Fleischmanniopsis leucocephala | (Benth.) R.M.King & H.Rob. | Asteraceae | 8 |
| Florestina pedata | Cass. | Asteraceae | 8 |
| Florestina tripteris | DC. | Asteraceae | 8 |
| Flourensia cernua | DC. | Asteraceae | 8 |
| Forestiera angustifolia | Torr. | Oleaceae | 8 |
| Forestiera phillyreoides | (Benth.) Torr. | Oleaceae | 8 |
| Forestiera pubescens | Nutt. | Oleaceae | 8 |
| Forestiera reticulata | Torr. | Oleaceae | 8 |
| Fosterella micrantha | (Lindl.) L.B.Sm. | Bromeliaceae | 8 |
| Fouquieria macdougalii | Nash | Fouquieriaceae | 8 |
| Fouquieria splendens | Engelm. | Fouquieriaceae | 8 |
| Fragaria vesca | L. | Rosaceae | 8 |
| Fragaria virginiana | Mill. | Rosaceae | 8 |
| Frangula californica | (Eschsch.) A.Gray | Rhamnaceae | 8 |
| Frangula capreifolia | (Schltdl.) Grubov | Rhamnaceae | 8 |
| Frangula caroliniana | (Walter) A.Gray | Rhamnaceae | 8 |
| Frangula mucronata | (Schltdl.) Grubov | Rhamnaceae | 8 |
| Frangula purshiana | (DC.) A.Gray ex J.G.Cooper | Rhamnaceae | 8 |
| Frankenia johnstonii | Correll | Frankeniaceae | 8 |
| Frankenia salina | (Molina) I.M.Johnst. | Frankeniaceae | 8 |
| Frasera speciosa | Douglas ex Griseb. | Gentianaceae | 8 |
| Fraxinus albicans | Buckley | Oleaceae | 8 |
| Fraxinus americana | L. | Oleaceae | 8 |
| Fraxinus berlandieriana | A.DC. | Oleaceae | 8 |
| Fraxinus cuspidata | Torr. | Oleaceae | 8 |
| Fraxinus greggii | A.Gray | Oleaceae | 8 |
| Fraxinus papillosa | Lingelsh. | Oleaceae | 8 |
| Fraxinus purpusii | Brandegee | Oleaceae | 8 |
| Fraxinus uhdei | (Wenz.) Lingelsh. | Oleaceae | 8 |
| Fraxinus velutina | Torr. | Oleaceae | 8 |
| Froelichia arizonica | Thornber ex Standl. | Amaranthaceae | 8 |
| Froelichia floridana | (Nutt.) Moq. | Amaranthaceae | 8 |
| Froelichia gracilis | (Hook.) Moq. | Amaranthaceae | 8 |
| Fuchsia arborescens | Sims | Onagraceae | 8 |
| Fuchsia microphylla | Kunth | Onagraceae | 8 |
| Fuertesimalva limensis | (L.) Fryxell | Malvaceae | 8 |
| Fuirena simplex | Vahl | Cyperaceae | 8 |
| Funastrum angustifolium | (Pers.) Liede & Meve | Apocynaceae | 8 |
| Funastrum clausum | (Jacq.) Schltr. | Apocynaceae | 8 |
| Funastrum crispum | (Benth.) Schltr. | Apocynaceae | 8 |
| Funastrum cynanchoides | (Decne.) Schltr. | Apocynaceae | 8 |
| Funastrum elegans | (Decne.) Schltr. | Apocynaceae | 8 |
| Funastrum heterophyllum | (Engelm. ex Torr.) Standl. | Apocynaceae | 8 |
| Funastrum pannosum | (Decne.) Schltr. | Apocynaceae | 8 |
| Funastrum torreyi | (A.Gray) Schltr. | Apocynaceae | 8 |
| Gaga kaulfussii | (Kunze) Fay W.Li & Windham | Pteridaceae | 8 |
| Gaillardia comosa | A.Gray | Asteraceae | 8 |
| Gaillardia mexicana | A.Gray | Asteraceae | 8 |
| Gaillardia multiceps | Greene | Asteraceae | 8 |
| Gaillardia pinnatifida | Torr. | Asteraceae | 8 |
| Gaillardia pulchella | Foug. | Asteraceae | 8 |
| Gaillardia suavis | (A.Gray & Engelm.) Britton & Rusby | Asteraceae | 8 |
| Galactia canescens | Benth. | Fabaceae | 8 |
| Galactia striata | (Jacq.) Urb. | Fabaceae | 8 |
| Galactia texana | (Scheele) A.Gray | Fabaceae | 8 |
| Galactia wrightii | A.Gray | Fabaceae | 8 |
| Galeottiella sarcoglossa | (A.Rich. & Galeotti) Schltr. | Orchidaceae | 8 |
| Galianthe brasiliensis | (Spreng.) E.L.Cabral & Bacigalupo | Rubiaceae | 8 |
| Galinsoga parviflora | Cav. | Asteraceae | 8 |
| Galinsoga quadriradiata | Ruiz & Pav. | Asteraceae | 8 |
| Galium hypocarpium | (L.) Endl. ex Griseb. | Rubiaceae | 8 |
| Galium mexicanum | Kunth | Rubiaceae | 8 |
| Galium proliferum | A.Gray | Rubiaceae | 8 |
| Galium trifidum | L. | Rubiaceae | 8 |
| Galium triflorum | Michx. | Rubiaceae | 8 |
| Galium wrightii | A.Gray | Rubiaceae | 8 |
| Galphimia angustifolia | Benth. | Malpighiaceae | 8 |
| Galphimia glauca | Cav. | Malpighiaceae | 8 |
| Galphimia gracilis | Bartl. | Malpighiaceae | 8 |
| Gamochaeta americana | (Mill.) Wedd. | Asteraceae | 8 |
| Gamochaeta pensylvanica | (Willd.) Cabrera | Asteraceae | 8 |
| Gamochaeta purpurea | (L.) Cabrera | Asteraceae | 8 |
| Gamochaeta stagnalis | (I.M.Johnst.) Anderb. | Asteraceae | 8 |
| Garrya goldmanii | Wooton & Standl. | Garryaceae | 8 |
| Garrya laurifolia | Benth. | Garryaceae | 8 |
| Garrya lindheimeri | Torr. | Garryaceae | 8 |
| Garrya ovata | Benth. | Garryaceae | 8 |
| Garrya wrightii | Torr. | Garryaceae | 8 |
| Gaultheria acuminata | Schltdl. & Cham. | Ericaceae | 8 |
| Gaultheria erecta | Vent. | Ericaceae | 8 |
| Gaultheria myrsinoides | Kunth | Ericaceae | 8 |
| Gelsemium sempervirens | (L.) J.St.-Hil. | Gelsemiaceae | 8 |
| Genistidium dumosum | I.M.Johnst. | Fabaceae | 8 |
| Gentiana autumnalis | L. | Gentianaceae | 8 |
| Gentiana bicuspidata | (G.Don) Briq. | Gentianaceae | 8 |
| Gentiana hooperi | J.S.Pringle | Gentianaceae | 8 |
| Gentiana spathacea | Kunth | Gentianaceae | 8 |
| Geranium caespitosum | E.James | Geraniaceae | 8 |
| Geranium carolinianum | L. | Geraniaceae | 8 |
| Geranium potentillifolium | DC. | Geraniaceae | 8 |
| Geranium seemannii | Peyr. | Geraniaceae | 8 |
| Geranium wislizeni | S.Watson | Geraniaceae | 8 |
| Geum aleppicum | Jacq. | Rosaceae | 8 |
| Gibasis geniculata | (Jacq.) Rohweder | Commelinaceae | 8 |
| Gilia mexicana | A.D.Grant & V.E.Grant | Polemoniaceae | 8 |
| Giliastrum acerosum | (A.Gray) Rydb. | Polemoniaceae | 8 |
| Giliastrum incisum | (Benth.) J.M.Porter | Polemoniaceae | 8 |
| Giliastrum rigidulum | Rydb. | Polemoniaceae | 8 |
| Giliastrum stewartii | (I.M.Johnst.) J.M.Porter | Polemoniaceae | 8 |
| Gleditsia aquatica | Marshall | Fabaceae | 8 |
| Gleditsia triacanthos | L. | Fabaceae | 8 |
| Gleichenella pectinata | (Willd.) Ching | Gleicheniaceae | 8 |
| Glinus radiatus | (Ruiz & Pav.) Rohrb. | Molluginaceae | 8 |
| Gliricidia sepium | (Jacq.) Kunth | Fabaceae | 8 |
| Glossopetalon spinescens | A.Gray | Crossosomataceae | 8 |
| Glyceria borealis | (Nash) Batch. | Poaceae | 8 |
| Glyceria elata | (Nash) M.E.Jones | Poaceae | 8 |
| Glyceria septentrionalis | Hitchc. | Poaceae | 8 |
| Glyceria striata | (Lam.) Hitchc. | Poaceae | 8 |
| Glycyrrhiza lepidota | Pursh | Fabaceae | 8 |
| Gnaphalium palustre | Nutt. | Asteraceae | 8 |
| Gomphrena caespitosa | Torr. | Amaranthaceae | 8 |
| Gomphrena globosa | L. | Amaranthaceae | 8 |
| Gomphrena lanuparonychioides | T. Ortuño & Borsch | Amaranthaceae | 8 |
| Gomphrena serrata | L. | Amaranthaceae | 8 |
| Gomphrena sonorae | Torr. ex Emory | Amaranthaceae | 8 |
| Gomphrena vermicularis | L. | Amaranthaceae | 8 |
| Gongora galeata | (Lindl. ex Bosse) Rchb.f. | Orchidaceae | 8 |
| Gonolobus barbatus | Kunth | Apocynaceae | 8 |
| Gonolobus erianthus | Decne. | Apocynaceae | 8 |
| Gonolobus grandiflorus | (Cav.) Schult. | Apocynaceae | 8 |
| Gonolobus naturalistae | M.G.Chávez, Pío-León & L.O.Alvarado | Apocynaceae | 8 |
| Gonolobus pectinatus | Brandegee | Apocynaceae | 8 |
| Gonolobus uniflorus | Kunth | Apocynaceae | 8 |
| Goodyera oblongifolia | Raf. | Orchidaceae | 8 |
| Goodyera striata | Rchb.f. | Orchidaceae | 8 |
| Gossypium aridum | (Rose & Standl.) Skovsted | Malvaceae | 8 |
| Gossypium hirsutum | L. | Malvaceae | 8 |
| Gossypium thurberi | Tod. | Malvaceae | 8 |
| Gouania lupuloides | (L.) Urb. | Rhamnaceae | 8 |
| Gouania rosei | Wiggins | Rhamnaceae | 8 |
| Govenia alba | A.Rich. & Galeotti | Orchidaceae | 8 |
| Govenia liliacea | (Lex.) Lindl. | Orchidaceae | 8 |
| Govenia superba | (Lex.) Lindl. | Orchidaceae | 8 |
| Graptopetalum pachyphyllum | Rose | Crassulaceae | 8 |
| Greenmaniella resinosa | W.M.Sharp | Asteraceae | 8 |
| Grindelia inuloides | Willd. | Asteraceae | 8 |
| Grindelia lanceolata | Nutt. | Asteraceae | 8 |
| Grindelia scabra | Greene | Asteraceae | 8 |
| Grindelia squarrosa | (Pursh) Dunal | Asteraceae | 8 |
| Grindelia subdecurrens | DC. | Asteraceae | 8 |
| Grona triflora | (L.) H.Ohashi & K.Ohashi | Fabaceae | 8 |
| Gronovia scandens | L. | Loasaceae | 8 |
| Grusonia aggeria | (Ralston & Hilsenb.) E.F.Anderson | Cactaceae | 8 |
| Grusonia bradtiana | (J.M.Coult.) Britton & Rose | Cactaceae | 8 |
| Grusonia bulbispina | (Engelm.) H.Rob. | Cactaceae | 8 |
| Grusonia emoryi | (Engelm.) Pinkava | Cactaceae | 8 |
| Grusonia grahamii | (Engelm.) H.Rob. | Cactaceae | 8 |
| Grusonia schottii | (Engelm.) H.Rob. | Cactaceae | 8 |
| Guaiacum coulteri | A.Gray | Zygophyllaceae | 8 |
| Guardiola platyphylla | A.Gray | Asteraceae | 8 |
| Guarianthe aurantiaca | (Bateman ex Lindl.) Dressler & W.E.Higgins | Orchidaceae | 8 |
| Guazuma ulmifolia | Lam. | Malvaceae | 8 |
| Guilleminea densa | (Humb. & Bonpl. ex Schult.) Moq. | Amaranthaceae | 8 |
| Gutierrezia conoidea | (Hemsl.) M.A.Lane | Asteraceae | 8 |
| Gutierrezia microcephala | (DC.) A.Gray | Asteraceae | 8 |
| Gutierrezia sarothrae | (Pursh) Britton & Rusby | Asteraceae | 8 |
| Gutierrezia sphaerocephala | A.Gray | Asteraceae | 8 |
| Gymnanthes lucida | Sw. | Euphorbiaceae | 8 |
| Gymnosiphon suaveolens | (H.Karst.) Urb. | Burmanniaceae | 8 |
| Gymnosperma glutinosum | (Spreng.) Less. | Asteraceae | 8 |
| Gynerium sagittatum | (Aubl.) P.Beauv. | Poaceae | 8 |
| Gyrandra tenuifolia | (M.Martens & Galeotti) G.Mans. | Gentianaceae | 8 |
| Gyrocarpus jatrophifolius | Domin | Hernandiaceae | 8 |
| Habenaria floribunda | Lindl. | Orchidaceae | 8 |
| Habenaria macroceratitis | Willd. | Orchidaceae | 8 |
| Habenaria repens | Nutt. | Orchidaceae | 8 |
| Habenaria trifida | Kunth | Orchidaceae | 8 |
| Habranthus longifolius | (Hemsl.) Flagg, G.Lom.Sm. & Meerow | Amaryllidaceae | 8 |
| Haematoxylum brasiletto | H.Karst. | Fabaceae | 8 |
| Halerpestes cymbalaria | Greene | Ranunculaceae | 8 |
| Halophila engelmannii | Asch. | Hydrocharitaceae | 8 |
| Hamamelis virginiana | L. | Hamamelidaceae | 8 |
| Hamelia patens | Jacq. | Rubiaceae | 8 |
| Hamelia xorullensis | Kunth | Rubiaceae | 8 |
| Handroanthus chrysanthus | (Jacq.) S.O.Grose | Bignoniaceae | 8 |
| Haplophyton crooksii | (L.D.Benson) L.D.Benson | Apocynaceae | 8 |
| Harpalyce arborescens | A.Gray | Fabaceae | 8 |
| Hauya elegans | Moc. & Sessé ex DC. | Onagraceae | 8 |
| Havardia pallens | (Benth.) Britton & Rose | Fabaceae | 8 |
| Hebecarpa barbeyana | (Chodat) J.R.Abbott | Polygalaceae | 8 |
| Hebecarpa macradenia | (A.Gray) J.R.Abbott | Polygalaceae | 8 |
| Hebecarpa obscura | (Benth.) J.R.Abbott | Polygalaceae | 8 |
| Hebecarpa ovatifolia | (A.Gray) J.R.Abbott | Polygalaceae | 8 |
| Hechtia glomerata | Zucc. | Bromeliaceae | 8 |
| Hechtia podantha | Mez | Bromeliaceae | 8 |
| Hechtia rosea | É.Morren ex Baker | Bromeliaceae | 8 |
| Hechtia texensis | S.Watson | Bromeliaceae | 8 |
| Hedeoma acinoides | Scheele | Lamiaceae | 8 |
| Hedeoma costata | A.Gray | Lamiaceae | 8 |
| Hedeoma drummondii | Benth. | Lamiaceae | 8 |
| Hedeoma hyssopifolia | A.Gray | Lamiaceae | 8 |
| Hedeoma nana | (Torr.) Briq. | Lamiaceae | 8 |
| Hedeoma oblongifolia | (A.Gray) A.Heller | Lamiaceae | 8 |
| Hedeoma palmeri | Hemsl. | Lamiaceae | 8 |
| Hedeoma plicata | Torr. | Lamiaceae | 8 |
| Hedosyne ambrosiifolia | (A.Gray) Strother | Asteraceae | 8 |
| Hedyosmum mexicanum | C.Cordem. | Chloranthaceae | 8 |
| Heimia salicifolia | Link | Lythraceae | 8 |
| Helenium amarum | (Raf.) H.Rock | Asteraceae | 8 |
| Helenium mexicanum | Kunth | Asteraceae | 8 |
| Helenium microcephalum | DC. | Asteraceae | 8 |
| Helenium thurberi | A.Gray | Asteraceae | 8 |
| Helianthella quinquenervis | (Hook.) A.Gray | Asteraceae | 8 |
| Helianthus annuus | L. | Asteraceae | 8 |
| Helianthus ciliaris | DC. | Asteraceae | 8 |
| Helianthus hirsutus | Raf. | Asteraceae | 8 |
| Helianthus laciniatus | A.Gray | Asteraceae | 8 |
| Helianthus maximiliani | Schrad. | Asteraceae | 8 |
| Helianthus niveus | (Benth.) Brandegee | Asteraceae | 8 |
| Helianthus petiolaris | Nutt. | Asteraceae | 8 |
| Heliconia latispatha | Benth. | Heliconiaceae | 8 |
| Heliconia schiedeana | Klotzsch | Heliconiaceae | 8 |
| Helicteres baruensis | Jacq. | Malvaceae | 8 |
| Helicteres guazumifolia | Kunth | Malvaceae | 8 |
| Helietta parvifolia | Benth. | Rutaceae | 8 |
| Heliocarpus americanus | L. | Malvaceae | 8 |
| Heliocarpus terebinthinaceus | (DC.) Hochr. | Malvaceae | 8 |
| Heliomeris longifolia | Cockerell | Asteraceae | 8 |
| Heliomeris multiflora | Nutt. | Asteraceae | 8 |
| Heliopsis annua | Hemsl. | Asteraceae | 8 |
| Heliopsis buphthalmoides | Dunal | Asteraceae | 8 |
| Heliopsis parvifolia | A.Gray | Asteraceae | 8 |
| Heliotropium angiospermum | Murray | Heliotropiaceae | 8 |
| Heliotropium curassavicum | L. | Heliotropiaceae | 8 |
| Heliotropium verdcourtii | Craven | Heliotropiaceae | 8 |
| Helosis cayennensis | (Sw.) Spreng. | Balanophoraceae | 8 |
| Hemichaena fruticosa | Benth. | Phrymaceae | 8 |
| Hemionitis palmata | L. | Pteridaceae | 8 |
| Hemiphylacus latifolius | S.Watson | Asparagaceae | 8 |
| Henrya insularis | Nees | Acanthaceae | 8 |
| Herissantia crispa | (L.) Brizicky | Malvaceae | 8 |
| Hermannia texana | A.Gray | Malvaceae | 8 |
| Hesperalbizia occidentalis | (Brandegee) Barneby & J.W.Grimes | Fabaceae | 8 |
| Hesperaloe funifera | (K.Koch) Trel. | Asparagaceae | 8 |
| Hesperaloe parviflora | (Torr.) J.M.Coult. | Asparagaceae | 8 |
| Hesperidanthus linearifolius | (A.Gray) Rydb. | Brassicaceae | 8 |
| Hesperocyparis arizonica | (Greene) Bartel | Cupressaceae | 8 |
| Hesperocyparis benthamii | (Endl.) Bartel | Cupressaceae | 8 |
| Hesperocyparis lusitanica | (Mill.) Bartel | Cupressaceae | 8 |
| Hesperostipa neomexicana | (Thurb.) Barkworth | Poaceae | 8 |
| Hesperostipa spartea | (Trin.) Barkworth | Poaceae | 8 |
| Heteranthera dubia | (Jacq.) MacMill. | Pontederiaceae | 8 |
| Heteranthera limosa | (Sw.) Willd. | Pontederiaceae | 8 |
| Heteranthera reniformis | Ruiz & Pav. | Pontederiaceae | 8 |
| Heterocentron elegans | (Schltdl.) Kuntze | Melastomataceae | 8 |
| Heterocentron subtriplinervium | (Link & Otto) A.Braun & C.D.Bouché | Melastomataceae | 8 |
| Heteropogon contortus | (L.) P.Beauv. ex Roem. & Schult. | Poaceae | 8 |
| Heteropogon melanocarpus | (Elliott) Benth. | Poaceae | 8 |
| Heteropterys brachiata | (L.) DC. | Malpighiaceae | 8 |
| Heterosperma pinnatum | Cav. | Asteraceae | 8 |
| Heterotheca fulcrata | (Greene) Shinners | Asteraceae | 8 |
| Heterotheca inuloides | Cass. | Asteraceae | 8 |
| Heterotheca mucronata | V.L.Harms ex B.L.Turner | Asteraceae | 8 |
| Heterotheca subaxillaris | (Lam.) Britton & Rusby | Asteraceae | 8 |
| Heterotheca viscida | (A.Gray) V.L.Harms | Asteraceae | 8 |
| Heuchera parvifolia | Nutt. ex Torr. & A.Gray | Saxifragaceae | 8 |
| Heuchera rubescens | Torr. | Saxifragaceae | 8 |
| Heuchera sanguinea | Engelm. | Saxifragaceae | 8 |
| Hexasepalum teres | (Walter) J.H.Kirkbr. | Rubiaceae | 8 |
| Hibiscus acicularis | Standl. | Malvaceae | 8 |
| Hibiscus coulteri | Harv. ex A.Gray | Malvaceae | 8 |
| Hibiscus denudatus | Benth. | Malvaceae | 8 |
| Hibiscus martianus | Zucc. | Malvaceae | 8 |
| Hibiscus phoeniceus | Jacq. | Malvaceae | 8 |
| Hibiscus poeppigii | Garcke | Malvaceae | 8 |
| Hibiscus tiliaceus | L. | Malvaceae | 8 |
| Hieracium abscissum | Less. | Asteraceae | 8 |
| Hieracium albiflorum | Hook. | Asteraceae | 8 |
| Hieracium fendleri | Sch.Bip. | Asteraceae | 8 |
| Hieracium gronovii | L. | Asteraceae | 8 |
| Hilaria belangeri | (Steud.) Nash | Poaceae | 8 |
| Hilaria cenchroides | Kunth | Poaceae | 8 |
| Hilaria mutica | (Buckley) Benth. | Poaceae | 8 |
| Hilaria rigida | (Thurb.) Benth. ex Scribn. | Poaceae | 8 |
| Hintonia latiflora | (Sessé & Moc. ex DC.) Bullock | Rubiaceae | 8 |
| Hippocratea volubilis | L. | Celastraceae | 8 |
| Hoffmannia excelsa | (Kunth) K.Schum. | Rubiaceae | 8 |
| Hoffmannseggia drepanocarpa | A.Gray | Fabaceae | 8 |
| Hoffmannseggia glauca | (Ortega) Eifert | Fabaceae | 8 |
| Hoffmannseggia oxycarpa | Benth. | Fabaceae | 8 |
| Holodiscus discolor | (Pursh) Maxim. | Rosaceae | 8 |
| Homalocephala parryi | (Engelm.) Vargas & Bárcenas | Cactaceae | 8 |
| Homalocephala texensis | (Hopffer) Britton & Rose | Cactaceae | 8 |
| Hopia obtusa | (Kunth) Zuloaga & Morrone | Poaceae | 8 |
| Hordeum jubatum | L. | Poaceae | 8 |
| Houstonia acerosa | (A.Gray) Benth. & Hook.f. | Rubiaceae | 8 |
| Houstonia humifusa | (Engelm. ex A.Gray) A.Gray | Rubiaceae | 8 |
| Houstonia rubra | Cav. | Rubiaceae | 8 |
| Houstonia wrightii | A.Gray | Rubiaceae | 8 |
| Humulus neomexicanus | (A.Nelson & Cockerell) Rydb. | Cannabaceae | 8 |
| Hunnemannia fumariifolia | Sweet | Papaveraceae | 8 |
| Hunzikeria texana | (Torr.) D'Arcy | Solanaceae | 8 |
| Huperzia serrata | (Thunb.) Trevis. | Lycopodiaceae | 8 |
| Hura polyandra | Baill. | Euphorbiaceae | 8 |
| Hybridella globosa | Cass. | Asteraceae | 8 |
| Hydrocotyle bonariensis | Comm. ex Lam. | Araliaceae | 8 |
| Hydrocotyle mexicana | Schltdl. & Cham. | Araliaceae | 8 |
| Hydrocotyle ranunculoides | L.f. | Araliaceae | 8 |
| Hydrocotyle umbellata | L. | Araliaceae | 8 |
| Hydrocotyle verticillata | Thunb. | Araliaceae | 8 |
| Hydrogalium claytonii | (Michx.) Kadereit & Schneew. | Rubiaceae | 8 |
| Hydrolea spinosa | L. | Hydroleaceae | 8 |
| Hylodesmum glutinosum | (Muhl. ex Willd.) H.Ohashi & R.R.Mill | Fabaceae | 8 |
| Hymenachne amplexicaulis | (Rudge) Nees | Poaceae | 8 |
| Hymenopappus artemisiifolius | DC. | Asteraceae | 8 |
| Hymenopappus flavescens | A.Gray | Asteraceae | 8 |
| Hymenopappus mexicanus | A.Gray | Asteraceae | 8 |
| Hymenopappus scabiosaeus | L'Hér. | Asteraceae | 8 |
| Hymenostephium cordatum | S.F.Blake | Asteraceae | 8 |
| Hymenothrix dissecta | (A.Gray) B.G.Baldwin | Asteraceae | 8 |
| Hymenothrix pedata | (A.Gray) B.G.Baldwin | Asteraceae | 8 |
| Hymenothrix wislizeni | A.Gray | Asteraceae | 8 |
| Hymenothrix wrightii | A.Gray | Asteraceae | 8 |
| Hymenoxys insignis | (A.Gray ex S.Watson) Cockerell | Asteraceae | 8 |
| Hymenoxys integrifolia | (Kunth) Bierner | Asteraceae | 8 |
| Hymenoxys odorata | DC. | Asteraceae | 8 |
| Hypericum hypericoides | (L.) Crantz | Hypericaceae | 8 |
| Hypericum mutilum | L. | Hypericaceae | 8 |
| Hypericum parvulum | Greene | Hypericaceae | 8 |
| Hypericum scouleri | Hook. | Hypericaceae | 8 |
| Hypericum silenoides | Juss. | Hypericaceae | 8 |
| Hypopitys monotropa | Crantz | Ericaceae | 8 |
| Hypoxis decumbens | L. | Hypoxidaceae | 8 |
| Hypoxis hirsuta | (L.) Coville | Hypoxidaceae | 8 |
| Hypoxis wrightii | (Baker) Brackett | Hypoxidaceae | 8 |
| Hyptis capitata | Jacq. | Lamiaceae | 8 |
| Ibervillea lindheimeri | (A.Gray) Greene | Cucurbitaceae | 8 |
| Ibervillea tenuisecta | (A.Gray) Small | Cucurbitaceae | 8 |
| Ichnanthus pallens | (Sw.) Munro ex Benth. | Poaceae | 8 |
| Ilex brandegeeana | Loes. | Aquifoliaceae | 8 |
| Ilex cassine | L. | Aquifoliaceae | 8 |
| Ilex decidua | Walter | Aquifoliaceae | 8 |
| Illicium floridanum | J.Ellis | Schisandraceae | 8 |
| Indigofera lindheimeriana | Scheele | Fabaceae | 8 |
| Indigofera miniata | Ortega | Fabaceae | 8 |
| Indigofera suffruticosa | Mill. | Fabaceae | 8 |
| Indigofera tinctoria | L. | Fabaceae | 8 |
| Inga oerstediana | Benth. | Fabaceae | 8 |
| Inga vera | Willd. | Fabaceae | 8 |
| Iochroma arborescens | (L.) J.M.H.Shaw | Solanaceae | 8 |
| Iostephane heterophylla | Benth. | Asteraceae | 8 |
| Ipomoea alba | L. | Convolvulaceae | 8 |
| Ipomoea anisomeres | B.L.Rob. & Bartlett | Convolvulaceae | 8 |
| Ipomoea arborescens | (Humb. & Bonpl. ex Willd.) G.Don | Convolvulaceae | 8 |
| Ipomoea aristolochiifolia | G.Don | Convolvulaceae | 8 |
| Ipomoea batatas | (L.) Lam. | Convolvulaceae | 8 |
| Ipomoea batatoides | Choisy | Convolvulaceae | 8 |
| Ipomoea bracteata | Cav. | Convolvulaceae | 8 |
| Ipomoea capillacea | (Kunth) G.Don | Convolvulaceae | 8 |
| Ipomoea cardiophylla | A.Gray | Convolvulaceae | 8 |
| Ipomoea carnea | Jacq. | Convolvulaceae | 8 |
| Ipomoea cholulensis | Kunth | Convolvulaceae | 8 |
| Ipomoea cordatotriloba | Dennst. | Convolvulaceae | 8 |
| Ipomoea corymbosa | (L.) Roth | Convolvulaceae | 8 |
| Ipomoea costellata | Torr. | Convolvulaceae | 8 |
| Ipomoea cristulata | Hallier f. | Convolvulaceae | 8 |
| Ipomoea dumetorum | Willd. | Convolvulaceae | 8 |
| Ipomoea dumosa | (Benth.) L.O.Williams | Convolvulaceae | 8 |
| Ipomoea elongata | Choisy | Convolvulaceae | 8 |
| Ipomoea emetica | Choisy | Convolvulaceae | 8 |
| Ipomoea funis | Cham. & Schltdl. | Convolvulaceae | 8 |
| Ipomoea hartwegii | Benth. | Convolvulaceae | 8 |
| Ipomoea hederacea | Jacq. | Convolvulaceae | 8 |
| Ipomoea hederifolia | L. | Convolvulaceae | 8 |
| Ipomoea imperati | (Vahl) Griseb. | Convolvulaceae | 8 |
| Ipomoea indica | (Burm.) Merr. | Convolvulaceae | 8 |
| Ipomoea intrapilosa | Rose | Convolvulaceae | 8 |
| Ipomoea jalapa | (L.) Pursh | Convolvulaceae | 8 |
| Ipomoea laeta | A.Gray | Convolvulaceae | 8 |
| Ipomoea lindenii | M.Martens & Galeotti | Convolvulaceae | 8 |
| Ipomoea lindheimeri | A.Gray | Convolvulaceae | 8 |
| Ipomoea longifolia | Benth. | Convolvulaceae | 8 |
| Ipomoea mairetii | Choisy | Convolvulaceae | 8 |
| Ipomoea meyeri | (Spreng.) G.Don | Convolvulaceae | 8 |
| Ipomoea microsepala | Benth. | Convolvulaceae | 8 |
| Ipomoea minutiflora | (M.Martens & Galeotti) House | Convolvulaceae | 8 |
| Ipomoea muricata | (L.) Jacq. | Convolvulaceae | 8 |
| Ipomoea murucoides | Roem. & Schult. | Convolvulaceae | 8 |
| Ipomoea nil | (L.) Roth | Convolvulaceae | 8 |
| Ipomoea orizabensis | (G.Pelletan) Ledeb. ex Steud. | Convolvulaceae | 8 |
| Ipomoea parasitica | (Kunth) G.Don | Convolvulaceae | 8 |
| Ipomoea pedicellaris | Benth. | Convolvulaceae | 8 |
| Ipomoea pes-caprae | (L.) R.Br. | Convolvulaceae | 8 |
| Ipomoea plummerae | A.Gray | Convolvulaceae | 8 |
| Ipomoea pubescens | Lam. | Convolvulaceae | 8 |
| Ipomoea purpurea | (L.) Roth | Convolvulaceae | 8 |
| Ipomoea quamoclit | L. | Convolvulaceae | 8 |
| Ipomoea sagittata | Poir. | Convolvulaceae | 8 |
| Ipomoea sescossiana | Baill. | Convolvulaceae | 8 |
| Ipomoea squamosa | Choisy | Convolvulaceae | 8 |
| Ipomoea stans | Cav. | Convolvulaceae | 8 |
| Ipomoea suaveolens | (M.Martens & Galeotti) Hemsl. | Convolvulaceae | 8 |
| Ipomoea ternifolia | Cav. | Convolvulaceae | 8 |
| Ipomoea tiliacea | (Willd.) Choisy | Convolvulaceae | 8 |
| Ipomoea tricolor | Cav. | Convolvulaceae | 8 |
| Ipomoea trifida | (Kunth) G.Don | Convolvulaceae | 8 |
| Ipomoea triloba | L. | Convolvulaceae | 8 |
| Ipomoea wolcottiana | Rose | Convolvulaceae | 8 |
| Ipomopsis aggregata | (Pursh) V.E.Grant | Polemoniaceae | 8 |
| Ipomopsis laxiflora | (J.M.Coult.) V.E.Grant | Polemoniaceae | 8 |
| Ipomopsis longiflora | (Torr.) V.E.Grant | Polemoniaceae | 8 |
| Ipomopsis macombii | (Torr. ex A.Gray) V.E.Grant | Polemoniaceae | 8 |
| Ipomopsis polycladon | (Torr.) V.E.Grant | Polemoniaceae | 8 |
| Ipomopsis thurberi | (A.Gray) V.E.Grant | Polemoniaceae | 8 |
| Iresine ajuscana | Suess. & Beyerle ex Suess. | Amaranthaceae | 8 |
| Iresine calea | (Ibáñez) Standl. | Amaranthaceae | 8 |
| Iresine diffusa | Humb. & Bonpl. ex Willd. | Amaranthaceae | 8 |
| Iresine heterophylla | Standl. | Amaranthaceae | 8 |
| Iresine orientalis | G.L.Nesom | Amaranthaceae | 8 |
| Iresine palmeri | (S.Watson) Standl. | Amaranthaceae | 8 |
| Iresine rhizomatosa | Standl. | Amaranthaceae | 8 |
| Iris missouriensis | Nutt. | Iridaceae | 8 |
| Isocarpha oppositifolia | (L.) Cass. | Asteraceae | 8 |
| Isochilus linearis | (Jacq.) R.Br. | Orchidaceae | 8 |
| Isocoma coronopifolia | Greene | Asteraceae | 8 |
| Isocoma drummondii | Greene | Asteraceae | 8 |
| Isocoma pluriflora | (Torr. & A.Gray) Greene | Asteraceae | 8 |
| Isocoma tenuisecta | Greene | Asteraceae | 8 |
| Isolatocereus dumortieri | (Scheidw.) Backeb. | Cactaceae | 8 |
| Iva annua | L. | Asteraceae | 8 |
| Jacaratia mexicana | A.DC. | Caricaceae | 8 |
| Jacquemontia evolvuloides | Meisn. | Convolvulaceae | 8 |
| Jacquemontia nodiflora | (Desr.) G.Don | Convolvulaceae | 8 |
| Jacquemontia oaxacana | (Meisn.) Hallier f. | Convolvulaceae | 8 |
| Jacquemontia pringlei | A.Gray | Convolvulaceae | 8 |
| Jacquemontia tamnifolia | (L.) Griseb. | Convolvulaceae | 8 |
| Jaegeria hirta | (Lag.) Less. | Asteraceae | 8 |
| Jaltomata procumbens | (Cav.) J.L.Gentry | Solanaceae | 8 |
| Jamesia americana | Torr. & A.Gray | Hydrangeaceae | 8 |
| Jarava ichu | Ruiz & Pav. | Poaceae | 8 |
| Jatropha cathartica | Terán & Berland. | Euphorbiaceae | 8 |
| Jatropha cordata | (Ortega) Müll.Arg. | Euphorbiaceae | 8 |
| Jatropha curcas | L. | Euphorbiaceae | 8 |
| Jatropha dioica | Sessé | Euphorbiaceae | 8 |
| Jatropha gossypiifolia | L. | Euphorbiaceae | 8 |
| Jatropha macrorhiza | Benth. | Euphorbiaceae | 8 |
| Jatropha multifida | L. | Euphorbiaceae | 8 |
| Jefea brevifolia | (A.Gray) Strother | Asteraceae | 8 |
| Johnstonella albida | (Kunth) M.E.Mabry & M.G.Simpson | Boraginaceae | 8 |
| Johnstonella angustifolia | (Torr.) Hasenstab & M.G.Simpson | Boraginaceae | 8 |
| Johnstonella mexicana | (Brandegee) M.E.Mabry & M.G.Simpson | Boraginaceae | 8 |
| Johnstonella pusilla | (Torr. & A.Gray) Hasenstab & M.G.Simpson | Boraginaceae | 8 |
| Juglans major | (Torr.) A.Heller | Juglandaceae | 8 |
| Juglans microcarpa | Berland. | Juglandaceae | 8 |
| Juglans mollis | Engelm. | Juglandaceae | 8 |
| Juncus acuminatus | Michx. | Juncaceae | 8 |
| Juncus anthelatus | (Wiegand) R.E.Brooks & Whittem. | Juncaceae | 8 |
| Juncus articulatus | L. | Juncaceae | 8 |
| Juncus balticus | Willd. | Juncaceae | 8 |
| Juncus biflorus | Elliott | Juncaceae | 8 |
| Juncus bufonius | L. | Juncaceae | 8 |
| Juncus dichotomus | Elliott | Juncaceae | 8 |
| Juncus dudleyi | Wiegand | Juncaceae | 8 |
| Juncus effusus | L. | Juncaceae | 8 |
| Juncus ensifolius | Wikstr. | Juncaceae | 8 |
| Juncus interior | Wiegand | Juncaceae | 8 |
| Juncus marginatus | Rostk. | Juncaceae | 8 |
| Juncus microcephalus | Kunth | Juncaceae | 8 |
| Juncus nodosus | L. | Juncaceae | 8 |
| Juncus tenuis | Willd. | Juncaceae | 8 |
| Juncus torreyi | Coville | Juncaceae | 8 |
| Juncus xiphioides | E.Mey. | Juncaceae | 8 |
| Juniperus ashei | J.Buchholz | Cupressaceae | 8 |
| Juniperus coahuilensis | (Martínez) Gaussen ex R.P.Adams | Cupressaceae | 8 |
| Juniperus deppeana | Steud. | Cupressaceae | 8 |
| Juniperus durangensis | Martínez | Cupressaceae | 8 |
| Juniperus flaccida | Schltdl. | Cupressaceae | 8 |
| Juniperus jaliscana | Martínez | Cupressaceae | 8 |
| Juniperus monosperma | (Engelm.) Sarg. | Cupressaceae | 8 |
| Juniperus pinchotii | Sudw. | Cupressaceae | 8 |
| Juniperus scopulorum | Sarg. | Cupressaceae | 8 |
| Juniperus virginiana | L. | Cupressaceae | 8 |
| Justicia aurea | Schltdl. | Acanthaceae | 8 |
| Justicia brandegeeana | Wassh. & L.B.Sm. | Acanthaceae | 8 |
| Justicia longii | Hilsenb. | Acanthaceae | 8 |
| Justicia macrantha | Benth. | Acanthaceae | 8 |
| Justicia pacifica | (Oerst.) Hemsl. | Acanthaceae | 8 |
| Justicia pilosella | (Nees) Hilsenb. | Acanthaceae | 8 |
| Justicia pringlei | B.L.Rob. | Acanthaceae | 8 |
| Justicia spicigera | Schltdl. | Acanthaceae | 8 |
| Kallstroemia californica | (S.Watson) Vail | Zygophyllaceae | 8 |
| Kallstroemia grandiflora | Torr. ex A.Gray | Zygophyllaceae | 8 |
| Kallstroemia maxima | (L.) Hook. & Arn. | Zygophyllaceae | 8 |
| Kallstroemia parviflora | Norton | Zygophyllaceae | 8 |
| Kallstroemia rosei | Rydb. | Zygophyllaceae | 8 |
| Karwinskia humboldtiana | (Schult.) Zucc. | Rhamnaceae | 8 |
| Kearnemalvastrum lacteum | (Aiton) D.M.Bates | Malvaceae | 8 |
| Kearnemalvastrum subtriflorum | (Lag.) D.M.Bates | Malvaceae | 8 |
| Knowltonia mexicana | (Kunth) Christenh. & Byng | Ranunculaceae | 8 |
| Koeberlinia spinosa | Zucc. | Koeberliniaceae | 8 |
| Koeleria macrantha | (Ledeb.) Schult. | Poaceae | 8 |
| Koeleria spicata | (L.) Barberá, Quintanar, Soreng & P.M.Peterson | Poaceae | 8 |
| Kosteletzkya depressa | (L.) O.J.Blanch., Fryxell & D.M.Bates | Malvaceae | 8 |
| Krameria bicolor | S.Watson | Krameriaceae | 8 |
| Krameria cytisoides | Cav. | Krameriaceae | 8 |
| Krameria erecta | Willd. | Krameriaceae | 8 |
| Krameria ixine | L. | Krameriaceae | 8 |
| Krameria lanceolata | Torr. | Krameriaceae | 8 |
| Krameria pauciflora | DC. | Krameriaceae | 8 |
| Krameria ramosissima | S.Watson | Krameriaceae | 8 |
| Krascheninnikovia ceratoides | (L.) Gueldenst. | Chenopodiaceae | 8 |
| Krigia cespitosa | (Raf.) K.L.Chambers | Asteraceae | 8 |
| Krugiodendron ferreum | (Vahl) Urb. | Rhamnaceae | 8 |
| Lacistema aggregatum | (P.J.Bergius) Rusby | Lacistemataceae | 8 |
| Lactuca graminifolia | Michx. | Asteraceae | 8 |
| Lactuca ludoviciana | (Nutt.) Riddell | Asteraceae | 8 |
| Lactuca oblongifolia | Nutt. | Asteraceae | 8 |
| Laelia albida | Bateman ex Lindl. | Orchidaceae | 8 |
| Laelia anceps | Lindl. | Orchidaceae | 8 |
| Laelia autumnalis | (Lex.) Lindl. | Orchidaceae | 8 |
| Laelia speciosa | (Kunth) Schltr. | Orchidaceae | 8 |
| Laennecia coulteri | (A.Gray) G.L.Nesom | Asteraceae | 8 |
| Laennecia filaginoides | DC. | Asteraceae | 8 |
| Laennecia schiedeana | (Less.) G.L.Nesom | Asteraceae | 8 |
| Laennecia sophiifolia | (Kunth) G.L.Nesom | Asteraceae | 8 |
| Lagascea decipiens | Hemsl. | Asteraceae | 8 |
| Lagascea helianthifolia | Kunth | Asteraceae | 8 |
| Lagascea mollis | Cav. | Asteraceae | 8 |
| Laguncularia racemosa | (L.) C.F.Gaertn. | Combretaceae | 8 |
| Lamourouxia dasyantha | (Cham. & Schltdl.) W.R.Ernst | Orobanchaceae | 8 |
| Lamourouxia macrantha | M.Martens & Galeotti | Orobanchaceae | 8 |
| Lamourouxia multifida | Kunth | Orobanchaceae | 8 |
| Lamourouxia nelsonii | B.L.Rob. & Greenm. | Orobanchaceae | 8 |
| Lamourouxia rhinanthifolia | Kunth | Orobanchaceae | 8 |
| Lamourouxia viscosa | Kunth | Orobanchaceae | 8 |
| Lamourouxia xalapensis | Kunth | Orobanchaceae | 8 |
| Lantana achyranthifolia | Desf. | Verbenaceae | 8 |
| Lantana camara | L. | Verbenaceae | 8 |
| Lantana canescens | Kunth | Verbenaceae | 8 |
| Lantana hirta | Graham | Verbenaceae | 8 |
| Lantana horrida | Kunth | Verbenaceae | 8 |
| Lantana involucrata | L. | Verbenaceae | 8 |
| Lantana trifolia | L. | Verbenaceae | 8 |
| Lantana urticoides | Hayek | Verbenaceae | 8 |
| Lantana velutina | M.Martens & Galeotti | Verbenaceae | 8 |
| Laportea canadensis | (L.) Wedd. | Urticaceae | 8 |
| Lappula occidentalis | (S.Watson) Greene | Boraginaceae | 8 |
| Larrea tridentata | (DC.) Coville | Zygophyllaceae | 8 |
| Lasiacis divaricata | (L.) Hitchc. | Poaceae | 8 |
| Lasiacis ruscifolia | (Kunth) Hitchc. ex Chase | Poaceae | 8 |
| Lasianthaea aurea | (D.Don) K.M.Becker | Asteraceae | 8 |
| Lasianthaea fruticosa | (L.) K.M.Becker | Asteraceae | 8 |
| Lasianthaea podocephala | (A.Gray) K.M.Becker | Asteraceae | 8 |
| Lasianthaea rosei | (Greenm.) McVaugh | Asteraceae | 8 |
| Lathyrus decaphyllus | Pursh | Fabaceae | 8 |
| Lathyrus eucosmus | Butters & H.St.John | Fabaceae | 8 |
| Lathyrus graminifolius | (S.Watson) T.G.White | Fabaceae | 8 |
| Lathyrus lanszwertii | Kellogg | Fabaceae | 8 |
| Lechea mucronata | Raf. | Cistaceae | 8 |
| Leersia hexandra | Sw. | Poaceae | 8 |
| Leersia monandra | Sw. | Poaceae | 8 |
| Leersia oryzoides | (L.) Sw. | Poaceae | 8 |
| Leibnitzia lyrata | (Sch.Bip.) G.L.Nesom | Asteraceae | 8 |
| Lemna aequinoctialis | Welw. | Araceae | 8 |
| Lemna gibba | L. | Araceae | 8 |
| Lemna minor | L. | Araceae | 8 |
| Lemna minuta | Kunth | Araceae | 8 |
| Lemna trisulca | L. | Araceae | 8 |
| Lennoa madreporoides | Lex. | Lennoaceae | 8 |
| Lenophyllum guttatum | Rose | Crassulaceae | 8 |
| Lenophyllum texanum | (Donn.Sm.) Rose | Crassulaceae | 8 |
| Leochilus oncidioides | Knowles & Westc. | Orchidaceae | 8 |
| Lepechinia caulescens | (Ortega) Epling | Lamiaceae | 8 |
| Lepechinia schiedeana | (Schltdl.) Vatke | Lamiaceae | 8 |
| Lepidaploa canescens | (Kunth) H.Rob. | Asteraceae | 8 |
| Lepidium alyssoides | A.Gray | Brassicaceae | 8 |
| Lepidium austrinum | Small | Brassicaceae | 8 |
| Lepidium densiflorum | Schrad. | Brassicaceae | 8 |
| Lepidium fremontii | S.Watson | Brassicaceae | 8 |
| Lepidium lasiocarpum | Nutt. | Brassicaceae | 8 |
| Lepidium montanum | Nutt. | Brassicaceae | 8 |
| Lepidium oblongum | Small | Brassicaceae | 8 |
| Lepidium thurberi | Wooton | Brassicaceae | 8 |
| Lepidium virginicum | L. | Brassicaceae | 8 |
| Leptochloa crinita | (Lag.) P.M.Peterson & N.Snow | Poaceae | 8 |
| Leptochloa nealleyi | Vasey | Poaceae | 8 |
| Leptochloa panicea | (Retz.) Ohwi | Poaceae | 8 |
| Leptochloa panicoides | (J.Presl) Hitchc. | Poaceae | 8 |
| Leptochloa pluriflora | (E.Fourn.) P.M.Peterson & N.Snow | Poaceae | 8 |
| Leptosiphon floribundus | (A.Gray) J.M.Porter & L.A.Johnson | Polemoniaceae | 8 |
| Leptospron adenanthum | (G.Mey.) A.Delgado | Fabaceae | 8 |
| Lepuropetalon spathulatum | Elliott | Celastraceae | 8 |
| Lespedeza repens | (L.) W.P.C.Barton | Fabaceae | 8 |
| Lespedeza texana | Britton | Fabaceae | 8 |
| Lespedeza virginica | (L.) Britton | Fabaceae | 8 |
| Leucaena cuspidata | Standl. | Fabaceae | 8 |
| Leucaena esculenta | (Moc. & Sessé ex DC.) Benth. | Fabaceae | 8 |
| Leucaena leucocephala | (Lam.) de Wit | Fabaceae | 8 |
| Leucaena pulverulenta | (Schltdl.) Benth. | Fabaceae | 8 |
| Leucaena retusa | Benth. | Fabaceae | 8 |
| Leuchtenbergia principis | Hook. | Cactaceae | 8 |
| Leucophyllum ambiguum | Bonpl. | Scrophulariaceae | 8 |
| Leucophyllum candidum | I.M.Johnst. | Scrophulariaceae | 8 |
| Leucophyllum frutescens | (Berland.) I.M.Johnst. | Scrophulariaceae | 8 |
| Leucophyllum minus | A.Gray | Scrophulariaceae | 8 |
| Leymus condensatus | (J.Presl) Á.Löve | Poaceae | 8 |
| Leymus triticoides | (Buckley) Pilg. | Poaceae | 8 |
| Liatris punctata | Hook. | Asteraceae | 8 |
| Libidibia sclerocarpa | (Standl.) Britton & Rose | Fabaceae | 8 |
| Ligusticum porteri | J.M.Coult. & Rose | Apiaceae | 8 |
| Limnodea arkansana | (Nutt.) L.H.Dewey | Poaceae | 8 |
| Limonium carolinianum | (Walter) Britton | Plumbaginaceae | 8 |
| Limonium limbatum | Small | Plumbaginaceae | 8 |
| Limosella aquatica | L. | Plantaginaceae | 8 |
| Lindernia dubia | (L.) Pennell | Linderniaceae | 8 |
| Lindheimera texana | A.Gray & Engelm. | Asteraceae | 8 |
| Lindleya mespiloides | Kunth | Rosaceae | 8 |
| Linum alatum | (Small) H.J.P.Winkl. | Linaceae | 8 |
| Linum aristatum | Engelm. | Linaceae | 8 |
| Linum australe | A.Heller | Linaceae | 8 |
| Linum berlandieri | Hook. | Linaceae | 8 |
| Linum elongatum | H.J.P.Winkl. | Linaceae | 8 |
| Linum lewisii | Pursh | Linaceae | 8 |
| Linum neomexicanum | Greene | Linaceae | 8 |
| Linum pratense | (Norton) Small | Linaceae | 8 |
| Linum puberulum | (Engelm.) A.Heller | Linaceae | 8 |
| Linum rigidum | Pursh | Linaceae | 8 |
| Linum rupestre | Engelm. ex A.Gray | Linaceae | 8 |
| Linum vernale | Wooton | Linaceae | 8 |
| Liparis vexillifera | (Lex.) Cogn. | Orchidaceae | 8 |
| Lippia alba | (Mill.) N.E.Br. ex Britton & P.Wilson | Verbenaceae | 8 |
| Lippia chiapasensis | Loes. | Verbenaceae | 8 |
| Lippia dulcis | Trevir. | Verbenaceae | 8 |
| Lippia myriocephala | Schltdl. & Cham. | Verbenaceae | 8 |
| Lippia stoechadifolia | (L.) Kunth | Verbenaceae | 8 |
| Lippia umbellata | Cav. | Verbenaceae | 8 |
| Liquidambar styraciflua | L. | Altingiaceae | 8 |
| Lithospermum cobrense | Greene | Boraginaceae | 8 |
| Lithospermum distichum | Ortega | Boraginaceae | 8 |
| Lithospermum exsertum | (D.Don) J.I.Cohen | Boraginaceae | 8 |
| Lithospermum incisum | Lehm. | Boraginaceae | 8 |
| Lithospermum matamorense | DC. | Boraginaceae | 8 |
| Lithospermum mirabile | Small | Boraginaceae | 8 |
| Lithospermum multiflorum | Torr. ex A.Gray | Boraginaceae | 8 |
| Lithospermum occidentale | (Mack.) Weakley, Witsell & D.Estes | Boraginaceae | 8 |
| Lithospermum viride | Greene | Boraginaceae | 8 |
| Litsea glaucescens | Kunth | Lauraceae | 8 |
| Llavea cordifolia | Lag. | Pteridaceae | 8 |
| Lobelia anatina | E.Wimm. | Campanulaceae | 8 |
| Lobelia berlandieri | A.DC. | Campanulaceae | 8 |
| Lobelia cardinalis | L. | Campanulaceae | 8 |
| Lobelia fenestralis | Cav. | Campanulaceae | 8 |
| Lobelia irasuensis | Planch. & Oerst. | Campanulaceae | 8 |
| Lobelia laxiflora | Kunth | Campanulaceae | 8 |
| Lobelia nana | Kunth | Campanulaceae | 8 |
| Lobelia sublibera | S.Watson | Campanulaceae | 8 |
| Loeselia amplectens | (Hook. & Arn.) Benth. ex DC. | Polemoniaceae | 8 |
| Loeselia ciliata | L. | Polemoniaceae | 8 |
| Loeselia coerulea | G.Don | Polemoniaceae | 8 |
| Loeselia glandulosa | (Cav.) G.Don | Polemoniaceae | 8 |
| Loeselia greggii | S.Watson | Polemoniaceae | 8 |
| Loeselia mexicana | Brand | Polemoniaceae | 8 |
| Loeselia pumila | Walp. | Polemoniaceae | 8 |
| Lonchocarpus rugosus | Benth. | Fabaceae | 8 |
| Lonicera albiflora | Torr. & A.Gray | Caprifoliaceae | 8 |
| Lonicera involucrata | (Richardson) Banks ex Spreng. | Caprifoliaceae | 8 |
| Lonicera pilosa | Willd. ex Kunth | Caprifoliaceae | 8 |
| Lopezia miniata | DC. | Onagraceae | 8 |
| Lopezia racemosa | Cav. | Onagraceae | 8 |
| Lophocereus marginatus | (DC.) S.Arias & Terrazas | Cactaceae | 8 |
| Lophophora diffusa | (Croizat) Bravo | Cactaceae | 8 |
| Lophophora williamsii | (Lem. ex Salm-Dyck) J.M.Coult. | Cactaceae | 8 |
| Lophosoria quadripinnata | (J.F.Gmel.) C.Chr. | Dicksoniaceae | 8 |
| Lophospermum erubescens | D.Don | Plantaginaceae | 8 |
| Lorandersonia baileyi | (Wooton & Standl.) Urbatsch, R.P.Roberts & Neubig | Asteraceae | 8 |
| Lorandersonia pulchella | (A.Gray) Urbatsch, R.P.Roberts & Neubig | Asteraceae | 8 |
| Ludwigia adscendens | (L.) H.Hara | Onagraceae | 8 |
| Ludwigia bonariensis | (Micheli) H.Hara | Onagraceae | 8 |
| Ludwigia leptocarpa | (Nutt.) H.Hara | Onagraceae | 8 |
| Ludwigia octovalvis | (Jacq.) P.H.Raven | Onagraceae | 8 |
| Ludwigia palustris | (L.) Elliott | Onagraceae | 8 |
| Ludwigia peploides | (Kunth) P.H.Raven | Onagraceae | 8 |
| Ludwigia repens | J.R.Forst. | Onagraceae | 8 |
| Luehea candida | (Moc. & Sessé ex DC.) Mart. | Malvaceae | 8 |
| Lupinus argenteus | Pursh | Fabaceae | 8 |
| Lupinus aschenbornii | S.Schauer | Fabaceae | 8 |
| Lupinus brevicaulis | S.Watson | Fabaceae | 8 |
| Lupinus elegans | Kunth | Fabaceae | 8 |
| Lupinus havardii | S.Watson | Fabaceae | 8 |
| Lupinus huachucanus | M.E.Jones | Fabaceae | 8 |
| Lupinus latifolius | Lindl. ex J.Agardh | Fabaceae | 8 |
| Lupinus montanus | Kunth | Fabaceae | 8 |
| Lupinus subcarnosus | Hook. | Fabaceae | 8 |
| Lupinus texensis | Hook. | Fabaceae | 8 |
| Luziola fluitans | (Michx.) Terrell & H.Rob. | Poaceae | 8 |
| Luzula comosa | E.Mey. | Juncaceae | 8 |
| Lycianthes ciliolata | (M.Martens & Galeotti) Bitter | Solanaceae | 8 |
| Lycianthes scandens | (Mill.) M.Nee | Solanaceae | 8 |
| Lycium andersonii | A.Gray | Solanaceae | 8 |
| Lycium berlandieri | Dunal | Solanaceae | 8 |
| Lycium californicum | Nutt. ex A.Gray | Solanaceae | 8 |
| Lycium carolinianum | Walter | Solanaceae | 8 |
| Lycium pallidum | Miers | Solanaceae | 8 |
| Lycium parishii | A.Gray | Solanaceae | 8 |
| Lycium torreyi | A.Gray | Solanaceae | 8 |
| Lygodesmia texana | (Torr. & A.Gray) Greene ex Small | Asteraceae | 8 |
| Lygodium heterodoxum | Kunze | Lygodiaceae | 8 |
| Lygodium venustum | Sw. | Lygodiaceae | 8 |
| Lysiloma acapulcense | (Kunth) Benth. | Fabaceae | 8 |
| Lysiloma divaricatum | (Jacq.) J.F.Macbr. | Fabaceae | 8 |
| Lysimachia minima | (L.) U.Manns & Anderb. | Primulaceae | 8 |
| Lysimachia ovalis | (Ruiz & Pav.) U.Manns & Anderb. | Primulaceae | 8 |
| Lythrum alatum | Pursh | Lythraceae | 8 |
| Lythrum californicum | Torr. & A.Gray | Lythraceae | 8 |
| Lythrum ovalifolium | (A.Gray) Shuttlew. ex Koehne | Lythraceae | 8 |
| Machaeranthera tagetina | Greene | Asteraceae | 8 |
| Machaeranthera tanacetifolia | (Kunth) Nees | Asteraceae | 8 |
| Machaerium riparium | Brandegee | Fabaceae | 8 |
| Machaonia coulteri | (Hook.f.) Standl. | Rubiaceae | 8 |
| Maclura tinctoria | (L.) D.Don ex G.Don | Moraceae | 8 |
| Macroptilium atropurpureum | (DC.) Urb. | Fabaceae | 8 |
| Macroptilium gibbosifolium | (Ortega) A.Delgado | Fabaceae | 8 |
| Macroptilium lathyroides | (L.) Urb. | Fabaceae | 8 |
| Macroscepis diademata | (Ker Gawl.) W.D.Stevens | Apocynaceae | 8 |
| Magnolia dealbata | Zucc. | Magnoliaceae | 8 |
| Magnolia pugana | (Iltis & A.Vázquez) A.Vázquez & Carvajal | Magnoliaceae | 8 |
| Maianthemum racemosum | (L.) Link | Asparagaceae | 8 |
| Maianthemum stellatum | (L.) Link | Asparagaceae | 8 |
| Malachra alceifolia | Jacq. | Malvaceae | 8 |
| Malachra capitata | (L.) L. | Malvaceae | 8 |
| Malachra fasciata | Jacq. | Malvaceae | 8 |
| Malacomeles denticulata | (Kunth) Decne. | Rosaceae | 8 |
| Malacomeles nervosa | (Decne.) G.N.Jones | Rosaceae | 8 |
| Malacomeles pringlei | (Koehne) B.L.Turner | Rosaceae | 8 |
| Malacothrix fendleri | A.Gray | Asteraceae | 8 |
| Malaxis brachyrrhynchos | (Rchb.f.) Ames | Orchidaceae | 8 |
| Malaxis macrostachya | (Lex.) Kuntze | Orchidaceae | 8 |
| Malaxis unifolia | Michx. | Orchidaceae | 8 |
| Malosma laurina | (Nutt.) Nutt. ex Abrams | Anacardiaceae | 8 |
| Malpighia emarginata | DC. | Malpighiaceae | 8 |
| Malpighia glabra | L. | Malpighiaceae | 8 |
| Malvastrum americanum | (L.) Torr. | Malvaceae | 8 |
| Malvastrum coromandelianum | (L.) Garcke | Malvaceae | 8 |
| Malvaviscus arboreus | Dill. ex Cav. | Malvaceae | 8 |
| Malvaviscus penduliflorus | DC. | Malvaceae | 8 |
| Malvella lepidota | (A.Gray) Fryxell | Malvaceae | 8 |
| Malvella leprosa | (Ortega) Krapov. | Malvaceae | 8 |
| Malvella sagittifolia | (A.Gray) Fryxell | Malvaceae | 8 |
| Mammillaria albiflora | (Werderm.) Backeb. | Cactaceae | 8 |
| Mammillaria beneckei | Ehrenb. | Cactaceae | 8 |
| Mammillaria candida | Scheidw. | Cactaceae | 8 |
| Mammillaria compressa | DC. | Cactaceae | 8 |
| Mammillaria crinita | DC. | Cactaceae | 8 |
| Mammillaria densispina | (J.M.Coult.) Orcutt | Cactaceae | 8 |
| Mammillaria erythrosperma | Boed. | Cactaceae | 8 |
| Mammillaria formosa | Galeotti ex Scheidw. | Cactaceae | 8 |
| Mammillaria geminispina | Haw. | Cactaceae | 8 |
| Mammillaria gigantea | Hildm. ex K.Schum. | Cactaceae | 8 |
| Mammillaria grusonii | Runge | Cactaceae | 8 |
| Mammillaria haageana | Pfeiff. | Cactaceae | 8 |
| Mammillaria heyderi | Muehlenpf. | Cactaceae | 8 |
| Mammillaria lasiacantha | Engelm. | Cactaceae | 8 |
| Mammillaria lenta | K.Brandegee | Cactaceae | 8 |
| Mammillaria longimamma | DC. | Cactaceae | 8 |
| Mammillaria magnimamma | Haw. | Cactaceae | 8 |
| Mammillaria muehlenpfordtii | C.F.Först. | Cactaceae | 8 |
| Mammillaria nana | Backeb. | Cactaceae | 8 |
| Mammillaria orcuttii | Boed. | Cactaceae | 8 |
| Mammillaria parkinsonii | Ehrenb. | Cactaceae | 8 |
| Mammillaria perbella | Hildm. ex K.Schum. | Cactaceae | 8 |
| Mammillaria petterssonii | Hildm. | Cactaceae | 8 |
| Mammillaria pottsii | Scheer ex Salm-Dyck | Cactaceae | 8 |
| Mammillaria scrippsiana | (Britton & Rose) Orcutt | Cactaceae | 8 |
| Mammillaria senilis | Lodd. ex Salm-Dyck | Cactaceae | 8 |
| Mammillaria sphaerica | A.Dietr. | Cactaceae | 8 |
| Mammillaria uncinata | Zucc. ex Pfeiff. | Cactaceae | 8 |
| Mammillaria wagneriana | Boed. | Cactaceae | 8 |
| Mammillaria zephyranthoides | Scheidw. | Cactaceae | 8 |
| Mandevilla foliosa | (Müll.Arg.) Hemsl. | Apocynaceae | 8 |
| Mandevilla hypoleuca | (Benth.) Pichon | Apocynaceae | 8 |
| Mandevilla lanuginosa | (M.Martens & Galeotti) Pichon | Apocynaceae | 8 |
| Mandevilla macrosiphon | (Torr.) Pichon | Apocynaceae | 8 |
| Mandevilla subsagittata | (Ruiz & Pav.) Woodson | Apocynaceae | 8 |
| Mandevilla torosa | (Jacq.) Woodson | Apocynaceae | 8 |
| Manihot angustiloba | (Torr.) Müll.Arg. | Euphorbiaceae | 8 |
| Manihot subspicata | D.J.Rogers & Appan | Euphorbiaceae | 8 |
| Manihot walkerae | Croizat | Euphorbiaceae | 8 |
| Manilkara zapota | (L.) P.Royen | Sapotaceae | 8 |
| Maranta arundinacea | L. | Marantaceae | 8 |
| Margaritaria nobilis | L.f. | Phyllanthaceae | 8 |
| Marina calycosa | (A.Gray) Barneby | Fabaceae | 8 |
| Marina filiciformis | (B.L.Rob. & Greenm.) Piñeros-U. & F.González | Fabaceae | 8 |
| Marina parryi | (Torr. & A.Gray) Barneby | Fabaceae | 8 |
| Marina spiciformis | (Rose) Barneby | Fabaceae | 8 |
| Mariosousa coulteri | (Benth.) Seigler & Ebinger | Fabaceae | 8 |
| Marsilea macropoda | Engelm. ex A.Braun | Marsileaceae | 8 |
| Marsilea vestita | Hook. & Grev. | Marsileaceae | 8 |
| Martynia annua | L. | Martyniaceae | 8 |
| Matayba oppositifolia | (A.Rich.) Britton | Sapindaceae | 8 |
| Maurandella antirrhiniflora | (Humb. & Bonpl. ex Willd.) Rothm. | Plantaginaceae | 8 |
| Maurandya barclayana | Lindl. | Plantaginaceae | 8 |
| Maxillaria densa | Lindl. | Orchidaceae | 8 |
| Maxillaria variabilis | Bateman ex Lindl. | Orchidaceae | 8 |
| Mayaca fluviatilis | Aubl. | Mayacaceae | 8 |
| Maytenus phyllanthoides | Benth. | Celastraceae | 8 |
| Mecardonia procumbens | (Mill.) Small | Plantaginaceae | 8 |
| Mecardonia vandellioides | (Kunth) Pennell | Plantaginaceae | 8 |
| Medranoa palmeri | (A.Gray) G.L.Nesom | Asteraceae | 8 |
| Megacorax gracielanus | S.González & W.L.Wagner | Onagraceae | 8 |
| Melampodium cinereum | DC. | Asteraceae | 8 |
| Melampodium divaricatum | DC. | Asteraceae | 8 |
| Melampodium gracile | Less. | Asteraceae | 8 |
| Melampodium leucanthum | Torr. & A.Gray | Asteraceae | 8 |
| Melampodium montanum | Benth. | Asteraceae | 8 |
| Melampodium perfoliatum | (Cav.) Kunth | Asteraceae | 8 |
| Melampodium sericeum | Lag. | Asteraceae | 8 |
| Melampodium strigosum | Stuessy | Asteraceae | 8 |
| Melanthera nivea | (L.) Small | Asteraceae | 8 |
| Melica nitens | (Scribn.) Nutt. ex Piper | Poaceae | 8 |
| Meliosma dentata | (Liebm.) Urb. | Sabiaceae | 8 |
| Melochia nodiflora | Sw. | Malvaceae | 8 |
| Melochia pyramidata | L. | Malvaceae | 8 |
| Melochia tomentosa | L. | Malvaceae | 8 |
| Melothria pendula | L. | Cucurbitaceae | 8 |
| Melothria scabra | Naudin | Cucurbitaceae | 8 |
| Menispermum canadense | L. | Menispermaceae | 8 |
| Menodora heterophylla | Moric. ex DC. | Oleaceae | 8 |
| Menodora longiflora | Engelm. ex A.Gray | Oleaceae | 8 |
| Menodora scabra | Engelm. ex A.Gray | Oleaceae | 8 |
| Mentha canadensis | L. | Lamiaceae | 8 |
| Mentzelia albicaulis | (Douglas ex Hook.) Douglas ex Torr. & A.Gray | Loasaceae | 8 |
| Mentzelia aspera | L. | Loasaceae | 8 |
| Mentzelia hispida | Willd. | Loasaceae | 8 |
| Mentzelia longiloba | J.Darl. | Loasaceae | 8 |
| Mentzelia procera | (Wooton & Standl.) J.J.Schenk & L.Hufford | Loasaceae | 8 |
| Mentzelia texana | Urb. & Gilg | Loasaceae | 8 |
| Mesadenus lucayanus | (Britton) Schltr. | Orchidaceae | 8 |
| Mesechites trifidus | (Jacq.) Müll.Arg. | Apocynaceae | 8 |
| Mesosphaerum oblongifolium | (Benth.) Kuntze | Lamiaceae | 8 |
| Mesosphaerum pectinatum | (L.) Kuntze | Lamiaceae | 8 |
| Mesosphaerum urticodes | (Kunth) Kuntze | Lamiaceae | 8 |
| Mespilodaphne veraguensis | (Meisn.) Rohwer | Lauraceae | 8 |
| Metastelma arizonicum | A.Gray | Apocynaceae | 8 |
| Metastelma barbigerum | Scheele | Apocynaceae | 8 |
| Metastelma lanceolatum | Schltr. | Apocynaceae | 8 |
| Metastelma palmeri | S.Watson | Apocynaceae | 8 |
| Metastelma schlechtendalii | Decne. | Apocynaceae | 8 |
| Meximalva filipes | (A.Gray) Fryxell | Malvaceae | 8 |
| Miconia cornoides | (Schltdl. & Cham.) Almeda | Melastomataceae | 8 |
| Miconia glaberrima | (Schltdl.) Naudin | Melastomataceae | 8 |
| Miconia laevigata | (L.) DC. | Melastomataceae | 8 |
| Miconia mexicana | (Bonpl.) Naudin | Melastomataceae | 8 |
| Miconia petiolaris | (Schltdl.) Michelang. | Melastomataceae | 8 |
| Miconia xalapensis | (Bonpl.) M.Gómez | Melastomataceae | 8 |
| Micranthemum umbrosum | (J.F.Gmel.) S.F.Blake | Linderniaceae | 8 |
| Micranthes eriophora | (S.Watson) Small | Saxifragaceae | 8 |
| Microchilus querceticola | (Lindl.) D.Dietr. | Orchidaceae | 8 |
| Microgramma nitida | (J.Sm.) A.R.Sm. | Polypodiaceae | 8 |
| Mikania cordifolia | (L.f.) Willd. | Asteraceae | 8 |
| Mikania micrantha | Kunth | Asteraceae | 8 |
| Mikania scandens | (L.) Willd. | Asteraceae | 8 |
| Milla biflora | Cav. | Asparagaceae | 8 |
| Milleria quinqueflora | L. | Asteraceae | 8 |
| Mimophytum alienoides | (G.L.Nesom) G.L.Nesom | Boraginaceae | 8 |
| Mimophytum cardiophyllum | (A.Gray ex Hemsl.) R.R.Mill ex Holstein & Weigend | Boraginaceae | 8 |
| Mimosa aculeaticarpa | Ortega | Fabaceae | 8 |
| Mimosa albida | Humb. & Bonpl. ex Willd. | Fabaceae | 8 |
| Mimosa berlandieri | A.Gray | Fabaceae | 8 |
| Mimosa biuncifera | Benth. | Fabaceae | 8 |
| Mimosa borealis | A.Gray | Fabaceae | 8 |
| Mimosa diplotricha | C.Wright | Fabaceae | 8 |
| Mimosa distachya | Cav. | Fabaceae | 8 |
| Mimosa dysocarpa | Benth. | Fabaceae | 8 |
| Mimosa grahamii | A.Gray | Fabaceae | 8 |
| Mimosa malacophylla | A.Gray | Fabaceae | 8 |
| Mimosa quadrivalvis | L. | Fabaceae | 8 |
| Mimosa strigillosa | Torr. & A.Gray | Fabaceae | 8 |
| Mimosa tenuiflora | (Willd.) Poir. | Fabaceae | 8 |
| Mimosa texana | (A.Gray) Small | Fabaceae | 8 |
| Mimosa tricephala | Schltdl. & Cham. | Fabaceae | 8 |
| Mimosa zygophylla | Benth. | Fabaceae | 8 |
| Mirabilis albida | (Walter) Heimerl | Nyctaginaceae | 8 |
| Mirabilis coccinea | (Torr.) Benth. & Hook.f. | Nyctaginaceae | 8 |
| Mirabilis glabra | (S.Watson) Standl. | Nyctaginaceae | 8 |
| Mirabilis jalapa | L. | Nyctaginaceae | 8 |
| Mirabilis linearis | (Pursh) Heimerl | Nyctaginaceae | 8 |
| Mirabilis longiflora | L. | Nyctaginaceae | 8 |
| Mirabilis melanotricha | (Standl.) Spellenb. | Nyctaginaceae | 8 |
| Mirabilis multiflora | (Torr.) A.Gray | Nyctaginaceae | 8 |
| Mirabilis oxybaphoides | (A.Gray) A.Gray | Nyctaginaceae | 8 |
| Mirabilis violacea | Heimerl | Nyctaginaceae | 8 |
| Mirabilis viscosa | Cav. | Nyctaginaceae | 8 |
| Mitchella repens | L. | Rubiaceae | 8 |
| Mitracarpus hirtus | (L.) DC. | Rubiaceae | 8 |
| Mitreola petiolata | (J.F.Gmel.) Torr. & A.Gray | Loganiaceae | 8 |
| Mollugo verticillata | L. | Molluginaceae | 8 |
| Monarda citriodora | Cerv. ex Lag. | Lamiaceae | 8 |
| Monarda fistulosa | L. | Lamiaceae | 8 |
| Monarda pringlei | Fernald | Lamiaceae | 8 |
| Monarda punctata | L. | Lamiaceae | 8 |
| Monnina ciliolata | Moc. & Sessé ex DC. | Polygalaceae | 8 |
| Monnina wrightii | A.Gray | Polygalaceae | 8 |
| Monnina xalapensis | Kunth | Polygalaceae | 8 |
| Monochaetum floribundum | Naudin | Melastomataceae | 8 |
| Monotropa uniflora | L. | Ericaceae | 8 |
| Monstera acuminata | K.Koch | Araceae | 8 |
| Monstera siltepecana | Matuda | Araceae | 8 |
| Montanoa bipinnatifida | (Kunth) K.Koch | Asteraceae | 8 |
| Montanoa frutescens | Mairet ex DC. | Asteraceae | 8 |
| Montanoa leucantha | (Lag.) S.F.Blake | Asteraceae | 8 |
| Montanoa tomentosa | Cerv. | Asteraceae | 8 |
| Montia chamissoi | (Ledeb. ex Spreng.) Greene | Montiaceae | 8 |
| Morisonia americana | L. | Capparaceae | 8 |
| Morisonia flexuosa | L. | Capparaceae | 8 |
| Morisonia incana | (Kunth) Christenh. & Byng | Capparaceae | 8 |
| Morisonia indica | (L.) ined. | Capparaceae | 8 |
| Morkillia acuminata | Rose & J.H.Painter | Zygophyllaceae | 8 |
| Mortonia greggii | A.Gray | Celastraceae | 8 |
| Mortonia scabrella | A.Gray | Celastraceae | 8 |
| Morus celtidifolia | Kunth | Moraceae | 8 |
| Morus microphylla | Buckley | Moraceae | 8 |
| Mouriri myrtilloides | Poir. | Melastomataceae | 8 |
| Moussonia deppeana | (Schltdl. & Cham.) Hanst. | Gesneriaceae | 8 |
| Mucuna argyrophylla | Standl. | Fabaceae | 8 |
| Muenchhusia moscheutos | (L.) M.M.Hanes & R.L.Barrett | Malvaceae | 8 |
| Muhlenbergia alopecuroides | (Griseb.) P.M.Peterson & Columbus | Poaceae | 8 |
| Muhlenbergia arenacea | (Buckley) Hitchc. | Poaceae | 8 |
| Muhlenbergia arenicola | Buckley | Poaceae | 8 |
| Muhlenbergia asperifolia | (Nees & Meyen ex Trin.) Parodi | Poaceae | 8 |
| Muhlenbergia capillaris | (Lam.) Trin. | Poaceae | 8 |
| Muhlenbergia cuspidata | (Torr. ex Hook.) Rydb. | Poaceae | 8 |
| Muhlenbergia depauperata | Scribn. | Poaceae | 8 |
| Muhlenbergia emersleyi | Vasey | Poaceae | 8 |
| Muhlenbergia implicata | (Kunth) Trin. | Poaceae | 8 |
| Muhlenbergia lindheimeri | Hitchc. | Poaceae | 8 |
| Muhlenbergia longiligula | Hitchc. | Poaceae | 8 |
| Muhlenbergia mexicana | (L.) Trin. | Poaceae | 8 |
| Muhlenbergia microsperma | Trin. | Poaceae | 8 |
| Muhlenbergia minutissima | (Steud.) Swallen | Poaceae | 8 |
| Muhlenbergia montana | (Nutt.) Hitchc. | Poaceae | 8 |
| Muhlenbergia paniculata | (Nutt.) P.M.Peterson | Poaceae | 8 |
| Muhlenbergia peruviana | (P.Beauv.) Steud. | Poaceae | 8 |
| Muhlenbergia phalaroides | (Kunth) P.M.Peterson | Poaceae | 8 |
| Muhlenbergia porteri | Scribn. | Poaceae | 8 |
| Muhlenbergia racemosa | (Michx.) Britton, Sterns & Poggenb. | Poaceae | 8 |
| Muhlenbergia reverchonii | Vasey & Scribn. | Poaceae | 8 |
| Muhlenbergia richardsonis | (Trin.) Rydb. | Poaceae | 8 |
| Muhlenbergia rigens | (Benth.) Hitchc. | Poaceae | 8 |
| Muhlenbergia rigida | (Kunth) Kunth | Poaceae | 8 |
| Muhlenbergia robusta | (E.Fourn.) Hitchc. | Poaceae | 8 |
| Muhlenbergia schreberi | J.F.Gmel. | Poaceae | 8 |
| Muhlenbergia setifolia | Vasey | Poaceae | 8 |
| Muhlenbergia sinuosa | Swallen | Poaceae | 8 |
| Muhlenbergia spiciformis | Trin. | Poaceae | 8 |
| Muhlenbergia torreyi | (Kunth) Hitchc. ex Bush | Poaceae | 8 |
| Muhlenbergia tricholepis | (Torr.) P.M.Peterson | Poaceae | 8 |
| Muhlenbergia utilis | (Torr.) Hitchc. | Poaceae | 8 |
| Muhlenbergia wrightii | Vasey ex J.M.Coult. | Poaceae | 8 |
| Munroa pulchella | (Kunth) Amarilla | Poaceae | 8 |
| Munroa squarrosa | (Nutt.) Torr. | Poaceae | 8 |
| Muntingia calabura | L. | Muntingiaceae | 8 |
| Myrcianthes fragrans | (Sw.) McVaugh | Myrtaceae | 8 |
| Myrica cerifera | L. | Myricaceae | 8 |
| Myriophyllum heterophyllum | Michx. | Haloragaceae | 8 |
| Myriophyllum hippuroides | Nutt. ex Torr. & A.Gray | Haloragaceae | 8 |
| Myriophyllum pinnatum | (Walter) Britton, Sterns & Poggenb. | Haloragaceae | 8 |
| Myriopteris alabamensis | (Buckley) Grusz & Windham | Pteridaceae | 8 |
| Myriopteris aurea | (Poir.) Grusz & Windham | Pteridaceae | 8 |
| Myriopteris covillei | (Maxon) Á.Löve & D.Löve | Pteridaceae | 8 |
| Myriopteris fendleri | Fourn. | Pteridaceae | 8 |
| Myriopteris lendigera | (Cav.) J.Sm. | Pteridaceae | 8 |
| Myriopteris lindheimeri | J.Sm. | Pteridaceae | 8 |
| Myriopteris microphylla | (Sw.) Grusz & Windham | Pteridaceae | 8 |
| Myriopteris myriophylla | J.Sm. | Pteridaceae | 8 |
| Myriopteris rufa | Fée | Pteridaceae | 8 |
| Myriopteris tomentosa | (Link) Fée | Pteridaceae | 8 |
| Myriopteris windhamii | Grusz | Pteridaceae | 8 |
| Myriopteris wootonii | (Maxon) Grusz & Windham | Pteridaceae | 8 |
| Myriopteris wrightii | (Hook.) Grusz & Windham | Pteridaceae | 8 |
| Myriopus volubilis | (L.) Small | Heliotropiaceae | 8 |
| Myrmecophila grandiflora | (Lindl.) Carnevali & J.L.Tapia & I.Ramírez | Orchidaceae | 8 |
| Myrsine coriacea | (Sw.) R.Br. ex Roem. & Schult. | Primulaceae | 8 |
| Myrtillocactus geometrizans | (Mart. ex Pfeiff.) Console | Cactaceae | 8 |
| Najas guadalupensis | (Spreng.) Magnus | Hydrocharitaceae | 8 |
| Najas marina | L. | Hydrocharitaceae | 8 |
| Najas wrightiana | A.Braun | Hydrocharitaceae | 8 |
| Nama carnosa | (Wooton) C.L.Hitchc. | Namaceae | 8 |
| Nama demissa | A.Gray | Namaceae | 8 |
| Nama dichotoma | (Ruiz & Pav.) Choisy | Namaceae | 8 |
| Nama havardii | A.Gray | Namaceae | 8 |
| Nama hispida | A.Gray | Namaceae | 8 |
| Nama jamaicensis | L. | Namaceae | 8 |
| Nama sericea | Willd. ex Schult. | Namaceae | 8 |
| Nama stenocarpa | A.Gray | Namaceae | 8 |
| Nama stevensii | C.L.Hitchc. | Namaceae | 8 |
| Nama xylopoda | (Wooton & Standl.) C.L.Hitchc. | Namaceae | 8 |
| Nanogalactia brachystachys | (Benth.) L.P.Queiroz | Fabaceae | 8 |
| Nanogalactia heterophylla | (Gillies ex Hook.) L.P.Queiroz | Fabaceae | 8 |
| Nassella leucotricha | (Trin. & Rupr.) R.W.Pohl | Poaceae | 8 |
| Nassella tenuissima | (Trin.) Barkworth | Poaceae | 8 |
| Nassella viridula | (Trin.) Barkworth | Poaceae | 8 |
| Neea psychotrioides | Donn.Sm. | Nyctaginaceae | 8 |
| Neltuma glandulosa | (Torr.) Britton & Rose | Fabaceae | 8 |
| Neltuma juliflora | (Sw.) Raf. | Fabaceae | 8 |
| Neltuma laevigata | (Humb. & Bonpl. ex Willd.) Britton & Rose | Fabaceae | 8 |
| Neltuma odorata | (Torr. & Frém.) C.E.Hughes & G.P.Lewis | Fabaceae | 8 |
| Neltuma velutina | (Wooton) Britton & Rose | Fabaceae | 8 |
| Nelumbo lutea | (Willd.) Pers. | Nelumbonaceae | 8 |
| Nemastylis tenuis | (Herb.) Benth. & Hook.f. ex S.Watson | Iridaceae | 8 |
| Nephroia carolina | (L.) L.Lian & Wei Wang | Menispermaceae | 8 |
| Nephroia diversifolia | (DC.) L.Lian & Wei Wang | Menispermaceae | 8 |
| Nephrolepis biserrata | (Sw.) Schott | Nephrolepidaceae | 8 |
| Neptunia plena | (L.) Benth. | Fabaceae | 8 |
| Neptunia pubescens | Benth. | Fabaceae | 8 |
| Nerisyrenia camporum | (A.Gray) Greene | Brassicaceae | 8 |
| Nerisyrenia linearifolia | Greene | Brassicaceae | 8 |
| Nertera granadensis | (Mutis ex L.f.) Druce | Rubiaceae | 8 |
| Nicotiana obtusifolia | M.Martens & Galeotti | Solanaceae | 8 |
| Nicotiana plumbaginifolia | Viv. | Solanaceae | 8 |
| Nidema boothii | (Lindl.) Schltr. | Orchidaceae | 8 |
| Niphidium crassifolium | (L.) Lellinger | Polypodiaceae | 8 |
| Nissolia fruticosa | Jacq. | Fabaceae | 8 |
| Nissolia microptera | Poir. | Fabaceae | 8 |
| Nissolia platycalyx | S.Watson | Fabaceae | 8 |
| Nissolia pringlei | Rose | Fabaceae | 8 |
| Nissolia schottii | A.Gray | Fabaceae | 8 |
| Noccaea fendleri | (A.Gray) Holub | Brassicaceae | 8 |
| Nolina cespitifera | Trel. | Asparagaceae | 8 |
| Nolina erumpens | (Torr.) S.Watson | Asparagaceae | 8 |
| Nolina micrantha | I.M.Johnst. | Asparagaceae | 8 |
| Nolina microcarpa | S.Watson | Asparagaceae | 8 |
| Nolina parviflora | (Kunth) Hemsl. | Asparagaceae | 8 |
| Nolina texana | S.Watson | Asparagaceae | 8 |
| Notholaena aschenborniana | Klotzsch | Pteridaceae | 8 |
| Notholaena brachypus | (Kunze) J.Sm. | Pteridaceae | 8 |
| Notholaena candida | (M.Martens & Galeotti) Hook. | Pteridaceae | 8 |
| Notholaena lemmonii | D.C.Eaton | Pteridaceae | 8 |
| Nothoscordum bivalve | (L.) Britton | Amaryllidaceae | 8 |
| Nuphar advena | (Aiton) W.T.Aiton | Nymphaeaceae | 8 |
| Nuttallanthus canadensis | (L.) D.A.Sutton | Plantaginaceae | 8 |
| Nyctaginia capitata | Choisy | Nyctaginaceae | 8 |
| Nyctocereus serpentinus | (Lag. & Rodr.) Britton & Rose | Cactaceae | 8 |
| Nymphaea ampla | (Salisb.) DC. | Nymphaeaceae | 8 |
| Nymphaea elegans | Hook. | Nymphaeaceae | 8 |
| Nymphaea gracilis | Zucc. | Nymphaeaceae | 8 |
| Nymphaea mexicana | Zucc. | Nymphaeaceae | 8 |
| Nymphaea odorata | Aiton | Nymphaeaceae | 8 |
| Nymphoides fallax | Ornduff | Menyanthaceae | 8 |
| Nymphoides humboldtiana | (Kunth) Kuntze | Menyanthaceae | 8 |
| Nyssa sylvatica | Marshall | Nyssaceae | 8 |
| Obregonia denegrii | Frič | Cactaceae | 8 |
| Ocimum campechianum | Mill. | Lamiaceae | 8 |
| Ocimum carnosum | (Spreng.) Link & Otto ex Benth. | Lamiaceae | 8 |
| Ocotea puberula | (Rich.) Nees | Lauraceae | 8 |
| Odontonema callistachyum | (Schltdl. & Cham.) Kuntze | Acanthaceae | 8 |
| Odontostephana reticulata | (Engelm. ex A.Gray) Morillo, Liede & Meve | Apocynaceae | 8 |
| Oenothera albicaulis | Nutt. ex Pursh | Onagraceae | 8 |
| Oenothera biennis | L. | Onagraceae | 8 |
| Oenothera boquillensis | (P.H.Raven & D.P.Greg.) W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera brachycarpa | A.Gray | Onagraceae | 8 |
| Oenothera calcicola | (P.H.Raven & D.P.Greg.) W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera capillifolia | Scheele | Onagraceae | 8 |
| Oenothera cespitosa | Nutt. | Onagraceae | 8 |
| Oenothera curtiflora | W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera deserticola | (Loes.) Munz | Onagraceae | 8 |
| Oenothera drummondii | Hook. | Onagraceae | 8 |
| Oenothera elata | Kunth | Onagraceae | 8 |
| Oenothera epilobiifolia | Kunth | Onagraceae | 8 |
| Oenothera flava | (A.Nelson) Garrett | Onagraceae | 8 |
| Oenothera glaucifolia | W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera grandis | Smyth | Onagraceae | 8 |
| Oenothera hartwegii | Benth. | Onagraceae | 8 |
| Oenothera hexandra | (Ortega) W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera jamesii | Torr. & A.Gray | Onagraceae | 8 |
| Oenothera kunthiana | (Spach) Munz | Onagraceae | 8 |
| Oenothera laciniata | Hill | Onagraceae | 8 |
| Oenothera lavandulifolia | Torr. & A.Gray | Onagraceae | 8 |
| Oenothera macrocarpa | Nutt. | Onagraceae | 8 |
| Oenothera mckelveyae | (Munz) W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera pallida | Lindl. | Onagraceae | 8 |
| Oenothera podocarpa | (Wooton & Standl.) Krakos & W.L.Wagner | Onagraceae | 8 |
| Oenothera primiveris | A.Gray | Onagraceae | 8 |
| Oenothera pubescens | Wild. ex Spreng. | Onagraceae | 8 |
| Oenothera rosea | Aiton | Onagraceae | 8 |
| Oenothera serrulata | Nutt. | Onagraceae | 8 |
| Oenothera speciosa | Nutt. | Onagraceae | 8 |
| Oenothera suffrutescens | (Ser.) W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera tetraptera | Cav. | Onagraceae | 8 |
| Oenothera toumeyi | (Small) Tidestr. | Onagraceae | 8 |
| Oenothera triloba | Nutt. | Onagraceae | 8 |
| Oenothera tubicula | A.Gray | Onagraceae | 8 |
| Okenia hypogaea | Schltdl. & Cham. | Nyctaginaceae | 8 |
| Oligomeris linifolia | (Vahl ex Hornem.) J.F.Macbr. | Resedaceae | 8 |
| Oncidium graminifolium | (Lindl.) Lindl. | Orchidaceae | 8 |
| Oncidium sphacelatum | Lindl. | Orchidaceae | 8 |
| Operculina pinnatifida | (Kunth) O'Donell | Convolvulaceae | 8 |
| Operculina pteripes | (G.Don) O'Donell | Convolvulaceae | 8 |
| Ophioglossum californicum | Prantl | Ophioglossaceae | 8 |
| Ophioglossum crotalophoroides | Walter | Ophioglossaceae | 8 |
| Ophioglossum engelmannii | Prantl | Ophioglossaceae | 8 |
| Ophioglossum polyphyllum | A.Braun ex Seub. | Ophioglossaceae | 8 |
| Ophioglossum vulgatum | L. | Ophioglossaceae | 8 |
| Oplismenus compositus | (L.) P.Beauv. | Poaceae | 8 |
| Oplismenus hirtellus | (L.) P.Beauv. | Poaceae | 8 |
| Opuntia arenaria | Engelm. | Cactaceae | 8 |
| Opuntia azurea | Rose | Cactaceae | 8 |
| Opuntia chisosensis | (M.S.Anthony) D.J.Ferguson | Cactaceae | 8 |
| Opuntia chlorotica | Engelm. & J.M.Bigelow | Cactaceae | 8 |
| Opuntia cochenillifera | (L.) Mill. | Cactaceae | 8 |
| Opuntia decumbens | Salm-Dyck | Cactaceae | 8 |
| Opuntia dejecta | Salm-Dyck | Cactaceae | 8 |
| Opuntia engelmannii | Salm-Dyck ex Engelm. | Cactaceae | 8 |
| Opuntia ficus-indica | (L.) Mill. | Cactaceae | 8 |
| Opuntia humifusa | (Raf.) Raf. | Cactaceae | 8 |
| Opuntia hyptiacantha | F.A.C.Weber | Cactaceae | 8 |
| Opuntia jaliscana | Bravo | Cactaceae | 8 |
| Opuntia leucotricha | DC. | Cactaceae | 8 |
| Opuntia macrocentra | Engelm. | Cactaceae | 8 |
| Opuntia macrorhiza | Engelm. | Cactaceae | 8 |
| Opuntia microdasys | (Lehm.) Pfeiff. | Cactaceae | 8 |
| Opuntia orbiculata | Salm-Dyck ex Pfeiff. | Cactaceae | 8 |
| Opuntia phaeacantha | Engelm. | Cactaceae | 8 |
| Opuntia polyacantha | Haw. | Cactaceae | 8 |
| Opuntia pottsii | Salm-Dyck | Cactaceae | 8 |
| Opuntia puberula | Pfeiff. | Cactaceae | 8 |
| Opuntia pubescens | H.L.Wendl. ex Pfeiff. | Cactaceae | 8 |
| Opuntia rastrera | F.A.C.Weber | Cactaceae | 8 |
| Opuntia robusta | Pfeiff. | Cactaceae | 8 |
| Opuntia rufida | Engelm. | Cactaceae | 8 |
| Opuntia stenopetala | Engelm. | Cactaceae | 8 |
| Opuntia streptacantha | Lem. | Cactaceae | 8 |
| Opuntia stricta | (Haw.) Haw. | Cactaceae | 8 |
| Opuntia strigil | Engelm. | Cactaceae | 8 |
| Opuntia tomentosa | Salm-Dyck | Cactaceae | 8 |
| Oreocarya oblata | (M.E.Jones) J.F.Macbr. | Boraginaceae | 8 |
| Oreocarya palmeri | (A.Gray) Greene | Boraginaceae | 8 |
| Oreocarya suffruticosa | (Torr.) Greene | Boraginaceae | 8 |
| Oreochrysum parryi | Rydb. | Asteraceae | 8 |
| Oreopanax peltatus | Linden ex Regel | Araliaceae | 8 |
| Orobanche cooperi | (A.Gray) A.Heller | Orobanchaceae | 8 |
| Orobanche dugesii | (S.Watson) Munz | Orobanchaceae | 8 |
| Orobanche fasciculata | Nutt. | Orobanchaceae | 8 |
| Orobanche ludoviciana | Nutt. | Orobanchaceae | 8 |
| Orthilia secunda | (L.) House | Ericaceae | 8 |
| Orthosphenia mexicana | Standl. | Celastraceae | 8 |
| Osbertia stolonifera | Greene | Asteraceae | 8 |
| Osmunda spectabilis | Willd. | Osmundaceae | 8 |
| Ostrya virginiana | (Mill.) K.Koch | Betulaceae | 8 |
| Otatea acuminata | (Munro) C.E.Calderón ex Soderstr. | Poaceae | 8 |
| Oxalis alpina | (Rose) Rose ex R.Knuth | Oxalidaceae | 8 |
| Oxalis caerulea | (Small) R.Knuth | Oxalidaceae | 8 |
| Oxalis decaphylla | Kunth | Oxalidaceae | 8 |
| Oxalis dichondrifolia | A.Gray | Oxalidaceae | 8 |
| Oxalis dillenii | Jacq. | Oxalidaceae | 8 |
| Oxalis drummondii | A.Gray | Oxalidaceae | 8 |
| Oxalis frutescens | L. | Oxalidaceae | 8 |
| Oxalis latifolia | Kunth | Oxalidaceae | 8 |
| Oxalis macrantha | (Trel.) Small | Oxalidaceae | 8 |
| Oxalis nelsonii | (Small) R.Knuth | Oxalidaceae | 8 |
| Oxalis pilosa | Nutt. | Oxalidaceae | 8 |
| Oxalis rhombifolia | Jacq. | Oxalidaceae | 8 |
| Oxalis stricta | L. | Oxalidaceae | 8 |
| Oxalis tetraphylla | Cav. | Oxalidaceae | 8 |
| Oxalis violacea | L. | Oxalidaceae | 8 |
| Oxybaphus nyctagineus | (Michx.) Sweet | Nyctaginaceae | 8 |
| Oxypetalum cordifolium | (Vent.) Schltr. | Apocynaceae | 8 |
| Pachycereus pecten-aboriginum | (Engelm. ex S.Watson) Britton & Rose | Cactaceae | 8 |
| Pachycereus pringlei | (S.Watson) Britton & Rose | Cactaceae | 8 |
| Pachycereus weberi | (J.M.Coult.) Backeb. | Cactaceae | 8 |
| Pachyrhizus erosus | (L.) Urb. | Fabaceae | 8 |
| Packera coahuilensis | (Greenm.) C.Jeffrey | Asteraceae | 8 |
| Packera montereyana | (S.Watson) C.Jeffrey | Asteraceae | 8 |
| Packera neomexicana | (A.Gray) W.A.Weber & Á.Löve | Asteraceae | 8 |
| Packera sanguisorbae | (DC.) C.Jeffrey | Asteraceae | 8 |
| Packera tampicana | (DC.) C.Jeffrey | Asteraceae | 8 |
| Painteria elachistophylla | (A.Gray ex S.Watson) Britton & Rose | Fabaceae | 8 |
| Palafoxia arida | B.L.Turner & M.I.Morris | Asteraceae | 8 |
| Palafoxia callosa | (Nutt.) Torr. & A.Gray | Asteraceae | 8 |
| Palafoxia sphacelata | (Nutt. ex Torr.) Cory | Asteraceae | 8 |
| Palafoxia texana | DC. | Asteraceae | 8 |
| Palhinhaea cernua | (L.) Vasc. & Franco | Lycopodiaceae | 8 |
| Palicourea galeottiana | M.Martens | Rubiaceae | 8 |
| Palicourea padifolia | (Willd. ex Schult.) C.M.Taylor & Lorence | Rubiaceae | 8 |
| Palicourea pubescens | (Sw.) Borhidi | Rubiaceae | 8 |
| Palicourea tetragona | (Donn.Sm.) C.M.Taylor | Rubiaceae | 8 |
| Panicum amarum | Elliott | Poaceae | 8 |
| Panicum capillare | L. | Poaceae | 8 |
| Panicum capillarioides | Vasey | Poaceae | 8 |
| Panicum dichotomiflorum | Michx. | Poaceae | 8 |
| Panicum hallii | Vasey | Poaceae | 8 |
| Panicum hirticaule | J.Presl | Poaceae | 8 |
| Panicum virgatum | L. | Poaceae | 8 |
| Pappophorum bicolor | E.Fourn. | Poaceae | 8 |
| Pappophorum mucronulatum | Nees | Poaceae | 8 |
| Pappophorum pappiferum | (Lam.) Kuntze | Poaceae | 8 |
| Parathesis leptopa | Lundell | Primulaceae | 8 |
| Parietaria floridana | Nutt. | Urticaceae | 8 |
| Parietaria pensylvanica | Muhl. ex Willd. | Urticaceae | 8 |
| Parkinsonia aculeata | L. | Fabaceae | 8 |
| Parkinsonia florida | (Benth. ex A.Gray) S.Watson | Fabaceae | 8 |
| Parkinsonia praecox | (Ruiz & Pav.) Hawkins | Fabaceae | 8 |
| Parkinsonia texana | (A.Gray) S.Watson | Fabaceae | 8 |
| Paronychia jamesii | Torr. & A.Gray | Caryophyllaceae | 8 |
| Paronychia monticola | Cory | Caryophyllaceae | 8 |
| Paronychia virginica | Spreng. | Caryophyllaceae | 8 |
| Parthenium confertum | A.Gray | Asteraceae | 8 |
| Parthenium hysterophorus | L. | Asteraceae | 8 |
| Parthenium incanum | Kunth | Asteraceae | 8 |
| Parthenocissus quinquefolia | (L.) Planch. | Vitaceae | 8 |
| Paspalum conjugatum | P.J.Bergius | Poaceae | 8 |
| Paspalum denticulatum | Trin. | Poaceae | 8 |
| Paspalum distichum | L. | Poaceae | 8 |
| Paspalum langei | (E.Fourn.) Nash | Poaceae | 8 |
| Paspalum paniculatum | L. | Poaceae | 8 |
| Paspalum plicatulum | Michx. | Poaceae | 8 |
| Paspalum pubiflorum | Rupr. ex E.Fourn. | Poaceae | 8 |
| Paspalum setaceum | Michx. | Poaceae | 8 |
| Paspalum vaginatum | Sw. | Poaceae | 8 |
| Passiflora adenopoda | DC. | Passifloraceae | 8 |
| Passiflora affinis | Engelm. | Passifloraceae | 8 |
| Passiflora biflora | Lam. | Passifloraceae | 8 |
| Passiflora bryonioides | Kunth | Passifloraceae | 8 |
| Passiflora capsularis | L. | Passifloraceae | 8 |
| Passiflora exsudans | Zucc. | Passifloraceae | 8 |
| Passiflora filipes | Benth. | Passifloraceae | 8 |
| Passiflora foetida | L. | Passifloraceae | 8 |
| Passiflora lanuginosa | (Killip) H.T.Svoboda | Passifloraceae | 8 |
| Passiflora mexicana | Juss. | Passifloraceae | 8 |
| Passiflora pallida | L. | Passifloraceae | 8 |
| Passiflora sexflora | Juss. | Passifloraceae | 8 |
| Passiflora sexocellata | Schltdl. | Passifloraceae | 8 |
| Passiflora suberosa | L. | Passifloraceae | 8 |
| Passiflora subpeltata | Ortega | Passifloraceae | 8 |
| Passiflora tenuiloba | Engelm. | Passifloraceae | 8 |
| Passiflora zapalinamensis | Kuethe, Encina & Cruz-Anaya | Passifloraceae | 8 |
| Paullinia costata | Schltdl. & Cham. | Sapindaceae | 8 |
| Paullinia fuscescens | Kunth | Sapindaceae | 8 |
| Paullinia pinnata | L. | Sapindaceae | 8 |
| Pavonia lasiopetala | Scheele | Malvaceae | 8 |
| Pavonia oxyphylla | (DC.) Fryxell | Malvaceae | 8 |
| Pavonia schiedeana | Steud. | Malvaceae | 8 |
| Paxistima myrsinites | (Pursh) Raf. | Celastraceae | 8 |
| Pectis angustifolia | Torr. | Asteraceae | 8 |
| Pectis cylindrica | Rydb. | Asteraceae | 8 |
| Pectis filipes | Harv. & Gray | Asteraceae | 8 |
| Pectis multiflosculosa | (DC.) Sch.Bip. | Asteraceae | 8 |
| Pectis papposa | Harv. & Gray | Asteraceae | 8 |
| Pectis prostrata | Cav. | Asteraceae | 8 |
| Pedicularis canadensis | L. | Orobanchaceae | 8 |
| Pedicularis mexicana | Zucc. ex Benth. | Orobanchaceae | 8 |
| Pediomelum pentaphyllum | (L.) Rydb. | Fabaceae | 8 |
| Pediomelum rhombifolium | (Torr. & A.Gray) Rydb. | Fabaceae | 8 |
| Pediomelum tenuiflorum | (Pursh) A.N.Egan | Fabaceae | 8 |
| Peganum mexicanum | A.Gray | Nitrariaceae | 8 |
| Pelazoneuron kunthii | (Desv.) A.R.Sm. & S.E.Fawc. | Thelypteridaceae | 8 |
| Pelazoneuron ovatum | (R.P.St.John) A.R.Sm. & S.E.Fawc. | Thelypteridaceae | 8 |
| Pelazoneuron puberulum | (Baker) A.R.Sm. & S.E.Fawc. | Thelypteridaceae | 8 |
| Pelecyphora aselliformis | C.Ehrenb. | Cactaceae | 8 |
| Pelecyphora dasyacantha | (Engelm.) D.Aquino & Dan.Sánchez | Cactaceae | 8 |
| Pelecyphora emskoetteriana | (Quehl) D.Aquino & Dan.Sánchez | Cactaceae | 8 |
| Pelecyphora lloydii | (Britton & Rose) D.Aquino & Dan.Sánchez | Cactaceae | 8 |
| Pelecyphora macromeris | (Engelm.) D.Aquino & Dan.Sánchez | Cactaceae | 8 |
| Pelecyphora missouriensis | (Sweet) D.Aquino & Dan.Sánchez | Cactaceae | 8 |
| Pelecyphora tuberculosa | (Engelm.) D.Aquino & Dan.Sánchez | Cactaceae | 8 |
| Pelecyphora vivipara | (Nutt.) D.Aquino & Dan.Sánchez | Cactaceae | 8 |
| Pellaea atropurpurea | (L.) Link | Pteridaceae | 8 |
| Pellaea intermedia | Mett. | Pteridaceae | 8 |
| Pellaea ternifolia | (Cav.) Link | Pteridaceae | 8 |
| Pellaea wrightiana | Hook. | Pteridaceae | 8 |
| Peniocereus greggii | (Engelm.) Britton & Rose | Cactaceae | 8 |
| Peniocereus striatus | (Brandegee) Buxb. | Cactaceae | 8 |
| Pennellia longifolia | (Benth.) Rollins | Brassicaceae | 8 |
| Penstemon ambiguus | Torr. | Plantaginaceae | 8 |
| Penstemon baccharifolius | Hook. | Plantaginaceae | 8 |
| Penstemon barbatus | (Cav.) Roth | Plantaginaceae | 8 |
| Penstemon campanulatus | (Cav.) Willd. | Plantaginaceae | 8 |
| Penstemon dasyphyllus | A.Gray | Plantaginaceae | 8 |
| Penstemon fendleri | Torr. & A.Gray | Plantaginaceae | 8 |
| Penstemon gentianoides | (Kunth) Poir. | Plantaginaceae | 8 |
| Penstemon glaber | Pursh | Plantaginaceae | 8 |
| Penstemon havardii | A.Gray | Plantaginaceae | 8 |
| Penstemon jamesii | Benth. | Plantaginaceae | 8 |
| Penstemon lanceolatus | Benth. | Plantaginaceae | 8 |
| Penstemon leonensis | Straw | Plantaginaceae | 8 |
| Penstemon neomexicanus | Wooton & Standl. | Plantaginaceae | 8 |
| Penstemon parryi | A.Gray | Plantaginaceae | 8 |
| Penstemon pinifolius | Greene | Plantaginaceae | 8 |
| Penstemon roseus | (Cerv. ex Sweet) G.Don | Plantaginaceae | 8 |
| Penstemon secundiflorus | Benth. | Plantaginaceae | 8 |
| Penstemon superbus | A.Nelson | Plantaginaceae | 8 |
| Penstemon thurberi | Torr. | Plantaginaceae | 8 |
| Penstemon triflorus | A.Heller | Plantaginaceae | 8 |
| Penstemon virgatus | A.Gray | Plantaginaceae | 8 |
| Peperomia bracteata | A.W.Hill | Piperaceae | 8 |
| Peperomia galioides | Kunth | Piperaceae | 8 |
| Peperomia glabella | (Sw.) A.Dietr. | Piperaceae | 8 |
| Peperomia maculosa | (L.) Hook. | Piperaceae | 8 |
| Peperomia obtusifolia | (L.) A.Dietr. | Piperaceae | 8 |
| Peperomia quadrifolia | (L.) Kunth | Piperaceae | 8 |
| Peperomia rotundifolia | (L.) Kunth | Piperaceae | 8 |
| Peperomia tetraphylla | (G.Forst.) Hook. & Arn. | Piperaceae | 8 |
| Pereskiopsis diguetii | (F.A.C.Weber) Britton & Rose | Cactaceae | 8 |
| Pereskiopsis porteri | (K.Brandegee ex F.A.C.Weber) Britton & Rose | Cactaceae | 8 |
| Pericome caudata | A.Gray | Asteraceae | 8 |
| Periptera punicea | (Lag.) DC. | Malvaceae | 8 |
| Perityle emoryi | Torr. | Asteraceae | 8 |
| Perityle lemmonii | (A.Gray) J.F.Macbr. | Asteraceae | 8 |
| Perityle microglossa | Benth. | Asteraceae | 8 |
| Persicaria acuminata | (Kunth) M.Gómez | Polygonaceae | 8 |
| Persicaria amphibia | (L.) Delarbre | Polygonaceae | 8 |
| Persicaria glabra | (Willd.) M.Gómez | Polygonaceae | 8 |
| Persicaria hydropiperoides | (Michx.) Small | Polygonaceae | 8 |
| Persicaria pensylvanica | (L.) M.Gómez | Polygonaceae | 8 |
| Persicaria punctata | Small | Polygonaceae | 8 |
| Persicaria setacea | Small | Polygonaceae | 8 |
| Perymenium buphthalmoides | DC. | Asteraceae | 8 |
| Perymenium gymnolomoides | (Less.) DC. | Asteraceae | 8 |
| Perymenium mendezii | DC. | Asteraceae | 8 |
| Peteravenia schultzii | (Schnittsp.) R.M.King & H.Rob. | Asteraceae | 8 |
| Peteria scoparia | A.Gray | Fabaceae | 8 |
| Petiveria alliacea | L. | Petiveriaceae | 8 |
| Petrea volubilis | L. | Verbenaceae | 8 |
| Petrophytum caespitosum | (Nutt.) Rydb. | Rosaceae | 8 |
| Phacelia alba | Rydb. | Hydrophyllaceae | 8 |
| Phacelia coerulea | Greene | Hydrophyllaceae | 8 |
| Phacelia congesta | Hook. | Hydrophyllaceae | 8 |
| Phacelia corrugata | A.Nelson | Hydrophyllaceae | 8 |
| Phacelia distans | Benth. | Hydrophyllaceae | 8 |
| Phacelia dubia | (L.) Trel. | Hydrophyllaceae | 8 |
| Phacelia heterophylla | Pursh | Hydrophyllaceae | 8 |
| Phacelia infundibuliformis | Torr. | Hydrophyllaceae | 8 |
| Phacelia integrifolia | Torr. | Hydrophyllaceae | 8 |
| Phacelia patuliflora | (Engelm. & A.Gray) A.Gray | Hydrophyllaceae | 8 |
| Phacelia platycarpa | (Cav.) Spreng. | Hydrophyllaceae | 8 |
| Phacelia popei | Torr. & A.Gray | Hydrophyllaceae | 8 |
| Phacelia rupestris | Greene | Hydrophyllaceae | 8 |
| Phacelia secunda | J.F.Gmel. | Hydrophyllaceae | 8 |
| Phalaris arundinacea | L. | Poaceae | 8 |
| Phalaris caroliniana | Walter | Poaceae | 8 |
| Phanerophlebia umbonata | Underw. | Dryopteridaceae | 8 |
| Pharus lappulaceus | Aubl. | Poaceae | 8 |
| Phaseolus angustissimus | A.Gray | Fabaceae | 8 |
| Phaseolus coccineus | L. | Fabaceae | 8 |
| Phaseolus filiformis | Benth. | Fabaceae | 8 |
| Phaseolus grayanus | Wooton & Standl. | Fabaceae | 8 |
| Phaseolus lunatus | L. | Fabaceae | 8 |
| Phaseolus microcarpus | Mart. | Fabaceae | 8 |
| Phaseolus parvulus | Greene | Fabaceae | 8 |
| Phaseolus vulgaris | L. | Fabaceae | 8 |
| Phaulothamnus spinescens | A.Gray | Achatocarpaceae | 8 |
| Phemeranthus brevicaulis | (S.Watson) Kiger | Montiaceae | 8 |
| Phemeranthus calycinus | (Engelm.) Kiger | Montiaceae | 8 |
| Phemeranthus napiformis | (DC.) Ocampo | Montiaceae | 8 |
| Phemeranthus parviflorus | (Nutt.) Kiger | Montiaceae | 8 |
| Phenax hirtus | (Sw.) Wedd. | Urticaceae | 8 |
| Phenax rugosus | (Poir.) Wedd. | Urticaceae | 8 |
| Philadelphus mexicanus | Schltdl. | Hydrangeaceae | 8 |
| Philadelphus microphyllus | A.Gray | Hydrangeaceae | 8 |
| Philadelphus texensis | S.Y.Hu | Hydrangeaceae | 8 |
| Philodendron anisotomum | Schott | Araceae | 8 |
| Philodendron hederaceum | (Jacq.) Schott | Araceae | 8 |
| Philodendron jacquinii | Schott | Araceae | 8 |
| Philodendron radiatum | Schott | Araceae | 8 |
| Phlebodium decumanum | (Willd.) J.Sm. | Polypodiaceae | 8 |
| Phlebodium pseudoaureum | (Cav.) Lellinger | Polypodiaceae | 8 |
| Phleum alpinum | L. | Poaceae | 8 |
| Phlox nana | Nutt. | Polemoniaceae | 8 |
| Phlox pilosa | L. | Polemoniaceae | 8 |
| Phoradendron bolleanum | (Seem.) Eichler | Santalaceae | 8 |
| Phoradendron brachystachyum | (DC.) Nutt. | Santalaceae | 8 |
| Phoradendron capitellatum | Torr. ex Trel. | Santalaceae | 8 |
| Phoradendron carneum | Urb. | Santalaceae | 8 |
| Phoradendron coryae | Trel. | Santalaceae | 8 |
| Phoradendron densum | Torr. ex Trel. | Santalaceae | 8 |
| Phoradendron hawksworthii | Wiens | Santalaceae | 8 |
| Phoradendron juniperinum | Engelm. ex A.Gray | Santalaceae | 8 |
| Phoradendron leucarpum | (Raf.) Reveal & M.C.Johnst. | Santalaceae | 8 |
| Phoradendron macrophyllum | (Engelm.) Cockerell | Santalaceae | 8 |
| Phoradendron quadrangulare | (Kunth) Griseb. | Santalaceae | 8 |
| Photinia arbutifolia | Lindl. | Rosaceae | 8 |
| Phragmites australis | (Cav.) Steud. | Poaceae | 8 |
| Phryma leptostachya | L. | Phrymaceae | 8 |
| Phyla cuneifolia | (Torr.) Greene | Verbenaceae | 8 |
| Phyla lanceolata | (Michx.) Greene | Verbenaceae | 8 |
| Phyla nodiflora | (L.) Greene | Verbenaceae | 8 |
| Phyllanthopsis phyllanthoides | (Nutt.) Voronts. & Petra Hoffm. | Phyllanthaceae | 8 |
| Phyllanthus abnormis | Baill. | Phyllanthaceae | 8 |
| Phyllanthus caroliniensis | Walter | Phyllanthaceae | 8 |
| Phyllanthus evanescens | Brandegee | Phyllanthaceae | 8 |
| Phyllanthus grandifolius | L. | Phyllanthaceae | 8 |
| Phyllanthus niruri | L. | Phyllanthaceae | 8 |
| Phyllanthus polygonoides | Nutt. ex Spreng. | Phyllanthaceae | 8 |
| Phyllanthus warnockii | G.L.Webster | Phyllanthaceae | 8 |
| Physalis acutifolia | (Miers) Sandwith | Solanaceae | 8 |
| Physalis angulata | L. | Solanaceae | 8 |
| Physalis campechiana | L. | Solanaceae | 8 |
| Physalis cinerascens | (Dunal) Hitchc. | Solanaceae | 8 |
| Physalis cordata | Mill. | Solanaceae | 8 |
| Physalis fendleri | A.Gray | Solanaceae | 8 |
| Physalis hederifolia | A.Gray | Solanaceae | 8 |
| Physalis longifolia | Nutt. | Solanaceae | 8 |
| Physalis melanocystis | (B.L.Rob.) Bitter | Solanaceae | 8 |
| Physalis mollis | Nutt. | Solanaceae | 8 |
| Physalis nicandroides | Schltdl. | Solanaceae | 8 |
| Physalis patula | Mill. | Solanaceae | 8 |
| Physalis philadelphica | Lam. | Solanaceae | 8 |
| Physalis pubescens | L. | Solanaceae | 8 |
| Physalis solanacea | (Schltdl.) Axelius | Solanaceae | 8 |
| Physalis sulphurea | (Fernald) Waterf. | Solanaceae | 8 |
| Physalis virginiana | Mill. | Solanaceae | 8 |
| Physalis viscosa | L. | Solanaceae | 8 |
| Physalis walteri | Nutt. | Solanaceae | 8 |
| Physaria fendleri | (A.Gray) O'Kane & Al-Shehbaz | Brassicaceae | 8 |
| Physaria gordonii | (A.Gray) O'Kane & Al-Shehbaz | Brassicaceae | 8 |
| Physaria purpurea | (A.Gray) O'Kane & Al-Shehbaz | Brassicaceae | 8 |
| Physocarpus intermedius | (Rydb.) C.K.Schneid. | Rosaceae | 8 |
| Physodium adenodes | (Goldberg) Fryxell | Malvaceae | 8 |
| Physostegia virginiana | (L.) Benth. | Lamiaceae | 8 |
| Phytolacca americana | L. | Phytolaccaceae | 8 |
| Phytolacca heterotepala | H.Walter | Phytolaccaceae | 8 |
| Phytolacca icosandra | L. | Phytolaccaceae | 8 |
| Phytolacca octandra | L. | Phytolaccaceae | 8 |
| Phytolacca rivinoides | Kunth & C.D.Bouché | Phytolaccaceae | 8 |
| Phytolacca rugosa | A.Braun & C.D.Bouché | Phytolaccaceae | 8 |
| Picea chihuahuana | Martínez | Pinaceae | 8 |
| Picea engelmannii | Parry ex Engelm. | Pinaceae | 8 |
| Picradeniopsis absinthifolia | (Benth.) B.G.Baldwin | Asteraceae | 8 |
| Picradeniopsis multiflora | (Hook. & Arn.) B.G.Baldwin | Asteraceae | 8 |
| Picramnia antidesma | Sw. | Picramniaceae | 8 |
| Pilea imparifolia | Wedd. | Urticaceae | 8 |
| Pilea microphylla | (L.) Liebm. | Urticaceae | 8 |
| Pilosocereus leucocephalus | (Poselg.) Byles & G.D.Rowley | Cactaceae | 8 |
| Pilosocereus purpusii | (Britton & Rose) Byles & G.D.Rowley | Cactaceae | 8 |
| Pilostyles thurberi | A.Gray | Apodanthaceae | 8 |
| Pinaropappus roseus | (Less.) Less. | Asteraceae | 8 |
| Pinguicula debbertiana | Speta & F.Fuchs | Lentibulariaceae | 8 |
| Pinguicula moranensis | Kunth | Lentibulariaceae | 8 |
| Pinguicula oblongiloba | A.DC. | Lentibulariaceae | 8 |
| Pinguicula parvifolia | B.L.Rob. | Lentibulariaceae | 8 |
| Pinus arizonica | Engelm. | Pinaceae | 8 |
| Pinus ayacahuite | Ehrenb. ex Schltdl. | Pinaceae | 8 |
| Pinus cembroides | Zucc. | Pinaceae | 8 |
| Pinus culminicola | Andresen & Beaman | Pinaceae | 8 |
| Pinus devoniana | Lindl. | Pinaceae | 8 |
| Pinus durangensis | Martínez | Pinaceae | 8 |
| Pinus engelmannii | Carrière | Pinaceae | 8 |
| Pinus flexilis | E.James | Pinaceae | 8 |
| Pinus greggii | Engelm. ex Parl. | Pinaceae | 8 |
| Pinus hartwegii | Lindl. | Pinaceae | 8 |
| Pinus herrerae | Mast. | Pinaceae | 8 |
| Pinus leiophylla | Schiede ex Schltdl. & Cham. | Pinaceae | 8 |
| Pinus lumholtzii | B.L.Rob. & Fernald | Pinaceae | 8 |
| Pinus maximartinezii | Rzed. | Pinaceae | 8 |
| Pinus maximinoi | H.E.Moore | Pinaceae | 8 |
| Pinus montezumae | Lamb. | Pinaceae | 8 |
| Pinus nelsonii | Shaw | Pinaceae | 8 |
| Pinus oocarpa | Schiede | Pinaceae | 8 |
| Pinus patula | Schiede ex Schltdl. & Cham. | Pinaceae | 8 |
| Pinus pinceana | Gordon | Pinaceae | 8 |
| Pinus pseudostrobus | Lindl. | Pinaceae | 8 |
| Pinus remota | (Little) D.K.Bailey & Hawksw. | Pinaceae | 8 |
| Pinus strobiformis | Engelm. | Pinaceae | 8 |
| Pinus stylesii | Frankis ex Businsky | Pinaceae | 8 |
| Pinus teocote | Schied. ex Schltdl. & Cham. | Pinaceae | 8 |
| Piper aduncum | L. | Piperaceae | 8 |
| Piper amalago | L. | Piperaceae | 8 |
| Piper auritum | Kunth | Piperaceae | 8 |
| Piper hispidum | Sw. | Piperaceae | 8 |
| Piper peltatum | L. | Piperaceae | 8 |
| Piper tuberculatum | Jacq. | Piperaceae | 8 |
| Piper umbellatum | L. | Piperaceae | 8 |
| Piptochaetium avenaceum | (L.) Parodi | Poaceae | 8 |
| Piptochaetium fimbriatum | (Kunth) Hitchc. | Poaceae | 8 |
| Piptochaetium pringlei | (Beal) Parodi | Poaceae | 8 |
| Piqueria trinervia | Cav. | Asteraceae | 8 |
| Piscidia carthagenensis | Jacq. | Fabaceae | 8 |
| Piscidia piscipula | (L.) Sarg. | Fabaceae | 8 |
| Pisonia aculeata | L. | Nyctaginaceae | 8 |
| Pisonia capitata | (S.Watson) Standl. | Nyctaginaceae | 8 |
| Pisoniella arborescens | (Lag. & Rodr.) Standl. | Nyctaginaceae | 8 |
| Pistacia mexicana | Kunth | Anacardiaceae | 8 |
| Pistia stratiotes | L. | Araceae | 8 |
| Pithecellobium dulce | (Roxb.) Benth. | Fabaceae | 8 |
| Pithecellobium lanceolatum | (Humb. & Bonpl. ex Willd.) Benth. | Fabaceae | 8 |
| Pithecellobium unguis-cati | (L.) Benth. | Fabaceae | 8 |
| Pittocaulon velatum | (Greenm.) H.Rob. & Brettell | Asteraceae | 8 |
| Pityopsis graminifolia | (Michx.) Nutt. | Asteraceae | 8 |
| Pityrogramma calomelanos | (L.) Link | Pteridaceae | 8 |
| Pityrogramma trifoliata | (L.) R.M.Tryon | Pteridaceae | 8 |
| Plantago australis | Lam. | Plantaginaceae | 8 |
| Plantago helleri | Small | Plantaginaceae | 8 |
| Plantago hookeriana | Fisch. & C.A.Mey. | Plantaginaceae | 8 |
| Plantago nivea | Kunth | Plantaginaceae | 8 |
| Plantago ovata | Forssk. | Plantaginaceae | 8 |
| Plantago patagonica | Jacq. | Plantaginaceae | 8 |
| Plantago rhodosperma | Decne. | Plantaginaceae | 8 |
| Plantago sericea | Ruiz & Pav. | Plantaginaceae | 8 |
| Plantago virginica | L. | Plantaginaceae | 8 |
| Plantago wrightiana | Decne. | Plantaginaceae | 8 |
| Platanthera brevifolia | (Greene) Senghas | Orchidaceae | 8 |
| Platanus mexicana | Moric. | Platanaceae | 8 |
| Platanus rzedowskii | Nixon & J.M.Poole | Platanaceae | 8 |
| Platanus wrightii | S.Watson | Platanaceae | 8 |
| Platymiscium trifoliolatum | Benth. | Fabaceae | 8 |
| Plectocephalus americanus | (Nutt.) D.Don | Asteraceae | 8 |
| Pleopeltis angusta | Humb. & Bonpl. ex Willd. | Polypodiaceae | 8 |
| Pleopeltis crassinervata | T.Moore | Polypodiaceae | 8 |
| Pleopeltis guttata | (Maxon) E.G.Andrews & Windham | Polypodiaceae | 8 |
| Pleopeltis macrocarpa | (Bory ex Willd.) Kaulf. | Polypodiaceae | 8 |
| Pleopeltis michauxiana | (Weath.) Hickey & Sprunt | Polypodiaceae | 8 |
| Pleopeltis plebeia | (Schltdl. & Cham.) A.R.Sm. & Tejero | Polypodiaceae | 8 |
| Pleopeltis polylepis | (A.Roem. ex Kunze) T.Moore | Polypodiaceae | 8 |
| Pleopeltis polypodioides | (L.) E.G.Andrews & Windham | Polypodiaceae | 8 |
| Pleuranthodendron lindenii | (Turcz.) Sleumer | Salicaceae | 8 |
| Pleuropetalum sprucei | (Hook.f.) Standl. | Amaranthaceae | 8 |
| Pleurothallis ruscifolia | (Jacq.) R.Br. | Orchidaceae | 8 |
| Pluchea carolinensis | (Jacq.) G.Don | Asteraceae | 8 |
| Pluchea odorata | (L.) Cass. | Asteraceae | 8 |
| Pluchea salicifolia | (Mill.) S.F.Blake | Asteraceae | 8 |
| Plumbago pulchella | Boiss. | Plumbaginaceae | 8 |
| Plumbago zeylanica | L. | Plumbaginaceae | 8 |
| Plumeria rubra | L. | Apocynaceae | 8 |
| Poa bigelovii | Vasey ex Scribn. | Poaceae | 8 |
| Poa fendleriana | (Steud.) Vasey | Poaceae | 8 |
| Poa pratensis | L. | Poaceae | 8 |
| Podocarpus matudae | Lundell | Podocarpaceae | 8 |
| Polemonium pauciflorum | S.Watson | Polemoniaceae | 8 |
| Poliomintha incana | (Torr.) A.Gray | Lamiaceae | 8 |
| Poliomintha longiflora | A.Gray | Lamiaceae | 8 |
| Polyclathra cucumerina | Bertol. | Cucurbitaceae | 8 |
| Polygonatum biflorum | (Walter) Elliott | Asparagaceae | 8 |
| Polypodium hesperium | Maxon | Polypodiaceae | 8 |
| Polypodium plesiosorum | Kunze | Polypodiaceae | 8 |
| Polypogon interruptus | Kunth | Poaceae | 8 |
| Polypremum procumbens | L. | Tetrachondraceae | 8 |
| Polystachya foliosa | (Hook.) Rchb.f. | Orchidaceae | 8 |
| Polystemma pilosum | (Benth.) Morillo | Apocynaceae | 8 |
| Polystichum acrostichoides | (Michx.) Schott | Dryopteridaceae | 8 |
| Pomaria glandulosa | Cav. | Fabaceae | 8 |
| Pomaria jamesii | (Torr. & A.Gray) Walp. | Fabaceae | 8 |
| Pomaria melanosticta | S.Schauer | Fabaceae | 8 |
| Pombalia glabra | (Dowell) Paula-Souza | Violaceae | 8 |
| Pombalia verticillata | (Ortega) Paula-Souza | Violaceae | 8 |
| Ponthieva racemosa | (Walter) C.Mohr | Orchidaceae | 8 |
| Populus angustifolia | E.James | Salicaceae | 8 |
| Populus brandegeei | C.K.Schneid. | Salicaceae | 8 |
| Populus deltoides | W.Bartram ex Marshall | Salicaceae | 8 |
| Populus fremontii | S.Watson | Salicaceae | 8 |
| Populus tremuloides | Michx. | Salicaceae | 8 |
| Porlieria angustifolia | (Engelm.) A.Gray | Zygophyllaceae | 8 |
| Porophyllum gracile | Benth. | Asteraceae | 8 |
| Porophyllum linaria | (Cav.) DC. | Asteraceae | 8 |
| Porophyllum punctatum | S.F.Blake | Asteraceae | 8 |
| Porophyllum ruderale | (Jacq.) Cass. | Asteraceae | 8 |
| Porophyllum scoparium | A.Gray | Asteraceae | 8 |
| Portulaca halimoides | L. | Portulacaceae | 8 |
| Portulaca pilosa | L. | Portulacaceae | 8 |
| Portulaca suffrutescens | Engelm. | Portulacaceae | 8 |
| Portulaca umbraticola | Kunth | Portulacaceae | 8 |
| Potamogeton diversifolius | Raf. | Potamogetonaceae | 8 |
| Potamogeton foliosus | Raf. | Potamogetonaceae | 8 |
| Potamogeton illinoensis | Morong | Potamogetonaceae | 8 |
| Potamogeton nodosus | Poir. | Potamogetonaceae | 8 |
| Potamogeton pusillus | L. | Potamogetonaceae | 8 |
| Potentilla concinna | Richardson | Rosaceae | 8 |
| Potentilla ehrenbergiana | Schltdl. | Rosaceae | 8 |
| Potentilla hippiana | Lehm. | Rosaceae | 8 |
| Potentilla queretarensis | Rzed. & Calderón | Rosaceae | 8 |
| Potentilla rivalis | Nutt. | Rosaceae | 8 |
| Potentilla supina | L. | Rosaceae | 8 |
| Potentilla thurberi | A.Gray | Rosaceae | 8 |
| Pouteria sapota | (Jacq.) H.E.Moore & Stearn | Sapotaceae | 8 |
| Pouzolzia occidentalis | (Liebm.) Wedd. | Urticaceae | 8 |
| Prescottia stachyodes | (Sw.) Lindl. | Orchidaceae | 8 |
| Prestonia mexicana | A.DC. | Apocynaceae | 8 |
| Primula pauciflora | (Greene) A.R.Mast & Reveal | Primulaceae | 8 |
| Primula rusbyi | Greene | Primulaceae | 8 |
| Prionosciadium nelsonii | J.M.Coult. & Rose | Apiaceae | 8 |
| Prionosciadium thapsoides | (DC.) Mathias | Apiaceae | 8 |
| Pristimera celastroides | (Kunth) A.C.Sm. | Celastraceae | 8 |
| Priva aspera | Kunth | Verbenaceae | 8 |
| Priva grandiflora | (Ortega) Moldenke | Verbenaceae | 8 |
| Priva lappulacea | (L.) Pers. | Verbenaceae | 8 |
| Priva mexicana | (L.) Pers. | Verbenaceae | 8 |
| Proboscidea althaeifolia | (Benth.) Decne. | Martyniaceae | 8 |
| Proboscidea louisianica | (Mill.) Thell. | Martyniaceae | 8 |
| Proboscidea parviflora | (Wooton) Wooton & Standl. | Martyniaceae | 8 |
| Prosthechea cochleata | (L.) W.E.Higgins | Orchidaceae | 8 |
| Prosthechea livida | (Lindl.) W.E.Higgins | Orchidaceae | 8 |
| Prosthechea michuacana | (Lex.) W.E.Higgins | Orchidaceae | 8 |
| Prosthechea radiata | (Lindl.) W.E.Higgins | Orchidaceae | 8 |
| Prosthechea varicosa | (Bateman ex Lindl.) W.E.Higgins | Orchidaceae | 8 |
| Prunella vulgaris | L. | Lamiaceae | 8 |
| Prunus havardii | (W.Wight) S.C.Mason | Rosaceae | 8 |
| Prunus mexicana | S.Watson | Rosaceae | 8 |
| Prunus minutiflora | Engelm. ex A.Gray | Rosaceae | 8 |
| Prunus rhamnoides | Koehne | Rosaceae | 8 |
| Prunus serotina | Ehrh. | Rosaceae | 8 |
| Prunus tetradenia | Koehne | Rosaceae | 8 |
| Psacalium decompositum | (A.Gray) H.Rob. & Brettell | Asteraceae | 8 |
| Psacalium peltatum | Cass. | Asteraceae | 8 |
| Psacalium platylepis | (B.L.Rob. & Seaton) H.Rob. & Brettell | Asteraceae | 8 |
| Psacalium silphiifolium | (B.L.Rob. & Greenm.) H.Rob. & Brettell | Asteraceae | 8 |
| Psacalium sinuatum | (Cerv.) H.Rob. & Brettell | Asteraceae | 8 |
| Psathyrotopsis scaposa | (A.Gray) H.Rob. | Asteraceae | 8 |
| Pseuderanthemum alatum | (Nees) Radlk. | Acanthaceae | 8 |
| Pseuderanthemum cuspidatum | (Nees) Radlk. | Acanthaceae | 8 |
| Pseuderanthemum praecox | (Benth.) Leonard | Acanthaceae | 8 |
| Pseudobombax ellipticum | (Kunth) Dugand | Malvaceae | 8 |
| Pseudobombax palmeri | (S.Watson) Dugand | Malvaceae | 8 |
| Pseudognaphalium attenuatum | (DC.) Anderb. | Asteraceae | 8 |
| Pseudognaphalium biolettii | Anderb. | Asteraceae | 8 |
| Pseudognaphalium canescens | (DC.) Anderb. | Asteraceae | 8 |
| Pseudognaphalium chartaceum | (Greenm.) Anderb. | Asteraceae | 8 |
| Pseudognaphalium leucocephalum | (A.Gray) Anderb. | Asteraceae | 8 |
| Pseudognaphalium roseum | (Kunth) Anderb. | Asteraceae | 8 |
| Pseudognaphalium stramineum | (Kunth) Anderb. | Asteraceae | 8 |
| Pseudogynoxys chenopodioides | (Kunth) Cabrera | Asteraceae | 8 |
| Pseudoroegneria spicata | (Pursh) Á.Löve | Poaceae | 8 |
| Pseudorontium cyathiferum | (Benth.) Rothm. | Plantaginaceae | 8 |
| Pseudosmodingium andrieuxii | Engl. | Anacardiaceae | 8 |
| Pseudotsuga menziesii | (Mirb.) Franco | Pinaceae | 8 |
| Psidium oligospermum | Mart. ex DC. | Myrtaceae | 8 |
| Psiguria triphylla | (Miq.) C.Jeffrey | Cucurbitaceae | 8 |
| Psilactis asteroides | A.Gray | Asteraceae | 8 |
| Psilostrophe gnaphalodes | DC. | Asteraceae | 8 |
| Psilostrophe tagetina | (Nutt.) Greene | Asteraceae | 8 |
| Psilostrophe villosa | Rydb. ex Britton | Asteraceae | 8 |
| Psilotum complanatum | Sw. | Psilotaceae | 8 |
| Psilotum nudum | (L.) P.Beauv. | Psilotaceae | 8 |
| Psittacanthus calyculatus | G.Don | Loranthaceae | 8 |
| Psittacanthus schiedeanus | (Cham. & Schltdl.) G.Don | Loranthaceae | 8 |
| Psorothamnus scoparius | (A.Gray) Rydb. | Fabaceae | 8 |
| Psychotria costivenia | Griseb. | Rubiaceae | 8 |
| Psychotria erythrocarpa | Schltdl. | Rubiaceae | 8 |
| Psychotria limonensis | K.Krause | Rubiaceae | 8 |
| Psychotria mexiae | Standl. | Rubiaceae | 8 |
| Psychotria tenuifolia | Sw. | Rubiaceae | 8 |
| Psychotria trichotoma | M.Martens & Galeotti | Rubiaceae | 8 |
| Ptelea trifoliata | L. | Rutaceae | 8 |
| Pteridium aquilinum | (L.) Kuhn | Dennstaedtiaceae | 8 |
| Pteridium caudatum | (L.) Maxon | Dennstaedtiaceae | 8 |
| Pteridium esculentum | (G.Forst.) Cockayne | Dennstaedtiaceae | 8 |
| Pteris longifolia | L. | Pteridaceae | 8 |
| Pterocaulon virgatum | (L.) DC. | Asteraceae | 8 |
| Pterospora andromedea | Nutt. | Ericaceae | 8 |
| Pterostegia drymarioides | Fisch. & C.A.Mey. | Polygonaceae | 8 |
| Purshia mexicana | (D.Don) S.L.Welsh | Rosaceae | 8 |
| Purshia plicata | (D.Don) Henrickson | Rosaceae | 8 |
| Purshia stansburyana | (Torr.) Henrickson | Rosaceae | 8 |
| Pyrrhopappus carolinianus | (Walter) DC. | Asteraceae | 8 |
| Pyrrhopappus pauciflorus | (D.Don) DC. | Asteraceae | 8 |
| Quercus albocincta | Trel. | Fagaceae | 8 |
| Quercus arizonica | Sarg. | Fagaceae | 8 |
| Quercus calophylla | Schltdl. & Cham. | Fagaceae | 8 |
| Quercus castanea | Née | Fagaceae | 8 |
| Quercus chihuahuensis | Trel. | Fagaceae | 8 |
| Quercus chrysolepis | Liebm. | Fagaceae | 8 |
| Quercus convallata | Trel. | Fagaceae | 8 |
| Quercus crassifolia | Bonpl. | Fagaceae | 8 |
| Quercus deserticola | Trel. | Fagaceae | 8 |
| Quercus eduardi | Trel. | Fagaceae | 8 |
| Quercus emoryi | Torr. | Fagaceae | 8 |
| Quercus fusiformis | Small | Fagaceae | 8 |
| Quercus gambelii | Nutt. | Fagaceae | 8 |
| Quercus germana | Schltdl. & Cham. | Fagaceae | 8 |
| Quercus glaucoides | M.Martens & Galeotti | Fagaceae | 8 |
| Quercus gravesii | Sudw. | Fagaceae | 8 |
| Quercus greggii | (A.DC.) Trel. | Fagaceae | 8 |
| Quercus grisea | Liebm. | Fagaceae | 8 |
| Quercus hypoleucoides | A.Camus | Fagaceae | 8 |
| Quercus hypoxantha | Trel. | Fagaceae | 8 |
| Quercus intricata | Trel. | Fagaceae | 8 |
| Quercus jonesii | Trel. | Fagaceae | 8 |
| Quercus laceyi | Small | Fagaceae | 8 |
| Quercus laeta | Liebm. | Fagaceae | 8 |
| Quercus lancifolia | Schltdl. & Cham. | Fagaceae | 8 |
| Quercus laurina | Bonpl. | Fagaceae | 8 |
| Quercus magnoliifolia | Née | Fagaceae | 8 |
| Quercus mohriana | Buckley ex Rydb. | Fagaceae | 8 |
| Quercus muehlenbergii | Engelm. | Fagaceae | 8 |
| Quercus oblongifolia | Torr. | Fagaceae | 8 |
| Quercus obtusata | Bonpl. | Fagaceae | 8 |
| Quercus oleoides | Schltdl. & Cham. | Fagaceae | 8 |
| Quercus polymorpha | Schltdl. & Cham. | Fagaceae | 8 |
| Quercus potosina | Trel. | Fagaceae | 8 |
| Quercus pungens | Liebm. | Fagaceae | 8 |
| Quercus resinosa | Liebm. | Fagaceae | 8 |
| Quercus rugosa | Née | Fagaceae | 8 |
| Quercus rysophylla | Weath. | Fagaceae | 8 |
| Quercus saltillensis | Trel. | Fagaceae | 8 |
| Quercus sapotifolia | Liebm. | Fagaceae | 8 |
| Quercus sebifera | Trel. | Fagaceae | 8 |
| Quercus sideroxyla | Bonpl. | Fagaceae | 8 |
| Quercus sinuata | Walter | Fagaceae | 8 |
| Quercus skinneri | Benth. | Fagaceae | 8 |
| Quercus striatula | Trel. | Fagaceae | 8 |
| Quercus toumeyi | Sarg. | Fagaceae | 8 |
| Quercus turbinella | Greene | Fagaceae | 8 |
| Quercus vaseyana | Buckley | Fagaceae | 8 |
| Quincula lobata | (Torr.) Raf. | Solanaceae | 8 |
| Rafinesquia neomexicana | A.Gray | Asteraceae | 8 |
| Randia aculeata | L. | Rubiaceae | 8 |
| Randia capitata | DC. | Rubiaceae | 8 |
| Randia echinocarpa | Moc. & Sessé ex DC. | Rubiaceae | 8 |
| Randia obcordata | S.Watson | Rubiaceae | 8 |
| Randia thurberi | S.Watson | Rubiaceae | 8 |
| Ranunculus macranthus | Scheele | Ranunculaceae | 8 |
| Ranunculus petiolaris | Kunth | Ranunculaceae | 8 |
| Ranunculus sierrae-orientalis | (L.D.Benson) G.L.Nesom | Ranunculaceae | 8 |
| Rapicactus beguinii | (N.P.Taylor) Lüthy | Cactaceae | 8 |
| Ratibida columnifera | (Nutt.) Wooton & Standl. | Asteraceae | 8 |
| Ratibida peduncularis | Barnhart | Asteraceae | 8 |
| Ratibida tagetes | (E.James) Barnhart | Asteraceae | 8 |
| Rauvolfia tetraphylla | L. | Apocynaceae | 8 |
| Rayjacksonia phyllocephala | (DC.) R.L.Hartm. & M.A.Lane | Asteraceae | 8 |
| Renealmia mexicana | Klotzsch ex Petersen | Zingiberaceae | 8 |
| Rhamnus crocea | Nutt. | Rhamnaceae | 8 |
| Rhinotropis lindheimeri | (A.Gray) J.R.Abbott | Polygalaceae | 8 |
| Rhipsalis baccifera | (Sol. ex J.S.Muell.) Stearn | Cactaceae | 8 |
| Rhizophora mangle | L. | Rhizophoraceae | 8 |
| Rhus aromatica | Aiton | Anacardiaceae | 8 |
| Rhus copallinum | L. | Anacardiaceae | 8 |
| Rhus glabra | L. | Anacardiaceae | 8 |
| Rhus microphylla | Engelm. | Anacardiaceae | 8 |
| Rhus ovata | S.Watson | Anacardiaceae | 8 |
| Rhus schiedeana | Schltdl. | Anacardiaceae | 8 |
| Rhus standleyi | F.A.Barkley | Anacardiaceae | 8 |
| Rhus terebinthifolia | Schltdl. & Cham. | Anacardiaceae | 8 |
| Rhus virens | Lindh. ex A.Gray | Anacardiaceae | 8 |
| Rhynchoglossum azureum | (Schltdl.) B.L.Burtt | Gesneriaceae | 8 |
| Rhynchosia americana | (Mill.) Metz | Fabaceae | 8 |
| Rhynchosia difformis | (Elliott) DC. | Fabaceae | 8 |
| Rhynchosia edulis | Griseb. | Fabaceae | 8 |
| Rhynchosia longeracemosa | M.Martens & Galeotti | Fabaceae | 8 |
| Rhynchosia minima | (L.) DC. | Fabaceae | 8 |
| Rhynchosia precatoria | (Humb. & Bonpl. ex Willd.) DC. | Fabaceae | 8 |
| Rhynchosia prostrata | Brandegee | Fabaceae | 8 |
| Rhynchosia senna | Gillies ex Hook. & Arn. | Fabaceae | 8 |
| Rhynchosida physocalyx | (A.Gray) Fryxell | Malvaceae | 8 |
| Rhynchospora colorata | (L.) H.Pfeiff. | Cyperaceae | 8 |
| Rhynchospora nervosa | (Vahl) Boeckeler | Cyperaceae | 8 |
| Rhynchospora nivea | Boeckeler | Cyperaceae | 8 |
| Ribes ciliatum | Humb. & Bonpl. ex Schult. | Grossulariaceae | 8 |
| Ribes leptanthum | A.Gray | Grossulariaceae | 8 |
| Ribes mescalerium | Coville | Grossulariaceae | 8 |
| Richardia scabra | L. | Rubiaceae | 8 |
| Richardia tricocca | (Torr. & A.Gray) Standl. | Rubiaceae | 8 |
| Rivina humilis | L. | Petiveriaceae | 8 |
| Robinia neomexicana | A.Gray | Fabaceae | 8 |
| Roldana angulifolia | (DC.) H.Rob. & Brettell | Asteraceae | 8 |
| Roldana barba-johannis | (DC.) H.Rob. & Brettell | Asteraceae | 8 |
| Roldana candicans | (Née) Villaseñor, S.Valencia & Coombes | Asteraceae | 8 |
| Roldana hartwegii | (Benth.) H.Rob. & Brettell | Asteraceae | 8 |
| Roldana heracleifolia | (Hemsl.) H.Rob. & Brettell | Asteraceae | 8 |
| Roldana lobata | La Llave | Asteraceae | 8 |
| Roldana petasitis | (Sims) H.Rob. & Brettell | Asteraceae | 8 |
| Rorippa curvipes | Greene | Brassicaceae | 8 |
| Rorippa teres | (Michx.) Stuckey | Brassicaceae | 8 |
| Rosa carolina | L. | Rosaceae | 8 |
| Rosa woodsii | Lindl. | Rosaceae | 8 |
| Rotala ramosior | (L.) Koehne | Lythraceae | 8 |
| Rubus adenotrichos | Schltdl. | Rosaceae | 8 |
| Rubus coriifolius | Liebm. | Rosaceae | 8 |
| Rubus deliciosus | Torr. | Rosaceae | 8 |
| Rubus flagellaris | Willd. | Rosaceae | 8 |
| Rubus idaeus | L. | Rosaceae | 8 |
| Rubus leucodermis | (Douglas ex Hook.) Douglas ex Torr. & A.Gray | Rosaceae | 8 |
| Rubus parviflorus | Nutt. | Rosaceae | 8 |
| Rubus trivialis | Michx. | Rosaceae | 8 |
| Ruehssia mexicana | (Decne.) L.O.Alvarado | Apocynaceae | 8 |
| Ruellia blechum | L. | Acanthaceae | 8 |
| Ruellia ciliatiflora | Hook. | Acanthaceae | 8 |
| Ruellia corzoi | Tharp & F.A.Barkley | Acanthaceae | 8 |
| Ruellia erythropus | (Nees) Lindau | Acanthaceae | 8 |
| Ruellia inundata | Kunth | Acanthaceae | 8 |
| Ruellia lactea | Cav. | Acanthaceae | 8 |
| Ruellia longepetiolata | (Oerst.) Hemsl. | Acanthaceae | 8 |
| Ruellia metziae | Tharp | Acanthaceae | 8 |
| Ruellia parryi | A.Gray | Acanthaceae | 8 |
| Ruellia pedunculata | Torr. ex A.Gray | Acanthaceae | 8 |
| Ruellia simplex | C.Wright | Acanthaceae | 8 |
| Ruellia tuberosa | L. | Acanthaceae | 8 |
| Rumex altissimus | Alph.Wood | Polygonaceae | 8 |
| Rumex hymenosepalus | Torr. | Polygonaceae | 8 |
| Rumex salicifolius | Weinm. | Polygonaceae | 8 |
| Rumex triangulivalvis | (Danser) Rech.f. | Polygonaceae | 8 |
| Rumex verticillatus | L. | Polygonaceae | 8 |
| Rumfordia floribunda | DC. | Asteraceae | 8 |
| Ruppia maritima | L. | Ruppiaceae | 8 |
| Russelia equisetiformis | Schltdl. & Cham. | Plantaginaceae | 8 |
| Russelia sarmentosa | Jacq. | Plantaginaceae | 8 |
| Russelia verticillata | Kunth | Plantaginaceae | 8 |
| Sabal mexicana | Mart. | Arecaceae | 8 |
| Sabatia stellaris | Pursh | Gentianaceae | 8 |
| Sabazia multiradiata | (Seaton) Longpre | Asteraceae | 8 |
| Sabdariffa furcellata | (Desr.) M.M.Hanes & R.L.Barrett | Malvaceae | 8 |
| Sacoila lanceolata | (Aubl.) Garay | Orchidaceae | 8 |
| Sagina saginoides | (L.) H.Karst. | Caryophyllaceae | 8 |
| Sagittaria latifolia | Willd. | Alismataceae | 8 |
| Sagittaria longiloba | Engelm. ex J.G.Sm. | Alismataceae | 8 |
| Sagittaria montevidensis | Cham. & Schltdl. | Alismataceae | 8 |
| Sagittaria platyphylla | (Engelm.) J.G.Sm. | Alismataceae | 8 |
| Salicornia bigelovii | Torr. | Chenopodiaceae | 8 |
| Salix bonplandiana | Kunth | Salicaceae | 8 |
| Salix caroliniana | Michx. | Salicaceae | 8 |
| Salix exigua | Nutt. | Salicaceae | 8 |
| Salix gooddingii | C.R.Ball | Salicaceae | 8 |
| Salix humboldtiana | Willd. | Salicaceae | 8 |
| Salix interior | Rowlee | Salicaceae | 8 |
| Salix lasiolepis | Benth. | Salicaceae | 8 |
| Salix nigra | Marshall | Salicaceae | 8 |
| Salix scouleriana | Barratt | Salicaceae | 8 |
| Salix taxifolia | Kunth | Salicaceae | 8 |
| Salpianthus purpurascens | (Cav. ex Lag.) Hook. & Arn. | Nyctaginaceae | 8 |
| Salvia arizonica | A.Gray | Lamiaceae | 8 |
| Salvia axillaris | Moc. & Sessé ex Benth. | Lamiaceae | 8 |
| Salvia ballotiflora | Benth. | Lamiaceae | 8 |
| Salvia carnea | Kunth | Lamiaceae | 8 |
| Salvia caudata | Epling | Lamiaceae | 8 |
| Salvia chamaedryoides | Cav. | Lamiaceae | 8 |
| Salvia cinnabarina | M.Martens & Galeotti | Lamiaceae | 8 |
| Salvia circinnata | Cav. | Lamiaceae | 8 |
| Salvia coahuilensis | Fernald | Lamiaceae | 8 |
| Salvia coccinea | Buc'hoz ex Etl. | Lamiaceae | 8 |
| Salvia connivens | Epling | Lamiaceae | 8 |
| Salvia coulteri | Fernald | Lamiaceae | 8 |
| Salvia crucis | Epling | Lamiaceae | 8 |
| Salvia curviflora | Benth. | Lamiaceae | 8 |
| Salvia elegans | Vahl | Lamiaceae | 8 |
| Salvia farinacea | Benth. | Lamiaceae | 8 |
| Salvia greggii | A.Gray | Lamiaceae | 8 |
| Salvia helianthemifolia | Benth. | Lamiaceae | 8 |
| Salvia heterotricha | Fernald | Lamiaceae | 8 |
| Salvia hirsuta | Jacq. | Lamiaceae | 8 |
| Salvia hispanica | L. | Lamiaceae | 8 |
| Salvia involucrata | Cav. | Lamiaceae | 8 |
| Salvia iodantha | Fernald | Lamiaceae | 8 |
| Salvia laevis | Benth. | Lamiaceae | 8 |
| Salvia lasiantha | Benth. | Lamiaceae | 8 |
| Salvia lasiocephala | Hook. & Arn. | Lamiaceae | 8 |
| Salvia lavanduloides | Kunth | Lamiaceae | 8 |
| Salvia leptostachys | Benth. | Lamiaceae | 8 |
| Salvia leucantha | Cav. | Lamiaceae | 8 |
| Salvia longistyla | Benth. | Lamiaceae | 8 |
| Salvia lycioides | A.Gray | Lamiaceae | 8 |
| Salvia melissodora | Lag. | Lamiaceae | 8 |
| Salvia mexicana | L. | Lamiaceae | 8 |
| Salvia microphylla | Kunth | Lamiaceae | 8 |
| Salvia misella | Kunth | Lamiaceae | 8 |
| Salvia mocinoi | Benth. | Lamiaceae | 8 |
| Salvia nana | Kunth | Lamiaceae | 8 |
| Salvia occidentalis | Sw. | Lamiaceae | 8 |
| Salvia patens | Cav. | Lamiaceae | 8 |
| Salvia pinguifolia | (Fernald) Wooton & Standl. | Lamiaceae | 8 |
| Salvia polystachia | Cav. | Lamiaceae | 8 |
| Salvia prunelloides | Kunth | Lamiaceae | 8 |
| Salvia purpurea | Cav. | Lamiaceae | 8 |
| Salvia reflexa | Hornem. | Lamiaceae | 8 |
| Salvia regla | Cav. | Lamiaceae | 8 |
| Salvia reptans | Jacq. | Lamiaceae | 8 |
| Salvia roemeriana | Scheele | Lamiaceae | 8 |
| Salvia sessei | Benth. | Lamiaceae | 8 |
| Salvia subincisa | Benth. | Lamiaceae | 8 |
| Salvia texana | (Scheele) Torr. | Lamiaceae | 8 |
| Salvia tiliifolia | Vahl | Lamiaceae | 8 |
| Salvia tubifera | Cav. | Lamiaceae | 8 |
| Salvia urolepis | Fernald | Lamiaceae | 8 |
| Salvia xalapensis | Benth. | Lamiaceae | 8 |
| Salvia zamoranensis | Zamudio & Bedolla | Lamiaceae | 8 |
| Salvinia minima | Baker | Salviniaceae | 8 |
| Sambucus canadensis | L. | Viburnaceae | 8 |
| Sambucus peruviana | Kunth | Viburnaceae | 8 |
| Samolus ebracteatus | Kunth | Primulaceae | 8 |
| Samolus parviflorus | Raf. | Primulaceae | 8 |
| Sanicula liberta | Cham. & Schltdl. | Apiaceae | 8 |
| Sanvitalia ocymoides | DC. | Asteraceae | 8 |
| Sanvitalia procumbens | Lam. | Asteraceae | 8 |
| Sapindus drummondii | Hook. & Arn. | Sapindaceae | 8 |
| Sapindus saponaria | L. | Sapindaceae | 8 |
| Sarcoglottis sceptrodes | (Rchb.f.) Schltr. | Orchidaceae | 8 |
| Sarcoglottis schaffneri | (Rchb.f.) Ames | Orchidaceae | 8 |
| Sarcomphalus amole | (Sessé & Moc.) Hauenschild | Rhamnaceae | 8 |
| Sartwellia flaveriae | A.Gray | Asteraceae | 8 |
| Saurauia scabrida | Hemsl. | Actinidiaceae | 8 |
| Saurauia yasicae | Loes. | Actinidiaceae | 8 |
| Saururus cernuus | L. | Saururaceae | 8 |
| Scaevola plumieri | (L.) Vahl | Goodeniaceae | 8 |
| Schaefferia cuneifolia | A.Gray | Celastraceae | 8 |
| Schaefferia frutescens | Jacq. | Celastraceae | 8 |
| Schiedeella affinis | (C.Schweinf.) Salazar | Orchidaceae | 8 |
| Schisandra glabra | (Brickell) Rehder | Schisandraceae | 8 |
| Schistocarpha eupatorioides | (Fenzl) Kuntze | Asteraceae | 8 |
| Schistophragma intermedium | (A.Gray) Pennell | Plantaginaceae | 8 |
| Schizachyrium microstachyum | (Desv.) Roseng., B.R.Arrill. & Izag. | Poaceae | 8 |
| Schizachyrium sanguineum | (Retz.) Alston | Poaceae | 8 |
| Schizachyrium scoparium | (Michx.) Nash | Poaceae | 8 |
| Schizocarpum palmeri | Cogn. & Rose | Cucurbitaceae | 8 |
| Schizocarpum parviflorum | B.L.Rob. & Greenm. | Cucurbitaceae | 8 |
| Schkuhria pinnata | (Lam.) Kuntze ex Thell. | Asteraceae | 8 |
| Schoenocaulon caricifolium | (Schltdl.) A.Gray | Melanthiaceae | 8 |
| Schoenocaulon ghiesbreghtii | Greenm. | Melanthiaceae | 8 |
| Schoenocaulon texanum | Scheele | Melanthiaceae | 8 |
| Schoenoplectus americanus | (Pers.) Volkart | Cyperaceae | 8 |
| Schoenoplectus californicus | (C.A.Mey.) Soják | Cyperaceae | 8 |
| Schoenoplectus pungens | (Vahl) Palla | Cyperaceae | 8 |
| Schoenoplectus tabernaemontani | (C.C.Gmel.) Palla | Cyperaceae | 8 |
| Schoenus nigricans | L. | Cyperaceae | 8 |
| Scirpus cyperinus | (L.) Kunth | Cyperaceae | 8 |
| Scirpus pendulus | Muhl. | Cyperaceae | 8 |
| Scleria ciliata | Michx. | Cyperaceae | 8 |
| Scleria muehlenbergii | Steud. | Cyperaceae | 8 |
| Scleria oligantha | Michx. | Cyperaceae | 8 |
| Scleria pauciflora | Muhl. ex Willd. | Cyperaceae | 8 |
| Scleria verticillata | Muhl. ex Willd. | Cyperaceae | 8 |
| Sclerocactus brevihamatus | (Engelm.) D.R.Hunt | Cactaceae | 8 |
| Sclerocactus intertextus | (Engelm.) N.P.Taylor | Cactaceae | 8 |
| Sclerocactus mariposensis | (Hester) N.P.Taylor | Cactaceae | 8 |
| Sclerocactus papyracanthus | (Engelm.) N.P.Taylor | Cactaceae | 8 |
| Sclerocactus scheeri | (Salm-Dyck) N.P.Taylor | Cactaceae | 8 |
| Sclerocactus unguispinus | (Engelm.) N.P.Taylor | Cactaceae | 8 |
| Sclerocactus warnockii | (L.D.Benson) N.P.Taylor | Cactaceae | 8 |
| Sclerocarpus divaricatus | (Benth.) Benth. & Hook.f. ex Hemsl. | Asteraceae | 8 |
| Sclerocarpus uniserialis | (Hook.) Benth. & Hook.f. ex Hemsl. | Asteraceae | 8 |
| Scleropogon brevifolius | Phil. | Poaceae | 8 |
| Scoparia dulcis | L. | Plantaginaceae | 8 |
| Scutellaria drummondii | Benth. | Lamiaceae | 8 |
| Scutellaria dumetorum | Schltdl. | Lamiaceae | 8 |
| Scutellaria mexicana | (Torr.) A.J.Paton | Lamiaceae | 8 |
| Scutellaria ovata | Hill | Lamiaceae | 8 |
| Scutellaria potosina | Brandegee | Lamiaceae | 8 |
| Scutellaria racemosa | Pers. | Lamiaceae | 8 |
| Scutellaria seleriana | Loes. | Lamiaceae | 8 |
| Sedum calcicola | B.L.Rob. & Greenm. | Crassulaceae | 8 |
| Sedum cockerellii | Britton | Crassulaceae | 8 |
| Sedum dendroideum | Moc. & Sessé ex DC. | Crassulaceae | 8 |
| Sedum ebracteatum | Moc. & Sessé ex DC. | Crassulaceae | 8 |
| Sedum goldmanii | (Rose) Moran | Crassulaceae | 8 |
| Sedum greggii | Hemsl. | Crassulaceae | 8 |
| Sedum jaliscanum | S.Watson | Crassulaceae | 8 |
| Sedum jurgensenii | (Hemsl.) Moran | Crassulaceae | 8 |
| Sedum moranense | Kunth | Crassulaceae | 8 |
| Sedum oxypetalum | Kunth | Crassulaceae | 8 |
| Sedum palmeri | S.Watson | Crassulaceae | 8 |
| Sedum potosinum | Rose | Crassulaceae | 8 |
| Sedum praealtum | A.DC. | Crassulaceae | 8 |
| Sedum stelliforme | S.Watson | Crassulaceae | 8 |
| Sedum vinicolor | S.Watson | Crassulaceae | 8 |
| Sedum wrightii | A.Gray | Crassulaceae | 8 |
| Selaginella apoda | Spring | Selaginellaceae | 8 |
| Selaginella arizonica | Maxon | Selaginellaceae | 8 |
| Selaginella eremophila | Maxon | Selaginellaceae | 8 |
| Selaginella lepidophylla | (Hook. & Grev.) Spring | Selaginellaceae | 8 |
| Selaginella mutica | D.C.Eaton | Selaginellaceae | 8 |
| Selaginella pallescens | (C.Presl) Spring | Selaginellaceae | 8 |
| Selaginella peruviana | Hieron. | Selaginellaceae | 8 |
| Selaginella pilifera | A.Br. | Selaginellaceae | 8 |
| Selaginella rupincola | Underw. | Selaginellaceae | 8 |
| Selaginella sellowii | Hieron. | Selaginellaceae | 8 |
| Selaginella underwoodii | Hieron. | Selaginellaceae | 8 |
| Selaginella wrightii | Hieron. | Selaginellaceae | 8 |
| Selenicereus grandiflorus | (L.) Britton & Rose | Cactaceae | 8 |
| Selenicereus ocamponis | (Salm-Dyck) D.R.Hunt | Cactaceae | 8 |
| Selenicereus pteranthus | (Link ex A.Dietr.) Britton & Rose | Cactaceae | 8 |
| Selenicereus spinulosus | (DC.) Britton & Rose | Cactaceae | 8 |
| Selenicereus undatus | (Haw.) D.R.Hunt | Cactaceae | 8 |
| Semialarium mexicanum | (Miers) Mennega | Celastraceae | 8 |
| Senecio ampullaceus | Hook. | Asteraceae | 8 |
| Senecio andrieuxii | DC. | Asteraceae | 8 |
| Senecio callosus | Sch.Bip. | Asteraceae | 8 |
| Senecio cinerarioides | Kunth | Asteraceae | 8 |
| Senecio flaccidus | Less. | Asteraceae | 8 |
| Senecio lemmonii | A.Gray | Asteraceae | 8 |
| Senecio praecox | DC. | Asteraceae | 8 |
| Senecio sessilifolius | Hemsl. | Asteraceae | 8 |
| Senecio wootonii | Greene | Asteraceae | 8 |
| Senegalia berlandieri | (Benth.) Britton & Rose | Fabaceae | 8 |
| Senegalia greggii | (A.Gray) Britton & Rose | Fabaceae | 8 |
| Senegalia roemeriana | (Scheele) Britton & Rose | Fabaceae | 8 |
| Senegalia wrightii | (Benth.) Britton & Rose | Fabaceae | 8 |
| Senna atomaria | (L.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna bauhinioides | (A.Gray) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna covesii | (A.Gray) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna crotalarioides | (Kunth) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna hirsuta | (L.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna lindheimeriana | (Scheele) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna multiglandulosa | (Jacq.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna multijuga | (Rich.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna obtusifolia | (L.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna occidentalis | (L.) Link | Fabaceae | 8 |
| Senna pallida | (Vahl) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna pendula | (Humb. & Bonpl. ex Willd.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna pilosior | (B.L.Rob.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna polyantha | (Collad.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna pumilio | (A.Gray) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna racemosa | (Mill.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna roemeriana | (Scheele) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna septemtrionalis | (Viv.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna uniflora | (Mill.) H.S.Irwin & Barneby | Fabaceae | 8 |
| Senna wislizeni | (A.Gray) H.S.Irwin & Barneby | Fabaceae | 8 |
| Serjania brachycarpa | A.Gray ex Radlk. | Sapindaceae | 8 |
| Serjania mexicana | Willd. | Sapindaceae | 8 |
| Serjania racemosa | Schum. | Sapindaceae | 8 |
| Serjania triquetra | Radlk. | Sapindaceae | 8 |
| Sesbania drummondii | (Rydb.) Cory | Fabaceae | 8 |
| Sesbania herbacea | (Mill.) McVaugh | Fabaceae | 8 |
| Sesuvium maritimum | (Walter) Britton, Sterns & Poggenb. | Aizoaceae | 8 |
| Sesuvium portulacastrum | (L.) L. | Aizoaceae | 8 |
| Setaria grisebachii | E.Fourn. | Poaceae | 8 |
| Setaria leucopila | (Scribn. & Merr.) K.Schum. | Poaceae | 8 |
| Setaria liebmannii | E.Fourn. | Poaceae | 8 |
| Setaria magna | Griseb. | Poaceae | 8 |
| Setaria parviflora | (Poir.) Kerguélen | Poaceae | 8 |
| Setaria reverchonii | (Vasey) Pilg. | Poaceae | 8 |
| Setaria scheelei | (Steud.) Hitchc. | Poaceae | 8 |
| Seymeria decurva | Benth. | Orobanchaceae | 8 |
| Shinnersia rivularis | (A.Gray) R.M.King & H.Rob. | Asteraceae | 8 |
| Sibthorpia repens | (Mutis ex L.) Kuntze | Plantaginaceae | 8 |
| Sicyos edulis | Jacq. | Cucurbitaceae | 8 |
| Sicyos laciniatus | L. | Cucurbitaceae | 8 |
| Sicyos microphyllus | Kunth | Cucurbitaceae | 8 |
| Sida acuta | Burm.f. | Malvaceae | 8 |
| Sida ciliaris | L. | Malvaceae | 8 |
| Sida cordifolia | L. | Malvaceae | 8 |
| Sida elliottii | Torr. & A.Gray | Malvaceae | 8 |
| Sida haenkeana | C.Presl | Malvaceae | 8 |
| Sida lindheimeri | Engelm. & Gray | Malvaceae | 8 |
| Sida linearis | Cav. | Malvaceae | 8 |
| Sida linifolia | Cav. | Malvaceae | 8 |
| Sida spinosa | L. | Malvaceae | 8 |
| Sida ulmifolia | Mill. | Malvaceae | 8 |
| Sidalcea neomexicana | A.Gray | Malvaceae | 8 |
| Sidastrum tehuacanum | (Brandegee) Fryxell | Malvaceae | 8 |
| Sideroxylon capiri | (A.DC.) Pittier | Sapotaceae | 8 |
| Sideroxylon celastrinum | (Kunth) T.D.Penn. | Sapotaceae | 8 |
| Sideroxylon lanuginosum | Michx. | Sapotaceae | 8 |
| Sideroxylon persimile | (Hemsl.) T.D.Penn. | Sapotaceae | 8 |
| Sideroxylon salicifolium | (L.) Lam. | Sapotaceae | 8 |
| Sidneya tenuifolia | (A.Gray) E.E.Schill. & Panero | Asteraceae | 8 |
| Sigesbeckia jorullensis | Kunth | Asteraceae | 8 |
| Silene laciniata | Cav. | Caryophyllaceae | 8 |
| Silene scouleri | Hook. | Caryophyllaceae | 8 |
| Simmondsia chinensis | (Link) C.K.Schneid. | Simmondsiaceae | 8 |
| Simsia amplexicaulis | (Cav.) Pers. | Asteraceae | 8 |
| Simsia calva | A.Gray | Asteraceae | 8 |
| Simsia eurylepis | S.F.Blake | Asteraceae | 8 |
| Simsia foetida | (Cav.) S.F.Blake | Asteraceae | 8 |
| Simsia sanguinea | A.Gray | Asteraceae | 8 |
| Sinclairia angustissima | (A.Gray) B.L.Turner | Asteraceae | 8 |
| Siparuna thecaphora | (Poepp. & Endl.) A.DC. | Siparunaceae | 8 |
| Sisyrinchium angustissimum | (B.L.Rob. & Greenm.) Greenm. & C.H.Thomps. | Iridaceae | 8 |
| Sisyrinchium biforme | E.P.Bicknell | Iridaceae | 8 |
| Sisyrinchium demissum | Greene | Iridaceae | 8 |
| Sisyrinchium micranthum | Cav. | Iridaceae | 8 |
| Sisyrinchium minus | Engelm. & A.Gray | Iridaceae | 8 |
| Sisyrinchium scabrum | Schltdl. & Cham. | Iridaceae | 8 |
| Sisyrinchium tenuifolium | Humb. & Bonpl. ex Willd. | Iridaceae | 8 |
| Smallanthus maculatus | (Cav.) H.Rob. | Asteraceae | 8 |
| Smallanthus uvedalia | (L.) Mack. | Asteraceae | 8 |
| Smilax bona-nox | L. | Smilacaceae | 8 |
| Smilax domingensis | Willd. | Smilacaceae | 8 |
| Smilax glauca | Walter | Smilacaceae | 8 |
| Smilax moranensis | M.Martens & Galeotti | Smilacaceae | 8 |
| Smilax spinosa | Mill. | Smilacaceae | 8 |
| Smilax subpubescens | A.DC. | Smilacaceae | 8 |
| Smilax tamnoides | L. | Smilacaceae | 8 |
| Smilax tomentosa | Kunth | Smilacaceae | 8 |
| Solandra maxima | (Sessé & Moc.) P.S.Green | Solanaceae | 8 |
| Solanum acerifolium | Dunal | Solanaceae | 8 |
| Solanum aligerum | Schltdl. | Solanaceae | 8 |
| Solanum americanum | Mill. | Solanaceae | 8 |
| Solanum aphyodendron | S.Knapp | Solanaceae | 8 |
| Solanum appendiculatum | Dunal | Solanaceae | 8 |
| Solanum aturense | Dunal | Solanaceae | 8 |
| Solanum campechiense | L. | Solanaceae | 8 |
| Solanum candidum | Lindl. | Solanaceae | 8 |
| Solanum carolinense | L. | Solanaceae | 8 |
| Solanum chrysotrichum | Schltdl. | Solanaceae | 8 |
| Solanum citrullifolium | A.Braun | Solanaceae | 8 |
| Solanum davisense | Whalen | Solanaceae | 8 |
| Solanum deflexum | Greenm. | Solanaceae | 8 |
| Solanum demissum | Lindl. | Solanaceae | 8 |
| Solanum dimidiatum | Raf. | Solanaceae | 8 |
| Solanum donianum | Walp. | Solanaceae | 8 |
| Solanum douglasii | Dunal | Solanaceae | 8 |
| Solanum elaeagnifolium | Cav. | Solanaceae | 8 |
| Solanum erianthum | D.Don | Solanaceae | 8 |
| Solanum ferrugineum | Jacq. | Solanaceae | 8 |
| Solanum grayi | Rose | Solanaceae | 8 |
| Solanum hazenii | Britton | Solanaceae | 8 |
| Solanum heterodoxum | Dunal | Solanaceae | 8 |
| Solanum hindsianum | Benth. | Solanaceae | 8 |
| Solanum hirtum | Vahl | Solanaceae | 8 |
| Solanum houstonii | Martyn | Solanaceae | 8 |
| Solanum jamaicense | Mill. | Solanaceae | 8 |
| Solanum jamesii | Torr. | Solanaceae | 8 |
| Solanum lanceolatum | Cav. | Solanaceae | 8 |
| Solanum mitlense | Dunal | Solanaceae | 8 |
| Solanum nigrescens | M.Martens & Galeotti | Solanaceae | 8 |
| Solanum pubigerum | Dunal | Solanaceae | 8 |
| Solanum rostratum | Dunal | Solanaceae | 8 |
| Solanum seaforthianum | Andrews | Solanaceae | 8 |
| Solanum stoloniferum | Schltdl. | Solanaceae | 8 |
| Solanum subinerme | Jacq. | Solanaceae | 8 |
| Solanum torvum | Sw. | Solanaceae | 8 |
| Solanum triquetrum | Cav. | Solanaceae | 8 |
| Solanum umbellatum | Mill. | Solanaceae | 8 |
| Solanum volubile | Sw. | Solanaceae | 8 |
| Solanum wendlandii | Hook.f. | Solanaceae | 8 |
| Solidago altissima | L. | Asteraceae | 8 |
| Solidago gigantea | Aiton | Asteraceae | 8 |
| Solidago juliae | G.L.Nesom | Asteraceae | 8 |
| Solidago mexicana | L. | Asteraceae | 8 |
| Solidago missouriensis | Nutt. | Asteraceae | 8 |
| Solidago petiolaris | Aiton | Asteraceae | 8 |
| Solidago simplex | Kunth | Asteraceae | 8 |
| Solidago velutina | DC. | Asteraceae | 8 |
| Solidago wrightii | A.Gray | Asteraceae | 8 |
| Sophora nuttalliana | B.L.Turner | Fabaceae | 8 |
| Sophora tomentosa | L. | Fabaceae | 8 |
| Sorghastrum nutans | (L.) Nash | Poaceae | 8 |
| Sotoa confusa | (Garay) Salazar | Orchidaceae | 8 |
| Spananthe paniculata | Jacq. | Apiaceae | 8 |
| Sparganium americanum | Nutt. | Typhaceae | 8 |
| Specklinia tribuloides | (Sw.) Pridgeon & M.W.Chase | Orchidaceae | 8 |
| Spermacoce confusa | Rendle | Rubiaceae | 8 |
| Spermacoce prostrata | Aubl. | Rubiaceae | 8 |
| Spermacoce remota | Lam. | Rubiaceae | 8 |
| Spermacoce verticillata | L. | Rubiaceae | 8 |
| Spermolepis inermis | (Nutt. ex DC.) Mathias & Constance | Apiaceae | 8 |
| Spermolepis lateriflora | G.L.Nesom | Apiaceae | 8 |
| Sphaeralcea coccinea | (Nutt.) Rydb. | Malvaceae | 8 |
| Sphaeralcea digitata | (Greene) Rydb. | Malvaceae | 8 |
| Sphaeralcea emoryi | Torr. ex A.Gray | Malvaceae | 8 |
| Sphaeralcea fendleri | A.Gray | Malvaceae | 8 |
| Sphaeralcea fulva | Greene | Malvaceae | 8 |
| Sphaeralcea hastulata | A.Gray | Malvaceae | 8 |
| Sphaeralcea incana | Torr. ex A.Gray | Malvaceae | 8 |
| Sphaeralcea laxa | Wooton & Standl. | Malvaceae | 8 |
| Sphaeralcea leptophylla | (A.Gray) Rydb. | Malvaceae | 8 |
| Sphaeralcea pedatifida | (A.Gray) A.Gray | Malvaceae | 8 |
| Sphaeralcea polychroma | La Duke | Malvaceae | 8 |
| Sphenopholis obtusata | (Michx.) Scribn. | Poaceae | 8 |
| Spigelia anthelmia | L. | Loganiaceae | 8 |
| Spigelia hedyotidea | A.DC. | Loganiaceae | 8 |
| Spigelia humboldtiana | Cham. & Schltdl. | Loganiaceae | 8 |
| Spigelia scabrella | Benth. | Loganiaceae | 8 |
| Spigelia splendens | Hook. | Loganiaceae | 8 |
| Spigelia texana | (Torr. & A.Gray) A.DC. | Loganiaceae | 8 |
| Spiranthes vernalis | Engelm. & A.Gray | Orchidaceae | 8 |
| Spirodela polyrhiza | (L.) Schleid. | Araceae | 8 |
| Spondias mombin | L. | Anacardiaceae | 8 |
| Spondias purpurea | L. | Anacardiaceae | 8 |
| Sporobolus airoides | (Torr.) Torr. | Poaceae | 8 |
| Sporobolus alterniflorus | (Loisel.) P.M.Peterson & Saarela | Poaceae | 8 |
| Sporobolus arenicola | P.M.Peterson | Poaceae | 8 |
| Sporobolus compositus | (Poir.) Merr. | Poaceae | 8 |
| Sporobolus contractus | Hitchc. | Poaceae | 8 |
| Sporobolus cryptandrus | (Torr.) A.Gray | Poaceae | 8 |
| Sporobolus cynosuroides | (L.) P.M.Peterson & Saarela | Poaceae | 8 |
| Sporobolus flexuosus | (Vasey) Rydb. | Poaceae | 8 |
| Sporobolus giganteus | Nash | Poaceae | 8 |
| Sporobolus indicus | (L.) R.Br. | Poaceae | 8 |
| Sporobolus nealleyi | Vasey | Poaceae | 8 |
| Sporobolus pumilus | (Roth) P.M.Peterson & Saarela | Poaceae | 8 |
| Sporobolus pyramidatus | (Lam.) Hitchc. | Poaceae | 8 |
| Sporobolus wrightii | Scribn. | Poaceae | 8 |
| Stachys agraria | Schltdl. & Cham. | Lamiaceae | 8 |
| Stachys bigelovii | A.Gray | Lamiaceae | 8 |
| Stachys coccinea | Ortega | Lamiaceae | 8 |
| Stachys drummondii | Benth. | Lamiaceae | 8 |
| Stachytarpheta acuminata | DC. ex Schauer | Verbenaceae | 8 |
| Stachytarpheta frantzii | Pol. | Verbenaceae | 8 |
| Stachytarpheta indica | (L.) Vahl | Verbenaceae | 8 |
| Stachytarpheta jamaicensis | (L.) Vahl | Verbenaceae | 8 |
| Stachytarpheta mutabilis | (Jacq.) Vahl | Verbenaceae | 8 |
| Stanleya pinnata | (Pursh) Britton | Brassicaceae | 8 |
| Stapfochloa ciliata | (Sw.) P.M.Peterson | Poaceae | 8 |
| Steinchisma hians | (Elliott) Nash | Poaceae | 8 |
| Stelis emarginata | (Lindl.) Soto Arenas & Solano | Orchidaceae | 8 |
| Stellaria cuspidata | D.F.K.Schltdl. | Caryophyllaceae | 8 |
| Stemodia durantifolia | (L.) Sw. | Plantaginaceae | 8 |
| Stemodia lanata | Ruiz & Pav. ex Benth. | Plantaginaceae | 8 |
| Stemodia macrantha | B.L.Rob. | Plantaginaceae | 8 |
| Stenandrium barbatum | Torr. & A.Gray | Acanthaceae | 8 |
| Stenandrium dulce | (Cav.) Nees | Acanthaceae | 8 |
| Stenandrium verticillatum | Brandegee | Acanthaceae | 8 |
| Stenaria nigricans | (Lam.) Terrell | Rubiaceae | 8 |
| Stenocactus coptonogonus | A.Berger | Cactaceae | 8 |
| Stenocactus crispatus | (DC.) A.Berger | Cactaceae | 8 |
| Stenocactus phyllacanthus | (Mart) A.Berger | Cactaceae | 8 |
| Stenocereus griseus | (Haw.) Buxb. | Cactaceae | 8 |
| Stenocereus kerberi | (K.Schum.) A.C.Gibson & K.E.Horak | Cactaceae | 8 |
| Stenocereus pruinosus | (Otto ex Pfeiff.) Buxb. | Cactaceae | 8 |
| Stenocereus queretaroensis | (F.A.C.Weber) Buxb. | Cactaceae | 8 |
| Stenocereus thurberi | (Engelm.) Buxb. | Cactaceae | 8 |
| Stenostephanus haematodes | (Schltdl.) T.F.Daniel | Acanthaceae | 8 |
| Stephanomeria exigua | Nutt. | Asteraceae | 8 |
| Stephanomeria pauciflora | (Torr.) A.Nelson | Asteraceae | 8 |
| Stephanomeria thurberi | A.Gray | Asteraceae | 8 |
| Stevia elatior | Kunth | Asteraceae | 8 |
| Stevia lucida | Lag. | Asteraceae | 8 |
| Stevia ovata | Willd. | Asteraceae | 8 |
| Stevia plummerae | A.Gray | Asteraceae | 8 |
| Stevia salicifolia | Cav. | Asteraceae | 8 |
| Stevia serrata | Cav. | Asteraceae | 8 |
| Stevia subpubescens | Lag. | Asteraceae | 8 |
| Stevia tomentosa | Kunth | Asteraceae | 8 |
| Stevia triflora | DC. | Asteraceae | 8 |
| Stevia viscida | Kunth | Asteraceae | 8 |
| Sticherus fulvus | (Desv.) Ching | Gleicheniaceae | 8 |
| Stigmaphyllon dichotomum | (L.) Griseb. | Malpighiaceae | 8 |
| Stillingia texana | I.M.Johnst. | Euphorbiaceae | 8 |
| Stillingia treculiana | (Müll.Arg.) I.M.Johnst. | Euphorbiaceae | 8 |
| Streptanthus carinatus | Wright ex A.Gray | Brassicaceae | 8 |
| Streptanthus hyacinthoides | Hook. | Brassicaceae | 8 |
| Streptanthus platycarpus | A.Gray | Brassicaceae | 8 |
| Strombocarpa cinerascens | A.Gray | Fabaceae | 8 |
| Strombocarpa pubescens | (Benth.) A.Gray | Fabaceae | 8 |
| Strophostyles umbellata | (Muhl. ex Willd.) Britton | Fabaceae | 8 |
| Stuckenia pectinata | (L.) Börner | Potamogetonaceae | 8 |
| Stylocline micropoides | A.Gray | Asteraceae | 8 |
| Stylosanthes viscosa | (L.) Sw. | Fabaceae | 8 |
| Styrax argenteus | C.Presl | Styracaceae | 8 |
| Styrax glabrescens | Benth. | Styracaceae | 8 |
| Styrax platanifolius | Engelm. ex Torr. | Styracaceae | 8 |
| Suaeda linearis | (Elliott) Moq. | Chenopodiaceae | 8 |
| Suaeda nigra | (Raf.) J.F.Macbr. | Chenopodiaceae | 8 |
| Suaeda taxifolia | (Standl.) Standl. | Chenopodiaceae | 8 |
| Swietenia humilis | Zucc. | Meliaceae | 8 |
| Swietenia macrophylla | King | Meliaceae | 8 |
| Symphoricarpos longiflorus | A.Gray | Caprifoliaceae | 8 |
| Symphoricarpos orbiculatus | Moench | Caprifoliaceae | 8 |
| Symphoricarpos rotundifolius | A.Gray | Caprifoliaceae | 8 |
| Symphyotrichum bullatum | (Klatt) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum carnerosanum | (S.Watson) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum drummondii | (Lindl.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum ericoides | (L.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum falcatum | (Lindl.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum laeve | (L.) Á.Löve & D.Löve | Asteraceae | 8 |
| Symphyotrichum lanceolatum | (Willd.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum oblongifolium | (Nutt.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum praealtum | (Poir.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum trilineatum | (Sch.Bip. ex Klatt) G.L.Nesom | Asteraceae | 8 |
| Symplocos coccinea | Bonpl. | Symplocaceae | 8 |
| Syngonium angustatum | Schott | Araceae | 8 |
| Syngonium neglectum | Schott | Araceae | 8 |
| Syngonium podophyllum | Schott | Araceae | 8 |
| Synthlipsis greggii | A.Gray | Brassicaceae | 8 |
| Syringodium filiforme | Kütz. | Cymodoceaceae | 8 |
| Tabebuia rosea | (Bertol.) DC. | Bignoniaceae | 8 |
| Tabernaemontana alba | Mill. | Apocynaceae | 8 |
| Tabernaemontana amygdalifolia | Jacq. | Apocynaceae | 8 |
| Tabernaemontana donnell-smithii | Rose | Apocynaceae | 8 |
| Tabernaemontana glabra | (Benth.) A.O.Simões & M.E.Endress | Apocynaceae | 8 |
| Tabernaemontana litoralis | Kunth | Apocynaceae | 8 |
| Tabernaemontana tomentosa | (Greenm.) A.O.Simões & M.E.Endress | Apocynaceae | 8 |
| Tagetes epapposa | B.L.Turner | Asteraceae | 8 |
| Tagetes erecta | L. | Asteraceae | 8 |
| Tagetes filifolia | Lag. | Asteraceae | 8 |
| Tagetes foetidissima | hort. ex DC. | Asteraceae | 8 |
| Tagetes lemmonii | A.Gray | Asteraceae | 8 |
| Tagetes lucida | Cav. | Asteraceae | 8 |
| Tagetes lunulata | Ortega | Asteraceae | 8 |
| Tagetes micrantha | Cav. | Asteraceae | 8 |
| Tagetes moorei | H.Rob. | Asteraceae | 8 |
| Tagetes subulata | Cerv. | Asteraceae | 8 |
| Tagetes tenuifolia | Cav. | Asteraceae | 8 |
| Talinopsis frutescens | A.Gray | Anacampserotaceae | 8 |
| Talinum aurantiacum | Engelm. | Talinaceae | 8 |
| Talinum fruticosum | (L.) Juss. | Talinaceae | 8 |
| Talinum paniculatum | (Jacq.) Gaertn. | Talinaceae | 8 |
| Talinum polygaloides | Gillies ex Arn. | Talinaceae | 8 |
| Tamaulipa azurea | (DC.) R.M.King & H.Rob. | Asteraceae | 8 |
| Tara cacalaco | (Bonpl.) Molinari & Sánchez Och. | Fabaceae | 8 |
| Tarenaya aculeata | (L.) Soares Neto & Roalson | Cleomaceae | 8 |
| Taxodium distichum | (L.) Rich. | Cupressaceae | 8 |
| Taxus floridana | Nutt. ex Chapm. | Taxaceae | 8 |
| Tecoma stans | (L.) Juss. | Bignoniaceae | 8 |
| Tectaria heracleifolia | (Willd.) Underw. | Tectariaceae | 8 |
| Telanthophora grandifolia | (Less.) H.Rob. & Brettell | Asteraceae | 8 |
| Tephrosia lindheimeri | A.Gray | Fabaceae | 8 |
| Tephrosia potosina | Brandegee | Fabaceae | 8 |
| Tephrosia thurberi | (Rydb.) C.E.Wood | Fabaceae | 8 |
| Ternstroemia tepezapote | Schltdl. & Cham. | Pentaphylacaceae | 8 |
| Tetraclea coulteri | A.Gray | Lamiaceae | 8 |
| Tetragonotheca texana | A.Gray & Engelm. | Asteraceae | 8 |
| Tetramerium nervosum | Nees | Acanthaceae | 8 |
| Tetraneuris linearifolia | Greene | Asteraceae | 8 |
| Tetraneuris scaposa | (DC.) Greene | Asteraceae | 8 |
| Tetrapterys mexicana | Hook. & Arn. | Malpighiaceae | 8 |
| Tetrapterys schiedeana | Schltdl. & Cham. | Malpighiaceae | 8 |
| Teucrium canadense | L. | Lamiaceae | 8 |
| Teucrium coahuilanum | B.L.Turner | Lamiaceae | 8 |
| Teucrium depressum | Small | Lamiaceae | 8 |
| Teucrium vesicarium | Mill. | Lamiaceae | 8 |
| Thalassia testudinum | Banks & Sol. ex K.D.Koenig | Hydrocharitaceae | 8 |
| Thalia geniculata | L. | Marantaceae | 8 |
| Thalictrum fendleri | Engelm. ex A.Gray | Ranunculaceae | 8 |
| Thalictrum guatemalense | C.DC. & Rose | Ranunculaceae | 8 |
| Thelesperma burridgeanum | S.F.Blake | Asteraceae | 8 |
| Thelesperma filifolium | (Hook.) A.Gray | Asteraceae | 8 |
| Thelesperma longipes | A.Gray | Asteraceae | 8 |
| Thelesperma megapotamicum | (Spreng.) Kuntze | Asteraceae | 8 |
| Thelesperma simplicifolium | (A.Gray) A.Gray | Asteraceae | 8 |
| Thelocactus bicolor | (Galeotti ex Pfeiff.) Britton & Rose | Cactaceae | 8 |
| Thelocactus hexaedrophorus | (Lem.) Britton & Rose | Cactaceae | 8 |
| Thelocactus leucacanthus | (Zucc. ex Pfeiff.) Britton & Rose | Cactaceae | 8 |
| Thelocactus rinconensis | (Poselg.) Britton & Rose | Cactaceae | 8 |
| Thelocactus setispinus | (Engelm.) E.F.Anderson | Cactaceae | 8 |
| Thelypodium wrightii | A.Gray | Brassicaceae | 8 |
| Thevetia ahouai | A.DC. | Apocynaceae | 8 |
| Thompsonella minutiflora | (Rose) Britton & Rose | Crassulaceae | 8 |
| Thouinia acuminata | S.Watson | Sapindaceae | 8 |
| Thouinidium decandrum | (Bonpl.) Radlk. | Sapindaceae | 8 |
| Thymophylla acerosa | (DC.) Strother | Asteraceae | 8 |
| Thymophylla micropoides | (DC.) Strother | Asteraceae | 8 |
| Thymophylla pentachaeta | (DC.) Small | Asteraceae | 8 |
| Thymophylla setifolia | Lag. | Asteraceae | 8 |
| Thymophylla tenuiloba | Small | Asteraceae | 8 |
| Thymophylla tephroleuca | (S.F.Blake) Strother | Asteraceae | 8 |
| Tidestromia lanuginosa | (Nutt.) Standl. | Amaranthaceae | 8 |
| Tidestromia suffruticosa | (Torr.) Standl. | Amaranthaceae | 8 |
| Tigridia augusta | Drapiez | Iridaceae | 8 |
| Tigridia multiflora | (Baker) Ravenna | Iridaceae | 8 |
| Tigridia pavonia | (L.f.) Redouté | Iridaceae | 8 |
| Tilia americana | L. | Malvaceae | 8 |
| Tillandsia achyrostachys | É.Morren ex Baker | Bromeliaceae | 8 |
| Tillandsia atroviridipetala | Matuda | Bromeliaceae | 8 |
| Tillandsia baileyi | Rose ex Small | Bromeliaceae | 8 |
| Tillandsia balbisiana | Schult. & Schult.f. | Bromeliaceae | 8 |
| Tillandsia bartramii | Elliott | Bromeliaceae | 8 |
| Tillandsia bourgaei | Baker | Bromeliaceae | 8 |
| Tillandsia brachycaulos | Schltdl. | Bromeliaceae | 8 |
| Tillandsia caput-medusae | É.Morren | Bromeliaceae | 8 |
| Tillandsia deppeana | Steud. | Bromeliaceae | 8 |
| Tillandsia erubescens | Schltdl. | Bromeliaceae | 8 |
| Tillandsia fasciculata | Sw. | Bromeliaceae | 8 |
| Tillandsia guatemalensis | L.B.Sm. | Bromeliaceae | 8 |
| Tillandsia heterophylla | É.Morren | Bromeliaceae | 8 |
| Tillandsia ionantha | Planch. | Bromeliaceae | 8 |
| Tillandsia juncea | (Ruiz & Pav.) Poir. | Bromeliaceae | 8 |
| Tillandsia limbata | Schltdl. | Bromeliaceae | 8 |
| Tillandsia makoyana | Baker | Bromeliaceae | 8 |
| Tillandsia multicaulis | Steud. | Bromeliaceae | 8 |
| Tillandsia parryi | Baker | Bromeliaceae | 8 |
| Tillandsia punctulata | Schltdl. & Cham. | Bromeliaceae | 8 |
| Tillandsia recurvata | (L.) L. | Bromeliaceae | 8 |
| Tillandsia schiedeana | Steud. | Bromeliaceae | 8 |
| Tillandsia usneoides | (L.) L. | Bromeliaceae | 8 |
| Tillandsia variabilis | Schltdl. | Bromeliaceae | 8 |
| Tillandsia violacea | Baker | Bromeliaceae | 8 |
| Tinantia anomala | C.B.Clarke | Commelinaceae | 8 |
| Tinantia erecta | (Jacq.) Fenzl | Commelinaceae | 8 |
| Tinantia pringlei | (S.Watson) Rohweder | Commelinaceae | 8 |
| Tiquilia canescens | (DC.) A.T.Richardson | Ehretiaceae | 8 |
| Tiquilia gossypina | (Wooton & Standl.) A.T.Richardson | Ehretiaceae | 8 |
| Tiquilia greggii | (Torr. & A.Gray) A.T.Richardson | Ehretiaceae | 8 |
| Tiquilia hispidissima | (Torr. & A.Gray) A.T.Richardson | Ehretiaceae | 8 |
| Tithonia diversifolia | (Hemsl.) A.Gray | Asteraceae | 8 |
| Tithonia longiradiata | (Bertol.) S.F.Blake | Asteraceae | 8 |
| Tithonia rotundifolia | S.F.Blake | Asteraceae | 8 |
| Tithonia thurberi | A.Gray | Asteraceae | 8 |
| Tithonia tubaeformis | (Jacq.) Cass. | Asteraceae | 8 |
| Tomostima cuneifolia | (Nutt. ex Torr. & A.Gray) Al-Shehbaz, M.Koch & Jordon-Thaden | Brassicaceae | 8 |
| Tomostima platycarpa | (Torr. & A.Gray) Al-Shehbaz, M.Koch & Jordon-Thaden | Brassicaceae | 8 |
| Townsendia exscapa | (Richardson) Porter | Asteraceae | 8 |
| Toxicodendron diversilobum | (Torr. & A.Gray) Greene | Anacardiaceae | 8 |
| Toxicodendron radicans | (L.) Kuntze | Anacardiaceae | 8 |
| Toxicoscordion paniculatum | (Nutt.) Rydb. | Melanthiaceae | 8 |
| Trachypogon spicatus | (L.f.) Kuntze | Poaceae | 8 |
| Tradescantia brevifolia | Rose | Commelinaceae | 8 |
| Tradescantia commelinoides | Schult. & Schult.f. | Commelinaceae | 8 |
| Tradescantia crassifolia | Cav. | Commelinaceae | 8 |
| Tradescantia pallida | (Rose) D.R.Hunt | Commelinaceae | 8 |
| Tradescantia pinetorum | Greene | Commelinaceae | 8 |
| Tradescantia wrightii | Rose & Bush | Commelinaceae | 8 |
| Tradescantia zanonia | (L.) Sw. | Commelinaceae | 8 |
| Tragia amblyodonta | (Müll.Arg.) Pax & K.Hoffm. | Euphorbiaceae | 8 |
| Tragia brevispica | Engelm. & A.Gray | Euphorbiaceae | 8 |
| Tragia glanduligera | Pax & K.Hoffm. | Euphorbiaceae | 8 |
| Tragia nepetifolia | Cav. | Euphorbiaceae | 8 |
| Tragia ramosa | Torr. | Euphorbiaceae | 8 |
| Trema micranthum | (L.) Blume | Cannabaceae | 8 |
| Trianthema portulacastrum | L. | Aizoaceae | 8 |
| Trichilia havanensis | Jacq. | Meliaceae | 8 |
| Trichilia hirta | L. | Meliaceae | 8 |
| Trichilia trifolia | L. | Meliaceae | 8 |
| Trichocentrum ascendens | (Lindl.) M.W.Chase & N.H.Williams | Orchidaceae | 8 |
| Trichocentrum luridum | (Lindl.) M.W.Chase & N.H.Williams | Orchidaceae | 8 |
| Trichogalium aschenbornii | (S.Schauer) Kadereit & Schneew. | Rubiaceae | 8 |
| Trichospermum mexicanum | (DC.) Baill. | Malvaceae | 8 |
| Trichostema arizonicum | A.Gray | Lamiaceae | 8 |
| Trichostigma octandrum | (L.) H.Walter | Petiveriaceae | 8 |
| Tridax balbisioides | (Kunth) A.Gray | Asteraceae | 8 |
| Tridax coronopifolia | (Kunth) Hemsl. | Asteraceae | 8 |
| Tridax palmeri | A.Gray | Asteraceae | 8 |
| Tridax procumbens | L. | Asteraceae | 8 |
| Tridax rosea | Sch.Bip. | Asteraceae | 8 |
| Tridax trilobata | Hemsl. | Asteraceae | 8 |
| Tridens albescens | (Vasey) Wooton & Standl. | Poaceae | 8 |
| Tridens flavus | (L.) Hitchc. | Poaceae | 8 |
| Tridens texanus | (S.Watson) Nash | Poaceae | 8 |
| Tridentopsis mutica | (Torr.) P.M.Peterson | Poaceae | 8 |
| Trifolium amabile | Kunth | Fabaceae | 8 |
| Trifolium longipes | Nutt. | Fabaceae | 8 |
| Trifolium pinetorum | Greene | Fabaceae | 8 |
| Triglochin maritima | L. | Juncaginaceae | 8 |
| Triglochin scilloides | (Poir.) Mering & Kadereit | Juncaginaceae | 8 |
| Trigonospermum melampodioides | DC. | Asteraceae | 8 |
| Triodanis perfoliata | (L.) Nieuwl. | Campanulaceae | 8 |
| Triphora trianthophoros | (Sw.) Rydb. | Orchidaceae | 8 |
| Triplasiella eragrostoides | (Vasey & Scribn.) P.M.Peterson & Romasch. | Poaceae | 8 |
| Tripogandra amplexicaulis | (Klotzsch ex C.B.Clarke) Woodson | Commelinaceae | 8 |
| Tripogandra purpurascens | (S.Schauer) Handlos | Commelinaceae | 8 |
| Tripogandra serrulata | (Vahl) Handlos | Commelinaceae | 8 |
| Tripogonella spicata | (Nees) P.M.Peterson & Romasch. | Poaceae | 8 |
| Tripsacum dactyloides | (L.) L. | Poaceae | 8 |
| Triumfetta semitriloba | Jacq. | Malvaceae | 8 |
| Trixis californica | Kellogg | Asteraceae | 8 |
| Trixis inula | Crantz | Asteraceae | 8 |
| Trophis racemosa | (L.) Urb. | Moraceae | 8 |
| Turbinicarpus valdezianus | (H.Moeller) Glass & R.A.Foster | Cactaceae | 8 |
| Turnera callosa | Urb. | Passifloraceae | 8 |
| Turnera coerulea | Sessé & Moc. ex DC. | Passifloraceae | 8 |
| Turnera diffusa | Willd. ex Schult. | Passifloraceae | 8 |
| Turnera pumilea | L. | Passifloraceae | 8 |
| Turnera ulmifolia | L. | Passifloraceae | 8 |
| Turpinia occidentalis | (Sw.) G.Don | Staphyleaceae | 8 |
| Tutunakanthus velutinus | (Schltdl.) Morillo, Liede & Meve | Apocynaceae | 8 |
| Typha domingensis | Pers. | Typhaceae | 8 |
| Typha latifolia | L. | Typhaceae | 8 |
| Ulmus americana | L. | Ulmaceae | 8 |
| Ulmus crassifolia | Nutt. | Ulmaceae | 8 |
| Ulmus mexicana | (Liebm.) Planch. | Ulmaceae | 8 |
| Ungnadia speciosa | Endl. | Sapindaceae | 8 |
| Uniola paniculata | L. | Poaceae | 8 |
| Urbinella palmeri | Greenm. | Asteraceae | 8 |
| Urera baccifera | (L.) Gaudich. ex Wedd. | Urticaceae | 8 |
| Urera caracasana | (Jacq.) Gaudich. ex Griseb. | Urticaceae | 8 |
| Urera elata | (Sw.) Griseb. | Urticaceae | 8 |
| Urochloa arizonica | (Scribn. & Merr.) Morrone & Zuloaga | Poaceae | 8 |
| Urochloa ciliatissima | (Buckley) R.D.Webster | Poaceae | 8 |
| Urtica chamaedryoides | Pursh | Urticaceae | 8 |
| Urtica gracilenta | Greene | Urticaceae | 8 |
| Urtica gracilis | Aiton | Urticaceae | 8 |
| Urvillea ulmacea | Kunth | Sapindaceae | 8 |
| Utricularia foliosa | L. | Lentibulariaceae | 8 |
| Utricularia gibba | L. | Lentibulariaceae | 8 |
| Utricularia livida | E.Mey. | Lentibulariaceae | 8 |
| Utricularia macrorhiza | Leconte | Lentibulariaceae | 8 |
| Utricularia subulata | L. | Lentibulariaceae | 8 |
| Vaccinium cespitosum | Michx. | Ericaceae | 8 |
| Vaccinium leucanthum | Schltdl. | Ericaceae | 8 |
| Vaccinium stamineum | L. | Ericaceae | 8 |
| Vaccinium stenophyllum | Steud. | Ericaceae | 8 |
| Vachellia bravoensis | (Isely) Seigler & Ebinger | Fabaceae | 8 |
| Vachellia campeachiana | (Mill.) Seigler & Ebinger | Fabaceae | 8 |
| Vachellia constricta | (Benth.) Seigler & Ebinger | Fabaceae | 8 |
| Vachellia cornigera | (L.) Seigler & Ebinger | Fabaceae | 8 |
| Vachellia farnesiana | (L.) Wight & Arn. | Fabaceae | 8 |
| Vachellia glandulifera | (S.Watson) Seigler & Ebinger | Fabaceae | 8 |
| Vachellia macracantha | (Humb. & Bonpl. ex Willd.) Seigler & Ebinger | Fabaceae | 8 |
| Vachellia pennatula | (Schltdl. & Cham.) Seigler & Ebinger | Fabaceae | 8 |
| Vachellia rigidula | (Benth.) Seigler & Ebinger | Fabaceae | 8 |
| Vachellia schaffneri | (S.Watson) Seigler & Ebinger | Fabaceae | 8 |
| Vachellia vernicosa | (Britton & Rose) Seigler & Ebinger | Fabaceae | 8 |
| Valeriana clematitis | Kunth | Caprifoliaceae | 8 |
| Valeriana edulis | Nutt. | Caprifoliaceae | 8 |
| Valeriana scandens | L. | Caprifoliaceae | 8 |
| Valeriana sorbifolia | Kunth | Caprifoliaceae | 8 |
| Vallesia glabra | (Cav.) Link | Apocynaceae | 8 |
| Varilla texana | A.Gray | Asteraceae | 8 |
| Varronia curassavica | Jacq. | Cordiaceae | 8 |
| Varronia limicola | (Brandegee) Friesen | Cordiaceae | 8 |
| Varronia spinescens | (L.) Borhidi | Cordiaceae | 8 |
| Veratrum californicum | Durand | Melanthiaceae | 8 |
| Verbena bipinnatifida | (Nutt.) Schauer | Verbenaceae | 8 |
| Verbena bracteata | Cav. ex Lag. & Rodr. | Verbenaceae | 8 |
| Verbena canescens | Kunth | Verbenaceae | 8 |
| Verbena carolina | L. | Verbenaceae | 8 |
| Verbena elegans | Kunth | Verbenaceae | 8 |
| Verbena halei | Small | Verbenaceae | 8 |
| Verbena litoralis | Kunth | Verbenaceae | 8 |
| Verbena menthifolia | Benth. | Verbenaceae | 8 |
| Verbena neomexicana | (A.Gray) Briq. | Verbenaceae | 8 |
| Verbena perennis | Wooton | Verbenaceae | 8 |
| Verbena plicata | Greene | Verbenaceae | 8 |
| Verbena polyantha | (Umber) Moldenke | Verbenaceae | 8 |
| Verbena pumila | Rydb. | Verbenaceae | 8 |
| Verbena quadrangulata | A.Heller | Verbenaceae | 8 |
| Verbena racemosa | Eggert | Verbenaceae | 8 |
| Verbena recta | Kunth | Verbenaceae | 8 |
| Verbena scabra | Vahl | Verbenaceae | 8 |
| Verbena tumidula | L.M.Perry | Verbenaceae | 8 |
| Verbena xutha | Lehm. | Verbenaceae | 8 |
| Verbesina crocata | (Cav.) Less. | Asteraceae | 8 |
| Verbesina fastigiata | B.L.Rob. & Greenm. | Asteraceae | 8 |
| Verbesina lindheimeri | B.L.Rob. & Greenm. | Asteraceae | 8 |
| Verbesina longifolia | A.Gray | Asteraceae | 8 |
| Verbesina microptera | DC. | Asteraceae | 8 |
| Verbesina oncophora | B.L.Rob. & Seaton | Asteraceae | 8 |
| Verbesina parviflora | S.F.Blake | Asteraceae | 8 |
| Verbesina pedunculosa | (DC.) B.L.Rob. | Asteraceae | 8 |
| Verbesina persicifolia | DC. | Asteraceae | 8 |
| Verbesina robinsonii | Fernald | Asteraceae | 8 |
| Verbesina rothrockii | B.L.Rob. & Greenm. | Asteraceae | 8 |
| Verbesina serrata | Cav. | Asteraceae | 8 |
| Verbesina sphaerocephala | A.Gray | Asteraceae | 8 |
| Verbesina tetraptera | A.Gray | Asteraceae | 8 |
| Verbesina turbacensis | Kunth | Asteraceae | 8 |
| Verbesina virgata | Cav. | Asteraceae | 8 |
| Vernonanthura patens | (Kunth) H.Rob. | Asteraceae | 8 |
| Vernonia greggii | A.Gray | Asteraceae | 8 |
| Vernonia lindheimeri | A.Gray & Engelm. | Asteraceae | 8 |
| Vernonia paniculata | DC. | Asteraceae | 8 |
| Veronica americana | (Raf.) Schwein. ex Benth. | Plantaginaceae | 8 |
| Veronica peregrina | L. | Plantaginaceae | 8 |
| Veronica plantaginea | E.James | Plantaginaceae | 8 |
| Viburnum rufidulum | Raf. | Viburnaceae | 8 |
| Vicia americana | Muhl. ex Willd. | Fabaceae | 8 |
| Vicia ludoviciana | Nutt. | Fabaceae | 8 |
| Vicia pulchella | Kunth | Fabaceae | 8 |
| Vigethia mexicana | (S.Watson) W.A.Weber | Asteraceae | 8 |
| Vigna luteola | (Jacq.) Benth. | Fabaceae | 8 |
| Viguiera dentata | (Cav.) Spreng. | Asteraceae | 8 |
| Viguiera linearis | (Cav.) Sch.Bip. ex Hemsl. | Asteraceae | 8 |
| Villadia cucullata | Rose | Crassulaceae | 8 |
| Viola adunca | Sm. | Violaceae | 8 |
| Viola nephrophylla | Greene | Violaceae | 8 |
| Viola palmata | L. | Violaceae | 8 |
| Viola sororia | Willd. | Violaceae | 8 |
| Vitex mollis | Kunth | Lamiaceae | 8 |
| Vitex pyramidata | B.L.Rob. | Lamiaceae | 8 |
| Vitis arizonica | Engelm. | Vitaceae | 8 |
| Vitis berlandieri | Planch. | Vitaceae | 8 |
| Vitis cinerea | (Engelm.) Millardet | Vitaceae | 8 |
| Vitis mustangensis | Buckley | Vitaceae | 8 |
| Vitis riparia | Michx. | Vitaceae | 8 |
| Vitis rotundifolia | Michx. | Vitaceae | 8 |
| Vitis tiliifolia | Humb. & Bonpl. ex Schult. | Vitaceae | 8 |
| Vittaria lineata | (L.) Sm. | Pteridaceae | 8 |
| Waltheria acuminata | Rose | Malvaceae | 8 |
| Waltheria indica | L. | Malvaceae | 8 |
| Wedelia acapulcensis | Kunth | Asteraceae | 8 |
| Weldenia candida | Schult.f. | Commelinaceae | 8 |
| Wigandia urens | (Ruiz & Pav.) Kunth | Namaceae | 8 |
| Wimmeria microphylla | Radlk. | Celastraceae | 8 |
| Wimmeria persicifolia | Radlk. | Celastraceae | 8 |
| Wissadula amplissima | (L.) R.E.Fr. | Malvaceae | 8 |
| Witheringia mexicana | (B.L.Rob.) Hunz. | Solanaceae | 8 |
| Witheringia solanacea | L'Hér. | Solanaceae | 8 |
| Wolffia brasiliensis | Wedd. | Araceae | 8 |
| Wolffia columbiana | H.Karst. | Araceae | 8 |
| Woodsia neomexicana | Windham | Woodsiaceae | 8 |
| Woodsia phillipsii | Windham | Woodsiaceae | 8 |
| Xanthisma gracile | (Nutt.) D.R.Morgan & R.L.Hartm. | Asteraceae | 8 |
| Xanthisma spinulosum | (Pursh) D.R.Morgan & R.L.Hartm. | Asteraceae | 8 |
| Xanthium orientale | L. | Asteraceae | 8 |
| Xanthium spinosum | L. | Asteraceae | 8 |
| Xanthocephalum gymnospermoides | (A.Gray) Benth. & Hook.f. | Asteraceae | 8 |
| Ximenia americana | L. | Olacaceae | 8 |
| Xylorhiza wrightii | Greene | Asteraceae | 8 |
| Xylosma flexuosa | (Kunth) Hemsl. | Salicaceae | 8 |
| Xyris ambigua | Beyr. ex Kunth | Xyridaceae | 8 |
| Xyris jupicai | Rich. | Xyridaceae | 8 |
| Xyris stricta | Chapm. | Xyridaceae | 8 |
| Yucca baccata | Torr. | Asparagaceae | 8 |
| Yucca carnerosana | (Trel.) McKelvey | Asparagaceae | 8 |
| Yucca constricta | Buckley | Asparagaceae | 8 |
| Yucca decipiens | Trel. | Asparagaceae | 8 |
| Yucca elata | (Engelm.) Engelm. | Asparagaceae | 8 |
| Yucca endlichiana | Trel. | Asparagaceae | 8 |
| Yucca faxoniana | (Trel.) Sarg. | Asparagaceae | 8 |
| Yucca filifera | Chabaud | Asparagaceae | 8 |
| Yucca madrensis | Gentry | Asparagaceae | 8 |
| Yucca reverchonii | Trel. | Asparagaceae | 8 |
| Yucca rostrata | Engelm. ex Trel. | Asparagaceae | 8 |
| Yucca rupicola | Scheele | Asparagaceae | 8 |
| Yucca thompsoniana | Trel. | Asparagaceae | 8 |
| Zaluzania augusta | (Lag.) Sch.Bip. | Asteraceae | 8 |
| Zaluzania triloba | (Ortega) Pers. | Asteraceae | 8 |
| Zamia loddigesii | Miq. | Zamiaceae | 8 |
| Zannichellia palustris | L. | Potamogetonaceae | 8 |
| Zanthoxylum americanum | Mill. | Rutaceae | 8 |
| Zanthoxylum arborescens | Rose | Rutaceae | 8 |
| Zanthoxylum clava-herculis | L. | Rutaceae | 8 |
| Zanthoxylum fagara | Sarg. | Rutaceae | 8 |
| Zanthoxylum melanostictum | Schltdl. & Cham. | Rutaceae | 8 |
| Zapoteca formosa | (Kunth) H.M.Hern. | Fabaceae | 8 |
| Zeltnera arizonica | (A.Gray) G.Mans. | Gentianaceae | 8 |
| Zeltnera beyrichii | (Torr.) G.Mans. | Gentianaceae | 8 |
| Zeltnera calycosa | (Buckley) G.Mans. | Gentianaceae | 8 |
| Zeltnera exaltata | (Griseb.) G.Mans. | Gentianaceae | 8 |
| Zeltnera texensis | (Griseb.) G.Mans. ex J.S.Pringle | Gentianaceae | 8 |
| Zeltnera venusta | (A.Gray) G.Mans. | Gentianaceae | 8 |
| Zephyranthes carinata | Herb. | Amaryllidaceae | 8 |
| Zephyranthes chlorosolen | (Herb.) D.Dietr. | Amaryllidaceae | 8 |
| Zephyranthes drummondii | D.Don | Amaryllidaceae | 8 |
| Zephyranthes fosteri | Traub | Amaryllidaceae | 8 |
| Zephyranthes minuta | (Kunth) D.Dietr. | Amaryllidaceae | 8 |
| Zephyranthes pulchella | J.G.Sm. | Amaryllidaceae | 8 |
| Zinnia acerosa | (DC.) A.Gray | Asteraceae | 8 |
| Zinnia bicolor | Hemsl. | Asteraceae | 8 |
| Zinnia elegans | Jacq. | Asteraceae | 8 |
| Zinnia grandiflora | Nutt. | Asteraceae | 8 |
| Zinnia juniperifolia | A.Gray | Asteraceae | 8 |
| Zinnia maritima | Kunth | Asteraceae | 8 |
| Zinnia peruviana | (L.) L. | Asteraceae | 8 |
| Zinnia zinnioides | (Kunth) Olorode & A.M.Torres | Asteraceae | 8 |
| Zornia latifolia | Sm. | Fabaceae | 8 |
| Zornia reticulata | Sm. | Fabaceae | 8 |
| Zornia thymifolia | Kunth | Fabaceae | 8 |
| Zuloagaea bulbosa | (Kunth) Bess | Poaceae | 8 |
| Abutilon californicum | Benth. | Malvaceae | 7 |
| Achimenes flava | C.V.Morton | Gesneriaceae | 7 |
| Acourtia platyphylla | (A.Gray) Reveal & R.M.King | Asteraceae | 7 |
| Agalinis peduncularis | (Benth.) Pennell | Orobanchaceae | 7 |
| Agarista mexicana | (Hemsl.) Judd | Ericaceae | 7 |
| Agave funkiana | K.Koch & C.D.Bouché | Asparagaceae | 7 |
| Ageratina brevipes | (DC.) R.M.King & H.Rob. | Asteraceae | 7 |
| Aldama ghiesbreghtii | (Hemsl.) E.E.Schill. & Panero | Asteraceae | 7 |
| Aphananthe monoica | (Hemsl.) J.-F.Leroy | Cannabaceae | 7 |
| Aporocactus flagelliformis | (L.) Lem. | Cactaceae | 7 |
| Aquilegia skinneri | Hook. | Ranunculaceae | 7 |
| Arcytophyllum fasciculatum | (A.Gray) Terrell & H.Rob. | Rubiaceae | 7 |
| Aristolochia pringlei | Rose | Aristolochiaceae | 7 |
| Asclepias mexicana | Cav. | Apocynaceae | 7 |
| Asclepias sauronii | M.G.Chávez & L.O.Alvarado | Apocynaceae | 7 |
| Astragalus giganteus | S.Watson | Fabaceae | 7 |
| Astragalus guatemalensis | Hemsl. | Fabaceae | 7 |
| Astragalus pringlei | S.Watson | Fabaceae | 7 |
| Astrolepis crassifolia | (Houlston & T.Moore) D.M.Benham & Windham | Pteridaceae | 7 |
| Aztecaster matudae | (Rzed.) G.L.Nesom | Asteraceae | 7 |
| Aztekium hintonii | Glass & W.A.Fitz Maur. | Cactaceae | 7 |
| Baccharis bigelovii | A.Gray | Asteraceae | 7 |
| Bauhinia ramosissima | Benth. ex Hemsl. | Fabaceae | 7 |
| Begonia oaxacana | A.DC. | Begoniaceae | 7 |
| Berberis alpina | Zamudio | Berberidaceae | 7 |
| Bernardia mexicana | (Hook. & Arn.) Müll.Arg. | Euphorbiaceae | 7 |
| Bidens anthemoides | Sherff | Asteraceae | 7 |
| Blepharidachne bigelovii | (S.Watson) Hack. | Poaceae | 7 |
| Bletia brevicaulis | (L.O.Williams) Sosa & M.W.Chase | Orchidaceae | 7 |
| Boerhavia ciliata | Brandegee | Nyctaginaceae | 7 |
| Boerhavia spicata | Choisy | Nyctaginaceae | 7 |
| Bouteloua radicosa | (E.Fourn.) Griffiths | Poaceae | 7 |
| Brahea decumbens | Rzed. | Arecaceae | 7 |
| Brickellia brachyphylla | (A.Gray) A.Gray | Asteraceae | 7 |
| Bromus marginatus | Nees ex Steud. | Poaceae | 7 |
| Brongniartia intermedia | Moric. | Fabaceae | 7 |
| Bursera linanoe | (La Llave) Rzed., Calderón & Medina | Burseraceae | 7 |
| Bursera submoniliformis | Engl. | Burseraceae | 7 |
| Carlowrightia hapalocarpa | B.L.Rob. & Greenm. | Acanthaceae | 7 |
| Casearia aculeata | Jacq. | Salicaceae | 7 |
| Casimiroa greggii | (S.Watson) F.Chiang | Rutaceae | 7 |
| Castilleja bella | Standl. | Orobanchaceae | 7 |
| Centrosema sagittatum | (Humb. & Bonpl. ex Willd.) Brandegee | Fabaceae | 7 |
| Chaetymenia peduncularis | Hook. & Arn. | Asteraceae | 7 |
| Chloris radiata | (L.) Sw. | Poaceae | 7 |
| Christella hispidula | (Decne.) Holttum | Thelypteridaceae | 7 |
| Chrysanthellum indicum | DC. | Asteraceae | 7 |
| Cirsium anartiolepis | Petr. | Asteraceae | 7 |
| Cissampelos tropaeolifolia | DC. | Menispermaceae | 7 |
| Clethra lanata | M.Martens & Galeotti | Clethraceae | 7 |
| Cochemiea barbata | (Engelm.) Doweld | Cactaceae | 7 |
| Commelina elliptica | Kunth | Commelinaceae | 7 |
| Condalia mexicana | Schltdl. | Rhamnaceae | 7 |
| Corispermum americanum | (Nutt.) Nutt. | Chenopodiaceae | 7 |
| Cosmos palmeri | B.L.Rob. | Asteraceae | 7 |
| Crepis runcinata | (E.James) Torr. & A.Gray | Asteraceae | 7 |
| Croton pseudoniveus | Lundell | Euphorbiaceae | 7 |
| Cynanchum foetidum | (Cav.) Kunth | Apocynaceae | 7 |
| Cyperus hortensis | (Salzm. ex Steud.) Dorr | Cyperaceae | 7 |
| Cyperus pallidicolor | (Kük.) G.C.Tucker | Cyperaceae | 7 |
| Dalea filiformis | A.Gray | Fabaceae | 7 |
| Dasylirion quadrangulatum | S.Watson | Asparagaceae | 7 |
| Desmanthus obtusus | S.Watson | Fabaceae | 7 |
| Didiplis diandra | (Nutt. ex DC.) Alph.Wood | Lythraceae | 7 |
| Dioon tomasellii | De Luca, Sabato & Vázq.Torres | Zamiaceae | 7 |
| Diplopterygium bancroftii | (Hook.) A.R.Sm. | Gleicheniaceae | 7 |
| Drymaria pachyphylla | Wooton & Standl. | Caryophyllaceae | 7 |
| Echinocereus dasyacanthus | Engelm. | Cactaceae | 7 |
| Eleocharis bonariensis | Nees | Cyperaceae | 7 |
| Elionurus barbiculmis | Hack. ex Scribn. | Poaceae | 7 |
| Epidendrum cristatum | Ruiz & Pav. | Orchidaceae | 7 |
| Eriochloa acuminata | (J.Presl) Kunth | Poaceae | 7 |
| Eryngium cymosum | F.Delaroche | Apiaceae | 7 |
| Euphorbia beamanii | M.C.Johnst. | Euphorbiaceae | 7 |
| Euphorbia greggii | Boiss. | Euphorbiaceae | 7 |
| Festuca saximontana | Rydb. | Poaceae | 7 |
| Flyriella parryi | (A.Gray) R.M.King & H.Rob. | Asteraceae | 7 |
| Frangula betulifolia | (Greene) Grubov | Rhamnaceae | 7 |
| Galphimia paniculata | Bartl. | Malpighiaceae | 7 |
| Gentiana laevigata | M.Martens & Galeotti | Gentianaceae | 7 |
| Geranium bellum | Rose | Geraniaceae | 7 |
| Gnaphaliothamnus salicifolius | (Bertol.) G.L.Nesom | Asteraceae | 7 |
| Gomphrena nitida | Rothr. | Amaranthaceae | 7 |
| Gonolobus jaliscensis | B.L.Rob. & Greenm. | Apocynaceae | 7 |
| Habenaria jaliscana | S.Watson | Orchidaceae | 7 |
| Hackelia mexicana | (Schltdl. & Cham.) I.M.Johnst. | Boraginaceae | 7 |
| Harpalyce formosa | DC. | Fabaceae | 7 |
| Hedeoma jucunda | Greene | Lamiaceae | 7 |
| Helianthus paradoxus | Heiser | Asteraceae | 7 |
| Hibiscus biseptus | S.Watson | Malvaceae | 7 |
| Hymenocallis durangoensis | T.M.Howard | Amaryllidaceae | 7 |
| Ipomoea neurocephala | Hallier f. | Convolvulaceae | 7 |
| Ipomoea setosa | Ker Gawl. | Convolvulaceae | 7 |
| Jaegeria bellidiflora | (Moc. & Sessé ex DC.) A.M.Torres & Beaman | Asteraceae | 7 |
| Juniperus poblana | (Martínez) R.P.Adams | Cupressaceae | 7 |
| Lasiacis nigra | Davidse | Poaceae | 7 |
| Lasianthaea palmeri | (Greenm.) K.M.Becker | Asteraceae | 7 |
| Leucactinia bracteata | Rydb. | Asteraceae | 7 |
| Leucaena greggii | S.Watson | Fabaceae | 7 |
| Lisianthius axillaris | (Hemsl.) Kuntze | Gentianaceae | 7 |
| Lonchocarpus guatemalensis | Benth. | Fabaceae | 7 |
| Machaonia erythrocarpa | (Standl.) Borhidi | Rubiaceae | 7 |
| Malaxis excavata | (Lindl.) Kuntze | Orchidaceae | 7 |
| Malaxis maianthemifolia | Schltdl. & Cham. | Orchidaceae | 7 |
| Mariosousa millefolia | (S.Watson) Seigler & Ebinger | Fabaceae | 7 |
| Melampodium longicorne | A.Gray | Asteraceae | 7 |
| Moussonia jaliscana | (S.Watson) D.L.Denham ex Ram.-Roa | Gesneriaceae | 7 |
| Muhlenbergia villiflora | Hitchc. | Poaceae | 7 |
| Myriocarpa longipes | Liebm. | Urticaceae | 7 |
| Nicolletia edwardsii | A.Gray | Asteraceae | 7 |
| Olyra latifolia | L. | Poaceae | 7 |
| Oncaglossum pringlei | (Greenm.) Sutorý | Boraginaceae | 7 |
| Ophioglossum nudicaule | L.f. | Ophioglossaceae | 7 |
| Pachyphytum hookeri | (Salm-Dyck) A.Berger | Crassulaceae | 7 |
| Paronychia wilkinsonii | S.Watson | Caryophyllaceae | 7 |
| Parthenium argentatum | A.Gray | Asteraceae | 7 |
| Passiflora serratifolia | L. | Passifloraceae | 7 |
| Phyllonoma laticuspis | (Turcz.) Engl. | Phyllonomaceae | 7 |
| Physalis caudella | Standl. | Solanaceae | 7 |
| Physostegia correllii | (Lundell) Shinners | Lamiaceae | 7 |
| Pinguicula crassifolia | Zamudio | Lentibulariaceae | 7 |
| Pinus luzmariae | Pérez de la Rosa | Pinaceae | 7 |
| Plantago eriopoda | Torr. | Plantaginaceae | 7 |
| Plantago linearis | Kunth | Plantaginaceae | 7 |
| Populus mexicana | Wesm. | Salicaceae | 7 |
| Pseudalcantarea viridiflora | (Beer) Pinzón & Barfuss | Bromeliaceae | 7 |
| Pseudognaphalium viscosum | (Kunth) Anderb. | Asteraceae | 7 |
| Psychotria biaristata | Bartl. ex DC. | Rubiaceae | 7 |
| Ptilagrostiella kingii | (Bol.) Romasch. | Poaceae | 7 |
| Quercus crassipes | Bonpl. | Fagaceae | 7 |
| Randia cookii | Standl. | Rubiaceae | 7 |
| Ruellia intermedia | Leonard | Acanthaceae | 7 |
| Sageretia wrightii | S.Watson | Rhamnaceae | 7 |
| Salvia recurva | Benth. | Lamiaceae | 7 |
| Salvia summa | A.Nelson | Lamiaceae | 7 |
| Salvia whitehousei | Alziar | Lamiaceae | 7 |
| Securidaca diversifolia | (L.) S.F.Blake | Polygalaceae | 7 |
| Sedum confusum | Hemsl. | Crassulaceae | 7 |
| Senecio riddellii | Torr. & A.Gray | Asteraceae | 7 |
| Senegalia crassifolia | (A.Gray) Britton & Rose | Fabaceae | 7 |
| Senna quinquangulata | (Rich.) H.S.Irwin & Barneby | Fabaceae | 7 |
| Serjania cardiospermoides | Schltdl. & Cham. | Sapindaceae | 7 |
| Sida neomexicana | A.Gray | Malvaceae | 7 |
| Sisyrinchium pringlei | B.L.Rob. & Greenm. | Iridaceae | 7 |
| Solanum tampicense | Dunal | Solanaceae | 7 |
| Spermolepis divaricata | (Walter) Raf. | Apiaceae | 7 |
| Stenocactus multicostatus | (Hildm. ex K.Schum.) A.Berger | Cactaceae | 7 |
| Struthanthus interruptus | G.Don | Loranthaceae | 7 |
| Suaeda tampicensis | (Standl.) Standl. | Chenopodiaceae | 7 |
| Talayotea trachyantha | (Greenm.) L.O.Alvarado | Apocynaceae | 7 |
| Tephrosia nicaraguensis | Oerst. | Fabaceae | 7 |
| Tetranema roseum | (M.Martens & Galeotti) Standl. & Steyerm. | Plantaginaceae | 7 |
| Trichocoronis wrightii | A.Gray | Asteraceae | 7 |
| Tripogandra disgrega | (Kunth) Woodson | Commelinaceae | 7 |
| Trixis anomala | B.L.Turner | Asteraceae | 7 |
| Vaccinium geminiflorum | Kunth | Ericaceae | 7 |
| Verbesina ovatifolia | A.Gray ex Hemsl. | Asteraceae | 7 |
| Villadia aristata | Moran | Crassulaceae | 7 |
| Viola barroetana | Schaffn. ex Hemsl. | Violaceae | 7 |
| Woodwardia spinulosa | M.Martens & Galeotti | Blechnaceae | 7 |
| Zeltnera pusilla | (Eastw.) G.Mans. | Gentianaceae | 7 |
| Zephyranthes morrisclintii | Traub & T.M.Howard | Amaryllidaceae | 7 |
| Acianthera circumplexa | (Lindl.) Pridgeon & M.W.Chase | Orchidaceae | 6 |
| Acleisanthes crassifolia | A.Gray | Nyctaginaceae | 6 |
| Adiantum tetraphyllum | Humb. & Bonpl. ex Willd. | Pteridaceae | 6 |
| Agastache breviflora | (A.Gray) Epling | Lamiaceae | 6 |
| Agave gracilipes | Trel. | Asparagaceae | 6 |
| Ageratina vernalis | (Vatke & Kurtz) R.M.King & H.Rob. | Asteraceae | 6 |
| Allium glandulosum | Link & Otto | Amaryllidaceae | 6 |
| Alloispermum scabrum | (Lag.) H.Rob. | Asteraceae | 6 |
| Amaranthus arenicola | I.M.Johnst. | Amaranthaceae | 6 |
| Anticlea hintoniorum | (B.L.Turner) Zomlefer & Judd | Melanthiaceae | 6 |
| Antiphytum heliotropioides | A.DC. | Boraginaceae | 6 |
| Aporocactus martianus | (Zucc.) Britton & Rose | Cactaceae | 6 |
| Arenaria bourgaei | Hemsl. | Caryophyllaceae | 6 |
| Argyrochosma formosa | (Liebm.) Windham | Pteridaceae | 6 |
| Ariocarpus scaphirostrus | Boed. | Cactaceae | 6 |
| Arpophyllum laxiflorum | Pfitzer | Orchidaceae | 6 |
| Asclepias pringlei | (Greenm.) Woodson | Apocynaceae | 6 |
| Asclepias virletii | E.Fourn. | Apocynaceae | 6 |
| Asclepias zanthodacryon | (L.B.Sm.) Woodson | Apocynaceae | 6 |
| Asemeia apopetala | (Brandegee) J.F.B.Pastore & J.R.Abbott | Polygalaceae | 6 |
| Aspicarpa brevipes | (DC.) W.R.Anderson | Malpighiaceae | 6 |
| Atriplex cristata | Humb. & Bonpl. ex Willd. | Chenopodiaceae | 6 |
| Baccharis sulcata | DC. | Asteraceae | 6 |
| Bacopa rotundifolia | (Michx.) Wettst. | Plantaginaceae | 6 |
| Begonia pinetorum | A.DC. | Begoniaceae | 6 |
| Berberis eutriphylla | (Fedde) C.H.Mull. | Berberidaceae | 6 |
| Berberis moranensis | Hebenstr. & Ludw. ex Schult. & Schult.f. | Berberidaceae | 6 |
| Blanchardia clypeata | (L.) M.M.Hanes & R.L.Barrett | Malvaceae | 6 |
| Bouteloua diversispicula | Columbus | Poaceae | 6 |
| Buchnera obliqua | Benth. | Orobanchaceae | 6 |
| Cakile geniculata | (B.L.Rob.) Millsp. | Brassicaceae | 6 |
| Canavalia brasiliensis | Mart. ex Benth. | Fabaceae | 6 |
| Carex boliviensis | Van Heurck & Müll.Arg. | Cyperaceae | 6 |
| Carex oreocharis | Holm | Cyperaceae | 6 |
| Castilleja nervata | Eastw. | Orobanchaceae | 6 |
| Chamaedorea microspadix | Burret | Arecaceae | 6 |
| Chiococca oaxacana | Standl. | Rubiaceae | 6 |
| Chrysactinia truncata | S.Watson | Asteraceae | 6 |
| Cirsium turneri | Warnock | Asteraceae | 6 |
| Clematis polygama | Jacq. | Ranunculaceae | 6 |
| Clethra hartwegii | Britton | Clethraceae | 6 |
| Cochlospermum malvifolium | (A.Gray) Byng & Christenh. | Bixaceae | 6 |
| Colubrina heteroneura | (Griseb.) Standl. | Rhamnaceae | 6 |
| Coryphantha cornifera | (DC.) Lem. | Cactaceae | 6 |
| Coryphantha ottonis | (Pfeiff.) Lem. | Cactaceae | 6 |
| Coryphantha vogtherriana | Werderm. & Boed. | Cactaceae | 6 |
| Cosmos concolor | Sherff | Asteraceae | 6 |
| Costus villosissimus | Jacq. | Costaceae | 6 |
| Crossopetalum parviflorum | (Hemsl.) Lundell | Celastraceae | 6 |
| Crotalaria longirostrata | Hook. & Arn. | Fabaceae | 6 |
| Croton argenteus | L. | Euphorbiaceae | 6 |
| Cumarinia odorata | (Boed.) Buxb. | Cactaceae | 6 |
| Cuphea lanceolata | W.T.Aiton | Lythraceae | 6 |
| Cyclanthera langaei | Cogn. | Cucurbitaceae | 6 |
| Cyperus amabilis | Vahl | Cyperaceae | 6 |
| Descurainia adenophora | (Wooton & Standl.) O.E.Schulz | Brassicaceae | 6 |
| Desmodium densiflorum | Hemsl. | Fabaceae | 6 |
| Dianthera laevilinguis | (Nees) Lindau | Acanthaceae | 6 |
| Drymaria xerophylla | A.Gray | Caryophyllaceae | 6 |
| Echinocactus horizonthalonius | Lem. | Cactaceae | 6 |
| Echinopterys eglandulosa | (A.Juss.) Small | Malpighiaceae | 6 |
| Epithelantha ilariae | D.Donati & Zanov. | Cactaceae | 6 |
| Eragrostis capillaris | (L.) Nees | Poaceae | 6 |
| Eryngium gracile | F.Delaroche | Apiaceae | 6 |
| Erythrina standleyana | Krukoff | Fabaceae | 6 |
| Euphorbia bracteata | Jacq. | Euphorbiaceae | 6 |
| Euphorbia tanquahuete | Sessé & Moc. | Euphorbiaceae | 6 |
| Euploca fruticosa | (L.) J.I.M.Melo & Semir | Heliotropiaceae | 6 |
| Festuca thurberi | Vasey | Poaceae | 6 |
| Gaillardia coahuilensis | B.L.Turner | Asteraceae | 6 |
| Galeana pratensis | Rydb. | Asteraceae | 6 |
| Gnaphalium exilifolium | A.Nelson | Asteraceae | 6 |
| Govenia capitata | Lindl. | Orchidaceae | 6 |
| Graptopetalum rusbyi | Rose | Crassulaceae | 6 |
| Grindelia arizonica | A.Gray | Asteraceae | 6 |
| Halenia palmeri | A.Gray | Gentianaceae | 6 |
| Halodule wrightii | Asch. | Cymodoceaceae | 6 |
| Heuchera longipetala | Moc. ex Ser. | Saxifragaceae | 6 |
| Heuchera mexicana | W.Schaffn. ex Rydb. | Saxifragaceae | 6 |
| Hymenothrix glandulopubescens | (Waterf.) B.G.Baldwin | Asteraceae | 6 |
| Hypoxis mexicana | Schult. & Schult.f. | Hypoxidaceae | 6 |
| Indigofera sphaerocarpa | A.Gray | Fabaceae | 6 |
| Iostephane madrensis | (S.Watson) Strother | Asteraceae | 6 |
| Ipomoea reticulata | O'Donell | Convolvulaceae | 6 |
| Jatropha gaumeri | Greenm. | Euphorbiaceae | 6 |
| Juniperus monticola | Martínez | Cupressaceae | 6 |
| Justicia carthaginensis | Jacq. | Acanthaceae | 6 |
| Lasianthaea macrocephala | (Hook. & Arn.) K.M.Becker | Asteraceae | 6 |
| Laubertia contorta | (M.Martens & Galeotti) Woodson | Apocynaceae | 6 |
| Leucaena lanceolata | S.Watson | Fabaceae | 6 |
| Leucophyllum laevigatum | Standl. | Scrophulariaceae | 6 |
| Linum scabrellum | Planch. | Linaceae | 6 |
| Lycianthes dejecta | (Fernald) Bitter | Solanaceae | 6 |
| Lycianthes surotatensis | Gentry | Solanaceae | 6 |
| Lythrum vulneraria | Ait. ex Schrank | Lythraceae | 6 |
| Mammillaria melanocentra | Poselg. | Cactaceae | 6 |
| Mammillaria plumosa | F.A.C.Weber | Cactaceae | 6 |
| Mammillaria prolifera | (Mill.) Haw. | Cactaceae | 6 |
| Marsilea mollis | B.L.Rob. & Fernald | Marsileaceae | 6 |
| Maxillaria meleagris | Lindl. | Orchidaceae | 6 |
| Menodora intricata | Brandegee | Oleaceae | 6 |
| Mentzelia reverchonii | (Urb. & Gilg) H.J.Thomps. & Zavort. | Loasaceae | 6 |
| Metastelma pringlei | A.Gray | Apocynaceae | 6 |
| Miconia guatemalensis | Cogn. ex Donn.Sm. | Melastomataceae | 6 |
| Miconia oligotricha | (DC.) Naudin | Melastomataceae | 6 |
| Microchloa kunthii | Desv. | Poaceae | 6 |
| Micropleura renifolia | Lag. | Apiaceae | 6 |
| Mimosa depauperata | Benth. | Fabaceae | 6 |
| Mimosa galeottii | Benth. | Fabaceae | 6 |
| Mimosa latidens | (Small) B.L.Turner | Fabaceae | 6 |
| Mirabilis triflora | Benth. | Nyctaginaceae | 6 |
| Myrcia bartlettii | (Standl.) A.R.Lourenço & Sánchez-Cháv. | Myrtaceae | 6 |
| Nama origanifolia | Kunth | Namaceae | 6 |
| Neopringlea integrifolia | (Hemsl.) S.Watson | Salicaceae | 6 |
| Notholaena greggii | (Mett. ex Kuhn) Maxon | Pteridaceae | 6 |
| Oxylobus arbutifolius | (Kunth) A.Gray | Asteraceae | 6 |
| Pachyphytum compactum | Rose | Crassulaceae | 6 |
| Packera bellidifolia | (Kunth) W.A.Weber & Á.Löve | Asteraceae | 6 |
| Pauciflora sagittifolia | (A.Gray) Morillo, Liede & Meve | Apocynaceae | 6 |
| Pelecyphora sneedii | (Britton & Rose) D.Aquino & Dan.Sánchez | Cactaceae | 6 |
| Penstemon amphorellae | Crosswh. | Plantaginaceae | 6 |
| Penstemon wislizeni | (A.Gray) Straw | Plantaginaceae | 6 |
| Peperomia hispidula | (Sw.) A.Dietr. | Piperaceae | 6 |
| Phalaris angusta | Nees ex Trin. | Poaceae | 6 |
| Piqueria pilosa | Kunth | Asteraceae | 6 |
| Plantago argyrea | E.Morris | Plantaginaceae | 6 |
| Polemonium grandiflorum | Benth. | Polemoniaceae | 6 |
| Poliomintha marifolia | (S.Schauer) A.Gray | Lamiaceae | 6 |
| Polypodium rhodopleuron | Kunze | Polypodiaceae | 6 |
| Prockia crucis | P.Browne ex L. | Salicaceae | 6 |
| Quercus scytophylla | Liebm. | Fagaceae | 6 |
| Roldana reticulata | (DC.) H.Rob. & Brettell | Asteraceae | 6 |
| Russelia retrorsa | Greene | Plantaginaceae | 6 |
| Sageretia elegans | (Kunth) Brongn. | Rhamnaceae | 6 |
| Salmea scandens | (L.) DC. | Asteraceae | 6 |
| Sapium macrocarpum | Müll.Arg. | Euphorbiaceae | 6 |
| Schistocarpha bicolor | Less. | Asteraceae | 6 |
| Schultesia guianensis | (Aubl.) Malme | Gentianaceae | 6 |
| Sedum liebmannianum | Hemsl. | Crassulaceae | 6 |
| Selaginella viridissima | Weath. | Selaginellaceae | 6 |
| Senna orcuttii | (Britton & Rose) H.S.Irwin & Barneby | Fabaceae | 6 |
| Senna polyphylla | (Jacq.) H.S.Irwin & Barneby | Fabaceae | 6 |
| Setaria macrosperma | (Scribn. & Merr.) K.Schum. | Poaceae | 6 |
| Seymeria bipinnatisecta | Seem. | Orobanchaceae | 6 |
| Sigmoidotropis speciosa | (Kunth) A.Delgado | Fabaceae | 6 |
| Sporobolus purpurascens | (Sw.) Ham. | Poaceae | 6 |
| Stevia caracasana | DC. | Asteraceae | 6 |
| Stevia jorullensis | Kunth | Asteraceae | 6 |
| Sticherus furcatus | (L.) Ching | Gleicheniaceae | 6 |
| Tetraneuris turneri | (K.F.Parker) K.F.Parker | Asteraceae | 6 |
| Tillandsia albida | Mez & Purpus | Bromeliaceae | 6 |
| Tinantia violacea | Rohweder | Commelinaceae | 6 |
| Toxicodendron striatum | Kuntze | Anacardiaceae | 6 |
| Tragia volubilis | L. | Euphorbiaceae | 6 |
| Trichocentrum brachyphyllum | (Lindl.) R.Jiménez | Orchidaceae | 6 |
| Trichoneura elegans | Swallen | Poaceae | 6 |
| Trixis angustifolia | DC. | Asteraceae | 6 |
| Trixis hyposericea | S.Watson | Asteraceae | 6 |
| Trixis mexicana | Lex. | Asteraceae | 6 |
| Urostephanus gonoloboides | B.L.Rob. & Greenm. | Apocynaceae | 6 |
| Valeriana selerorum | Graebn. & Loes. | Caprifoliaceae | 6 |
| Varronia bullata | L. | Cordiaceae | 6 |
| Vasconcellea cauliflora | (Jacq.) A.DC. | Caricaceae | 6 |
| Verbesina longipes | Hemsl. | Asteraceae | 6 |
| Viguiera excelsa | (Willd.) Benth. & Hook.f. | Asteraceae | 6 |
| Viola nannei | Pol. | Violaceae | 6 |
| Vittaria graminifolia | Kaulf. | Pteridaceae | 6 |
| Wedelia mexicana | (Sch.Bip.) McVaugh | Asteraceae | 6 |
| Woodsia plummerae | Lemmon | Woodsiaceae | 6 |
| Yucca jaliscensis | (Trel.) Trel. | Asparagaceae | 6 |
| Zamia fischeri | Miq. ex Lem. | Zamiaceae | 6 |
| Zapoteca media | (M.Martens & Galeotti) H.M.Hern. | Fabaceae | 6 |
| Zinnia angustifolia | Kunth | Asteraceae | 6 |
| Abies durangensis | Martínez | Pinaceae | 5 |
| Abutilon hulseanum | (Torr. & A.Gray) Torr. ex Baker f. | Malvaceae | 5 |
| Achimenes occidentalis | C.V.Morton | Gesneriaceae | 5 |
| Aeschynomene rudis | Benth. | Fabaceae | 5 |
| Agave maximiliana | Baker | Asparagaceae | 5 |
| Agave obscura | Schiede ex Schltdl. | Asparagaceae | 5 |
| Agave scabra | Ortega | Asparagaceae | 5 |
| Agave singuliflora | (S.Watson) A.Berger | Asparagaceae | 5 |
| Alchemilla aphanoides | Mutis ex L.f. | Rosaceae | 5 |
| Anoda leonensis | Fryxell | Malvaceae | 5 |
| Anoda palmata | Fryxell | Malvaceae | 5 |
| Antiphytum hintoniorum | L.C.Higgins & B.L.Turner | Boraginaceae | 5 |
| Ardisia pellucida | Oerst. | Primulaceae | 5 |
| Aristida havardii | Vasey | Poaceae | 5 |
| Aristida schiedeana | Trin. & Rupr. | Poaceae | 5 |
| Aristolochia monticola | Brandegee | Aristolochiaceae | 5 |
| Aristolochia nana | S.Watson | Aristolochiaceae | 5 |
| Arpophyllum spicatum | Lex. | Orchidaceae | 5 |
| Arracacia atropurpurea | Benth. & Hook.f. ex Hemsl. | Apiaceae | 5 |
| Asemeia violacea | (Aubl.) J.F.B.Pastore & J.R.Abbott | Polygalaceae | 5 |
| Asplenium sessilifolium | Desv. | Aspleniaceae | 5 |
| Astragalus hypoleucus | S.Schauer | Fabaceae | 5 |
| Aureolaria greggii | (S.Watson) Pennell | Orobanchaceae | 5 |
| Baccharis lancifolia | Less. | Asteraceae | 5 |
| Bauhinia chapulhuacania | Wunderlin | Fabaceae | 5 |
| Bidens angustissima | Kunth | Asteraceae | 5 |
| Bidens riparia | Kunth | Asteraceae | 5 |
| Blechnum polypodioides | Raddi | Blechnaceae | 5 |
| Bocconia integrifolia | Bonpl. | Papaveraceae | 5 |
| Bothriochloa springfieldii | (Gould) Parodi | Poaceae | 5 |
| Brickellia spinulosa | (A.Gray) A.Gray | Asteraceae | 5 |
| Buddleja parviflora | Kunth | Scrophulariaceae | 5 |
| Buddleja perfoliata | Kunth | Scrophulariaceae | 5 |
| Bulbostylis tenuifolia | (Rudge) J.F.Macbr. | Cyperaceae | 5 |
| Bunchosia biocellata | Schltdl. | Malpighiaceae | 5 |
| Bursera laxiflora | S.Watson | Burseraceae | 5 |
| Cabomba palaeformis | Fassett | Cabombaceae | 5 |
| Calochortus marcellae | G.L.Nesom | Liliaceae | 5 |
| Canavalia ensiformis | (L.) DC. | Fabaceae | 5 |
| Carphochaete wislizeni | A.Gray | Asteraceae | 5 |
| Casearia nitida | (L.) Jacq. | Salicaceae | 5 |
| Cassipourea elliptica | (Sw.) Poir. | Rhizophoraceae | 5 |
| Castilleja rigida | Eastw. | Orobanchaceae | 5 |
| Cercocarpus pringlei | (C.K.Schneid.) Rydb. | Rosaceae | 5 |
| Cerdia virescens | Moc. & Sessé | Caryophyllaceae | 5 |
| Chenopodium neomexicanum | Standl. | Chenopodiaceae | 5 |
| Choisya palmeri | Standl. | Rutaceae | 5 |
| Chrysactinia pinnata | S.Watson | Asteraceae | 5 |
| Cladocolea inconspicua | (Benth.) Kuijt | Loranthaceae | 5 |
| Cleome gigantea | L. | Cleomaceae | 5 |
| Clibadium arboreum | Donn.Sm. | Asteraceae | 5 |
| Cnidoscolus rotundifolius | (Müll.Arg.) McVaugh | Euphorbiaceae | 5 |
| Coccoloba barbadensis | Jacq. | Polygonaceae | 5 |
| Colubrina elliptica | (Sw.) Briz. & W.L.Stern | Rhamnaceae | 5 |
| Commelina rufipes | Seub. | Commelinaceae | 5 |
| Commelina scabra | Benth. | Commelinaceae | 5 |
| Coryphantha jalpanensis | Buchenau | Cactaceae | 5 |
| Crotalaria maypurensis | Kunth | Fabaceae | 5 |
| Croton alamosanus | Rose | Euphorbiaceae | 5 |
| Croton xalapensis | Kunth | Euphorbiaceae | 5 |
| Crusea wrightii | A.Gray | Rubiaceae | 5 |
| Cuphea calcarata | Benth. | Lythraceae | 5 |
| Cuscuta chinensis | Lam. | Convolvulaceae | 5 |
| Cyclanthera integrifoliola | Cogn. | Cucurbitaceae | 5 |
| Cyperus mutisii | (Kunth) Andersson | Cyperaceae | 5 |
| Cyperus reflexus | Vahl | Cyperaceae | 5 |
| Dalea tomentosa | (Cav.) Willd. | Fabaceae | 5 |
| Deiregyne falcata | (L.O.Williams) Garay | Orchidaceae | 5 |
| Dianthera candelariae | (Oerst.) Hemsl. | Acanthaceae | 5 |
| Dichaetophora campestris | A.Gray | Asteraceae | 5 |
| Digitaria pubiflora | (Vasey) Wipff | Poaceae | 5 |
| Dioscorea carpomaculata | O.Téllez & B.G.Schub. | Dioscoreaceae | 5 |
| Drypetes gentryi | Monach. | Putranjivaceae | 5 |
| Echeveria schaffneri | (S.Watson) Rose | Crassulaceae | 5 |
| Echinocereus rigidissimus | (Engelm.) Rose | Cactaceae | 5 |
| Echinopepon racemosus | (Steud.) C.Jeffrey | Cucurbitaceae | 5 |
| Eleocharis flavescens | (Poir.) Urb. | Cyperaceae | 5 |
| Elymus arizonicus | (Scribn. & J.G.Sm.) Gould | Poaceae | 5 |
| Epiphyllum hookeri | Haw. | Cactaceae | 5 |
| Epithelantha cryptica | D.Donati & Zanov. | Cactaceae | 5 |
| Eriogonum atrorubens | Engelm. | Polygonaceae | 5 |
| Eugenia rhombea | (O.Berg) Krug & Urb. | Myrtaceae | 5 |
| Euphorbia bilobata | Engelm. | Euphorbiaceae | 5 |
| Festuca ligulata | Swallen | Poaceae | 5 |
| Flaveria chlorifolia | A.Gray | Asteraceae | 5 |
| Frangula mcvaughii | (L.A.Johnst. & M.C.Johnst.) A.Pool | Rhamnaceae | 5 |
| Funkiella hyemalis | (A.Rich. & Galeotti) Schltr. | Orchidaceae | 5 |
| Galeoglossum tubulosum | (Lindl.) Salazar & Soto Arenas | Orchidaceae | 5 |
| Govenia lagenophora | Lindl. | Orchidaceae | 5 |
| Grusonia densispina | (Ralston & Hilsenb.) Pinkava | Cactaceae | 5 |
| Guarea glabra | Vahl | Meliaceae | 5 |
| Gutierrezia wrightii | A.Gray | Asteraceae | 5 |
| Hechtia perotensis | I.Ramírez & Mart.-Correa | Bromeliaceae | 5 |
| Heteranthera mexicana | S.Watson | Pontederiaceae | 5 |
| Hymenocallis concinna | Baker | Amaryllidaceae | 5 |
| Jefea lantanifolia | (S.Schauer) Strother | Asteraceae | 5 |
| Klaprothia fasciculata | (C.Presl) Poston | Loasaceae | 5 |
| Lepidaploa tortuosa | (L.) H.Rob. | Asteraceae | 5 |
| Lobelia mcvaughii | T.J.Ayers | Campanulaceae | 5 |
| Lonchitis hirsuta | L. | Lonchitidaceae | 5 |
| Lycaste consobrina | Rchb.f. | Orchidaceae | 5 |
| Malvastrum bicuspidatum | (S.Watson) Rose | Malvaceae | 5 |
| Manihot rhomboidea | Müll.Arg. | Euphorbiaceae | 5 |
| Marina scopa | Barneby | Fabaceae | 5 |
| Melampodium microcephalum | Less. | Asteraceae | 5 |
| Mimosa luisana | Brandegee | Fabaceae | 5 |
| Mimosa monancistra | Benth. | Fabaceae | 5 |
| Mimosa rupertiana | B.L.Turner | Fabaceae | 5 |
| Mostacillastrum purpusii | (Brandegee) Al-Shehbaz | Brassicaceae | 5 |
| Muhlenbergia dubia | E.Fourn. | Poaceae | 5 |
| Muhlenbergia stricta | (J.Presl) Kunth | Poaceae | 5 |
| Nama coulteri | A.Gray | Namaceae | 5 |
| Nama torynophylla | Greenm. | Namaceae | 5 |
| Nectandra mollis | (Kunth) Nees | Lauraceae | 5 |
| Nolina durangensis | Trel. | Asparagaceae | 5 |
| Notholaena grayi | Davenp. | Pteridaceae | 5 |
| Notholaena neglecta | Maxon | Pteridaceae | 5 |
| Oenothera hispida | (Benth.) W.L.Wagner, Hoch & Zarucchi | Onagraceae | 5 |
| Packera zimapanica | (Hemsl.) C.C.Freeman & T.M.Barkley | Asteraceae | 5 |
| Palicourea domingensis | (Jacq.) DC. | Rubiaceae | 5 |
| Parthenice mollis | A.Gray | Asteraceae | 5 |
| Pavonia uniflora | (Sessé & Moc.) Fryxell | Malvaceae | 5 |
| Paysonia lasiocarpa | (Hook. ex A.Gray) O'Kane & Al-Shehbaz | Brassicaceae | 5 |
| Penstemon stenophyllus | A.Gray | Plantaginaceae | 5 |
| Peperomia berlandieri | Miq. | Piperaceae | 5 |
| Peperomia liebmannii | C.DC. | Piperaceae | 5 |
| Peperomia monticola | Miq. | Piperaceae | 5 |
| Pericallis aurita | (L'Hér.) B.Nord. | Asteraceae | 5 |
| Phanerostylis hintoniorum | (B.L.Turner) R.M.King & H.Rob. | Asteraceae | 5 |
| Phyllanthus elsiae | Urb. | Phyllanthaceae | 5 |
| Picradeniopsis pringlei | (Greenm.) B.G.Baldwin | Asteraceae | 5 |
| Pilea pubescens | Liebm. | Urticaceae | 5 |
| Pilosocereus alensis | (F.A.C.Weber) Byles & G.D.Rowley | Cactaceae | 5 |
| Pinguicula lilacina | Schltdl. & Cham. | Lentibulariaceae | 5 |
| Pinguicula macrophylla | Kunth | Lentibulariaceae | 5 |
| Piptochaetium brevicalyx | (E.Fourn.) Ricker ex Hitchc. | Poaceae | 5 |
| Plectocephalus rothrockii | (Greenm.) D.J.N.Hind | Asteraceae | 5 |
| Pleopeltis furfuracea | (Schltdl. & Cham.) A.R.Sm. & Tejero | Polypodiaceae | 5 |
| Pleopeltis thyssanolepis | (A.Braun ex Klotzsch) E.G.Andrews & Windham | Polypodiaceae | 5 |
| Pleurothallis quadrifida | (Lex.) Lindl. | Orchidaceae | 5 |
| Pseudabutilon umbellatum | (L.) Fryxell | Malvaceae | 5 |
| Pseudoclappia arenaria | Rydb. | Asteraceae | 5 |
| Pseudognaphalium inornatum | (DC.) Anderb. | Asteraceae | 5 |
| Psilactis brevilingulata | Sch.Bip. ex Hemsl. | Asteraceae | 5 |
| Randia tetracantha | (Cav.) DC. | Rubiaceae | 5 |
| Ranunculus flagelliformis | Sm. | Ranunculaceae | 5 |
| Rourea glabra | Kunth | Connaraceae | 5 |
| Ruehssia edulis | (S.Watson) L.O.Alvarado | Apocynaceae | 5 |
| Ruellia costaricensis | (Oerst.) E.A.Tripp & McDade | Acanthaceae | 5 |
| Ruellia hirsutoglandulosa | (Oerst.) Hemsl. | Acanthaceae | 5 |
| Sabal uresana | Trel. | Arecaceae | 5 |
| Sabatia arenicola | Greenm. | Gentianaceae | 5 |
| Sabdariffa uncinella | (Moc. & Sessé ex DC.) M.M.Hanes & R.L.Barrett | Malvaceae | 5 |
| Salix paradoxa | Kunth | Salicaceae | 5 |
| Salvia macellaria | Epling | Lamiaceae | 5 |
| Salvia podadena | Briq. | Lamiaceae | 5 |
| Scutellaria hispidula | B.L.Rob. | Lamiaceae | 5 |
| Sedum gypsophilum | B.L.Turner | Crassulaceae | 5 |
| Sedum havardii | Rose | Crassulaceae | 5 |
| Sedum hemsleyanum | Rose | Crassulaceae | 5 |
| Sedum rhodocarpum | Rose | Crassulaceae | 5 |
| Selaginella ribae | Valdespino | Selaginellaceae | 5 |
| Seymeria scabra | A.Gray | Orobanchaceae | 5 |
| Sida glabra | Mill. | Malvaceae | 5 |
| Sideroxylon cartilagineum | (Cronquist) T.D.Penn. | Sapotaceae | 5 |
| Sideroxylon occidentale | (Hemsl.) T.D.Penn. | Sapotaceae | 5 |
| Silene thurberi | S.Watson | Caryophyllaceae | 5 |
| Solanum lanceifolium | Jacq. | Solanaceae | 5 |
| Solanum myriacanthum | Dunal | Solanaceae | 5 |
| Solanum pinnatisectum | Dunal | Solanaceae | 5 |
| Solanum pruinosum | Dunal | Solanaceae | 5 |
| Spermacoce suaveolens | (G.Mey.) Kuntze | Rubiaceae | 5 |
| Stanhopea tigrina | Bateman ex Lindl. | Orchidaceae | 5 |
| Stevia micrantha | Lag. | Asteraceae | 5 |
| Suaeda conferta | (Small) I.M.Johnst. | Chenopodiaceae | 5 |
| Symphoricarpos microphyllus | (Humb. & Bonpl. ex Schult.) Kunth | Caprifoliaceae | 5 |
| Tamonea euphrasiifolia | B.L.Rob. | Verbenaceae | 5 |
| Taxus globosa | Schltdl. | Taxaceae | 5 |
| Ternstroemia lineata | DC. | Pentaphylacaceae | 5 |
| Tillandsia gymnobotrya | Baker | Bromeliaceae | 5 |
| Tillandsia inopinata | Espejo, López-Ferr. & W.Till | Bromeliaceae | 5 |
| Tillandsia polystachia | (L.) L. | Bromeliaceae | 5 |
| Tinantia macrophylla | S.Watson | Commelinaceae | 5 |
| Tradescantia nuevoleonensis | Matuda | Commelinaceae | 5 |
| Tradescantia sillamontana | Matuda | Commelinaceae | 5 |
| Trichocentrum cosymbephorum | (C.Morren) R.Jiménez & Carnevali | Orchidaceae | 5 |
| Trixis michuacana | Lex. | Asteraceae | 5 |
| Vailia anomala | (Brandegee) W.D.Stevens | Apocynaceae | 5 |
| Verbena cloverae | Moldenke | Verbenaceae | 5 |
| Verbesina lottiana | B.L.Turner & J.L.Olsen | Asteraceae | 5 |
| Verbesina olsenii | B.L.Turner | Asteraceae | 5 |
| Vernonia arborescens | (L.) Sw. | Asteraceae | 5 |
| Villadia misera | (Lindl.) R.T.Clausen | Crassulaceae | 5 |
| Viola grahamii | Benth. | Violaceae | 5 |
| Viola hookeriana | Kunth | Violaceae | 5 |
| Ximenia parviflora | Benth. | Olacaceae | 5 |
| Zephyranthes traubii | (Hayward) Moldenke | Amaryllidaceae | 5 |
| Acleisanthes parvifolia | (Torr.) R.A.Levin | Nyctaginaceae | 4 |
| Acourtia tomentosa | (Brandegee) Reveal & R.M.King | Asteraceae | 4 |
| Adenophyllum anomalum | (M.L.Canby & Rose) Strother | Asteraceae | 4 |
| Adenophyllum porophyllum | (Cav.) Hemsl. | Asteraceae | 4 |
| Agave difformis | A.Berger | Asparagaceae | 4 |
| Agave filifera | Salm-Dyck | Asparagaceae | 4 |
| Agave palustris | (Rose) Thiede & Eggli | Asparagaceae | 4 |
| Agave planifolia | S.Watson | Asparagaceae | 4 |
| Agave platyphylla | (Rose) Thiede & Eggli | Asparagaceae | 4 |
| Agave sileri | (Verh.-Will.) Thiede & Eggli | Asparagaceae | 4 |
| Agave weberi | J.F.Cels ex J.Poiss. | Asparagaceae | 4 |
| Anisacanthus pumilus | (F.Dietr.) Nees | Acanthaceae | 4 |
| Antigonon flavescens | S.Watson | Polygonaceae | 4 |
| Archibaccharis schiedeana | (Benth.) J.D.Jacks. | Asteraceae | 4 |
| Ardisia paschalis | Donn.Sm. | Primulaceae | 4 |
| Aristolochia durangensis | Pfeifer | Aristolochiaceae | 4 |
| Aristolochia secunda | Pfeifer | Aristolochiaceae | 4 |
| Arracacia nelsonii | J.M.Coult. & Rose | Apiaceae | 4 |
| Arracacia schneideri | Mathias & Constance | Apiaceae | 4 |
| Arthrostemma alatum | Triana | Melastomataceae | 4 |
| Asclepias circinalis | (Decne.) Woodson | Apocynaceae | 4 |
| Asclepias gordaensis | L.O.Alvarado & S.Islas | Apocynaceae | 4 |
| Asclepias mirifica | Woodson | Apocynaceae | 4 |
| Astragalus goldmanii | M.E.Jones | Fabaceae | 4 |
| Athyrium dombeyi | Desv. | Athyriaceae | 4 |
| Atriplex suckleyi | (Torr.) Rydb. | Chenopodiaceae | 4 |
| Berberis gracilis | Hartw. ex Benth. | Berberidaceae | 4 |
| Bignonia potosina | (K.Schum. & Loes.) L.G.Lohmann | Bignoniaceae | 4 |
| Bouteloua simplex | Lag. | Poaceae | 4 |
| Bouvardia multiflora | (Cav.) Schult. & Schult.f. | Rubiaceae | 4 |
| Brickellia lemmonii | A.Gray | Asteraceae | 4 |
| Brickellia scoparia | A.Gray | Asteraceae | 4 |
| Brickellia venosa | B.L.Rob. | Asteraceae | 4 |
| Bursera instabilis | McVaugh & Rzed. | Burseraceae | 4 |
| Calliandra tergemina | (L.) Benth. | Fabaceae | 4 |
| Canavalia hirsutissima | J.D.Sauer | Fabaceae | 4 |
| Castilleja hirsuta | M.Martens & Galeotti | Orobanchaceae | 4 |
| Castilleja rhizomata | N.H.Holmgren | Orobanchaceae | 4 |
| Celosia virgata | Jacq. | Amaranthaceae | 4 |
| Ceratozamia kuesteriana | Regel | Zamiaceae | 4 |
| Ceratozamia latifolia | Miq. | Zamiaceae | 4 |
| Chaetogastra longisepala | (Cogn.) P.J.F.Guim. & Michelang. | Melastomataceae | 4 |
| Chaetopappa parryi | A.Gray | Asteraceae | 4 |
| Chamaecrista diphylla | (L.) Greene | Fabaceae | 4 |
| Chamaecrista glandulosa | (L.) Greene | Fabaceae | 4 |
| Chamaedorea radicalis | Mart. | Arecaceae | 4 |
| Chaptalia lyratifolia | Burkart | Asteraceae | 4 |
| Chaptalia runcinata | Kunth | Asteraceae | 4 |
| Chthamalia atrostellata | (Rintz) Morillo | Apocynaceae | 4 |
| Chthamalia chihuahuensis | (A.Gray) Morillo | Apocynaceae | 4 |
| Cionosicys macranthus | (Pittier) C.Jeffrey | Cucurbitaceae | 4 |
| Cirsium acrolepis | (Petr.) G.B.Ownbey | Asteraceae | 4 |
| Cissus cacuminis | Standl. | Vitaceae | 4 |
| Citharexylum lycioides | D.Don | Verbenaceae | 4 |
| Citharexylum mocinoi | D.Don | Verbenaceae | 4 |
| Clematis acapulcensis | Hook. & Arn. | Ranunculaceae | 4 |
| Clitoria mexicana | Link | Fabaceae | 4 |
| Cochlospermum palmatifidum | (DC.) Byng & Christenh. | Bixaceae | 4 |
| Corallorhiza bulbosa | A.Rich. & Galeotti | Orchidaceae | 4 |
| Coryphantha elephantidens | (Lem.) Lem. | Cactaceae | 4 |
| Coryphantha glanduligera | (Otto & A.Dietr.) Lem. | Cactaceae | 4 |
| Coryphantha gracilis | Bremer & A.B.Lau | Cactaceae | 4 |
| Cosmos atrosanguineus | (Hook.) Voss | Asteraceae | 4 |
| Cosmos linearifolius | (Sch.Bip.) Hemsl. | Asteraceae | 4 |
| Crataegus baroussana | Eggl. | Rosaceae | 4 |
| Crataegus greggiana | Eggl. | Rosaceae | 4 |
| Crataegus rosei | Eggl. | Rosaceae | 4 |
| Critonia daleoides | DC. | Asteraceae | 4 |
| Croton axillaris | Müll.Arg. | Euphorbiaceae | 4 |
| Croton sancti-lazari | Croizat | Euphorbiaceae | 4 |
| Croton watsonii | Standl. | Euphorbiaceae | 4 |
| Cuphea paucipetala | S.A.Graham | Lythraceae | 4 |
| Cynanchum ligulatum | (Benth.) Woodson | Apocynaceae | 4 |
| Cyperus dipsaceus | Liebm. | Cyperaceae | 4 |
| Dahlia tubulata | P.D.Sørensen | Asteraceae | 4 |
| Dalbergia brownei | (Jacq.) Schinz | Fabaceae | 4 |
| Dalbergia glabra | (Mill.) Standl. | Fabaceae | 4 |
| Deiregyne tenorioi | Soto Arenas & Salazar | Orchidaceae | 4 |
| Desmodium distortum | (Aubl.) J.F.Macbr. | Fabaceae | 4 |
| Diphysa occidentalis | Rose | Fabaceae | 4 |
| Diplazium striatastrum | Lellinger | Athyriaceae | 4 |
| Drymaria anomala | S.Watson | Caryophyllaceae | 4 |
| Drymaria arenarioides | Humb. & Bonpl. ex Schult. | Caryophyllaceae | 4 |
| Dyscritogyne dryophila | (B.L.Rob.) R.M.King & H.Rob. | Asteraceae | 4 |
| Echeandia falcata | Cruden | Asparagaceae | 4 |
| Echeveria chihuahuaensis | Poelln. | Crassulaceae | 4 |
| Echeveria lutea | Rose | Crassulaceae | 4 |
| Echeveria pulidonis | E.Walther | Crassulaceae | 4 |
| Echeveria unguiculata | Kimnach | Crassulaceae | 4 |
| Encyclia candollei | (Lindl.) Schltr. | Orchidaceae | 4 |
| Erigeron canus | A.Gray | Asteraceae | 4 |
| Erythranthe pallens | (Greene) G.L.Nesom | Phrymaceae | 4 |
| Erythrina leptorhiza | Moc. & Sessé ex DC. | Fabaceae | 4 |
| Euphorbia furcillata | Kunth | Euphorbiaceae | 4 |
| Euphorbia ocymoidea | L. | Euphorbiaceae | 4 |
| Euphorbia spurca | (M.C.Johnst.) A.M.Powell | Euphorbiaceae | 4 |
| Fendlera linearis | Rehder | Hydrangeaceae | 4 |
| Ferocactus alamosanus | (Britton & Rose) Britton & Rose | Cactaceae | 4 |
| Ficus velutina | Humb. & Bonpl. ex Willd. | Moraceae | 4 |
| Gaga marginata | (Kunth) Fay W.Li & Windham | Pteridaceae | 4 |
| Garcia nutans | Rohr | Euphorbiaceae | 4 |
| Gaya minutiflora | Rose | Malvaceae | 4 |
| Gentianella canosoi | G.L.Nesom & B.L.Turner | Gentianaceae | 4 |
| Geohintonia mexicana | Glass & W.A.Fitz Maur. | Cactaceae | 4 |
| Gibasis pulchella | (Kunth) Raf. | Commelinaceae | 4 |
| Giliastrum ludens | (Shinners) J.M.Porter | Polemoniaceae | 4 |
| Gonolobus fraternus | Schltdl. | Apocynaceae | 4 |
| Graptopetalum bartramii | Rose | Crassulaceae | 4 |
| Grona adscendens | (Sw.) H.Ohashi & K.Ohashi | Fabaceae | 4 |
| Guardiola mexicana | Bonpl. | Asteraceae | 4 |
| Habenaria castroi | R.González & Cuevas-Figueroa | Orchidaceae | 4 |
| Habenaria strictissima | Rchb.f. | Orchidaceae | 4 |
| Helianthella mexicana | A.Gray | Asteraceae | 4 |
| Heliotropium glabriusculum | A.Gray | Heliotropiaceae | 4 |
| Heliotropium transalpinum | Vell. | Heliotropiaceae | 4 |
| Hemichaena coulteri | (A.Gray) Thieret | Phrymaceae | 4 |
| Heteranthera rotundifolia | (Kunth) Griseb. | Pontederiaceae | 4 |
| Hieracium schultzii | Fr. | Asteraceae | 4 |
| Hoffmannseggia drummondii | Torr. & A.Gray | Fabaceae | 4 |
| Hofmeisteria urenifolia | Walp. | Asteraceae | 4 |
| Ilex discolor | Hemsl. | Aquifoliaceae | 4 |
| Ipomoea bombycina | (Choisy) Benth. & Hook.f. ex Hemsl. | Convolvulaceae | 4 |
| Ipomopsis pringlei | (A.Gray) Henrickson | Polemoniaceae | 4 |
| Iresine arbuscula | Uline & W.L.Bray | Amaranthaceae | 4 |
| Jarilla heterophylla | (Cerv. ex La Llave) Rusby | Caricaceae | 4 |
| Juniperus zanonii | R.P.Adams | Cupressaceae | 4 |
| Lasianthaea ceanothifolia | (Willd.) K.M.Becker | Asteraceae | 4 |
| Lepidium ramosissimum | A.Nelson | Brassicaceae | 4 |
| Leucophyllum virescens | I.M.Johnst. | Scrophulariaceae | 4 |
| Lobelia ehrenbergii | Vatke | Campanulaceae | 4 |
| Lucuma campechiana | Kunth | Sapotaceae | 4 |
| Lysiloma watsonii | Rose | Fabaceae | 4 |
| Lythrum gracile | Benth. | Lythraceae | 4 |
| Mabrya rosei | (Munz) Elisens | Plantaginaceae | 4 |
| Malaxis rosei | Ames | Orchidaceae | 4 |
| Malvastrum corchorifolium | (Desr.) Britton ex Small | Malvaceae | 4 |
| Mammillaria hahniana | Werderm. | Cactaceae | 4 |
| Mammillaria rhodantha | Link & Otto | Cactaceae | 4 |
| Menodora coulteri | A.Gray | Oleaceae | 4 |
| Menodora helianthemoides | Bonpl. | Oleaceae | 4 |
| Miconia chrysoneura | Triana | Melastomataceae | 4 |
| Mimosa lacerata | Rose | Fabaceae | 4 |
| Mirabilis sanguinea | Heimerl | Nyctaginaceae | 4 |
| Mostacillastrum longipes | (Rollins) Al-Shehbaz | Brassicaceae | 4 |
| Muhlenbergia cenchroides | (Humb. & Bonpl. ex Willd.) P.M.Peterson | Poaceae | 4 |
| Muhlenbergia macroura | (Kunth) Hitchc. | Poaceae | 4 |
| Muhlenbergia mutica | (Rupr. ex Galeotti) Hitchc. | Poaceae | 4 |
| Muhlenbergia ramulosa | (Kunth) Swallen | Poaceae | 4 |
| Muhlenbergia straminea | Hitchc. | Poaceae | 4 |
| Myriopteris aemula | (Maxon) Grusz & Windham | Pteridaceae | 4 |
| Myriopteris pringlei | (Davenp.) Grusz & Windham | Pteridaceae | 4 |
| Myrmecophila tibicinis | (Bateman ex Lindl.) Rolfe | Orchidaceae | 4 |
| Myrsine penduliflora | A.DC. | Primulaceae | 4 |
| Nectandra hihua | (Ruiz & Pav.) Rohwer | Lauraceae | 4 |
| Nymphaea amazonum | Mart. & Zucc. | Nymphaeaceae | 4 |
| Opuntia scheeri | F.A.C.Weber | Cactaceae | 4 |
| Opuntia velutina | F.A.C.Weber | Cactaceae | 4 |
| Orthrosanthus exsertus | (R.C.Foster) Ravenna | Iridaceae | 4 |
| Otopappus acuminatus | S.Watson | Asteraceae | 4 |
| Packera candidissima | (Greene) W.A.Weber & Á.Löve | Asteraceae | 4 |
| Packera millelobata | (Rydb.) W.A.Weber & Á.Löve | Asteraceae | 4 |
| Parablechnum schiedeanum | (Schltdl. ex C.Presl) Gasper & Salino | Blechnaceae | 4 |
| Pecluma struthionis | (L.) Boudrie, Cremers & Viane | Polypodiaceae | 4 |
| Penstemon hartwegii | Benth. | Plantaginaceae | 4 |
| Peperomia angustata | Kunth | Piperaceae | 4 |
| Peperomia claytonioides | Kunth | Piperaceae | 4 |
| Persea liebmannii | Mez | Lauraceae | 4 |
| Phoradendron lanceolatum | Engelm. ex A.Gray | Santalaceae | 4 |
| Phyllostylon rhamnoides | (J.Poiss.) Taub. | Ulmaceae | 4 |
| Pinguicula esseriana | B.Kirchn. | Lentibulariaceae | 4 |
| Pinguicula robertiana | Zamudio & Hern.Rend. | Lentibulariaceae | 4 |
| Pitcairnia karwinskyana | Schult. & Schult.f. | Bromeliaceae | 4 |
| Polyphlebium capillaceum | (L.) Ebihara & Dubuisson | Hymenophyllaceae | 4 |
| Potentilla leonina | Standl. | Rosaceae | 4 |
| Potentilla rubra | Willd. ex D.F.K.Schltdl. | Rosaceae | 4 |
| Prunus zinggii | Standl. | Rosaceae | 4 |
| Psacalium eriocarpum | S.F.Blake | Asteraceae | 4 |
| Quercus glabrescens | Benth. | Fagaceae | 4 |
| Quercus invaginata | Trel. | Fagaceae | 4 |
| Quercus mexicana | Bonpl. | Fagaceae | 4 |
| Randia pringlei | A.Gray | Rubiaceae | 4 |
| Rotala mexicana | Schltdl. & Cham. | Lythraceae | 4 |
| Rubus eriocarpus | Liebm. | Rosaceae | 4 |
| Ruehssia pringlei | (S.Watson) L.O.Alvarado | Apocynaceae | 4 |
| Ruehssia zimapanica | (Hemsl.) L.O.Alvarado | Apocynaceae | 4 |
| Russelia tenuis | Lundell | Plantaginaceae | 4 |
| Salvia blepharophylla | Brandegee ex Epling | Lamiaceae | 4 |
| Salvia compsostachys | Epling | Lamiaceae | 4 |
| Salvinia auriculata | Aubl. | Salviniaceae | 4 |
| Savia sessiliflora | (Sw.) Willd. | Phyllanthaceae | 4 |
| Sceptridium schaffneri | (Underw.) Lyon | Ophioglossaceae | 4 |
| Schiedeella transversalis | (A.Rich. & Galeotti) Schltr. | Orchidaceae | 4 |
| Schizachyrium condensatum | (Kunth) Nees | Poaceae | 4 |
| Scutellaria havanensis | Jacq. | Lamiaceae | 4 |
| Sedum bourgaei | Hemsl. | Crassulaceae | 4 |
| Sedum corynephyllum | Fröd. | Crassulaceae | 4 |
| Selaginella stenophylla | A.Braun | Selaginellaceae | 4 |
| Senegalia reniformis | (Benth.) Britton & Rose | Fabaceae | 4 |
| Senna demissa | (Rose) H.S.Irwin & Barneby | Fabaceae | 4 |
| Seymeria deflexa | Eastw. | Orobanchaceae | 4 |
| Sicydium tamnifolium | Cogn. | Cucurbitaceae | 4 |
| Sidastrum paniculatum | (L.) Fryxell | Malvaceae | 4 |
| Sigesbeckia agrestis | Poepp. & Endl. | Asteraceae | 4 |
| Simsia annectens | S.F.Blake | Asteraceae | 4 |
| Sinclairia palmeri | (A.Gray) B.L.Turner | Asteraceae | 4 |
| Sisyrinchium arizonicum | Rothr. | Iridaceae | 4 |
| Spermacoce tenuior | L. | Rubiaceae | 4 |
| Stachys harkerae | J.G.González | Lamiaceae | 4 |
| Staphylea insignis | (Tul.) Byng & Christenh. | Staphyleaceae | 4 |
| Stemodia schottii | Holz. | Plantaginaceae | 4 |
| Stenocereus montanus | (Britton & Rose) Buxb. | Cactaceae | 4 |
| Stevia aschenborniana | Sch.Bip. | Asteraceae | 4 |
| Stevia berlandieri | A.Gray | Asteraceae | 4 |
| Stevia incognita | Grashoff | Asteraceae | 4 |
| Stevia origanoides | Kunth | Asteraceae | 4 |
| Stillingia acutifolia | (Benth.) Benth. & Hook.f. ex Hemsl. | Euphorbiaceae | 4 |
| Streptanthus cutleri | Cory | Brassicaceae | 4 |
| Struthanthus palmeri | Kuijt | Loranthaceae | 4 |
| Stylosanthes humilis | Kunth | Fabaceae | 4 |
| Styrax warscewiczii | Perkins | Styracaceae | 4 |
| Symplocos limoncillo | Bonpl. | Symplocaceae | 4 |
| Tauschia decumbens | J.M.Coult. & Rose | Apiaceae | 4 |
| Thalictrum strigillosum | Hemsl. | Ranunculaceae | 4 |
| Thelocactus buekii | (Klein bis) Britton & Rose | Cactaceae | 4 |
| Trichogalium correllii | (Dempster) Kadereit & Schneew. | Rubiaceae | 4 |
| Trichosalpinx ciliaris | (Lindl.) Luer | Orchidaceae | 4 |
| Tridax tenuifolia | Rose | Asteraceae | 4 |
| Ulmus serotina | Sarg. | Ulmaceae | 4 |
| Valeriana urticifolia | Kunth | Caprifoliaceae | 4 |
| Varilla mexicana | A.Gray | Asteraceae | 4 |
| Verbena delticola | Small ex Perry | Verbenaceae | 4 |
| Vernonia marginata | (Torr.) Raf. | Asteraceae | 4 |
| Viguiera decurrens | (A.Gray) A.Gray | Asteraceae | 4 |
| Viguiera sphaerocephala | Hemsl. | Asteraceae | 4 |
| Villadia patula | Moran & C.H.Uhl | Crassulaceae | 4 |
| Viola guatemalensis | W.Becker | Violaceae | 4 |
| Wissadula periplocifolia | (L.) Thwaites | Malvaceae | 4 |
| Yeatesia platystegia | (Torr.) Hilsenb. | Acanthaceae | 4 |
| Zanthoxylum foliolosum | Donn.Sm. | Rutaceae | 4 |
| Zephyranthes longituba | Flory ex Flagg & G.Lom.Sm. | Amaryllidaceae | 4 |
| Acalypha adenostachya | Müll.Arg. | Euphorbiaceae | 3 |
| Acalypha membranacea | A.Rich. | Euphorbiaceae | 3 |
| Achimenes glabrata | (Zucc.) Fritsch | Gesneriaceae | 3 |
| Acourtia durangensis | B.L.Turner | Asteraceae | 3 |
| Acourtia hidalgoana | B.L.Turner | Asteraceae | 3 |
| Adelia barbinervis | Cham. & Schltdl. | Euphorbiaceae | 3 |
| Adiantum deflectens | Mart. | Pteridaceae | 3 |
| Agastache micrantha | (A.Gray) Wooton & Standl. | Lamiaceae | 3 |
| Agave coetocapnia | (M.Roem.) Govaerts & Thiede | Asparagaceae | 3 |
| Agave wocomahi | Gentry | Asparagaceae | 3 |
| Ageratina campyloclada | (B.L.Rob.) R.M.King & H.Rob. | Asteraceae | 3 |
| Alfaroa mexicana | D.E.Stone | Juglandaceae | 3 |
| Allobriquetia spicata | (Kunth) Bovini | Malvaceae | 3 |
| Alternanthera lanceolata | (Benth.) Schinz | Amaranthaceae | 3 |
| Amaranthus crassipes | Schltdl. | Amaranthaceae | 3 |
| Ammannia grayi | S.A.Graham & Gandhi | Lythraceae | 3 |
| Andropogon tener | (Nees) Kunth | Poaceae | 3 |
| Anoda albiflora | Fryxell | Malvaceae | 3 |
| Anredera ramosa | (Moq.) Eliasson | Basellaceae | 3 |
| Archibaccharis hieracioides | S.F.Blake | Asteraceae | 3 |
| Artemisia franserioides | Greene | Asteraceae | 3 |
| Asanthus solidaginifolius | (A.Gray) R.M.King & H.Rob. | Asteraceae | 3 |
| Asclepias elata | Benth. | Apocynaceae | 3 |
| Asclepias macrotis | Torr. | Apocynaceae | 3 |
| Asclepias scaposa | Vail | Apocynaceae | 3 |
| Aspidotis meifolia | (Eaton) Pic.Serm. | Pteridaceae | 3 |
| Asplundia liebmannii | Harling | Cyclanthaceae | 3 |
| Astragalus waterfallii | Barneby | Fabaceae | 3 |
| Astranthium orthopodum | Larsen | Asteraceae | 3 |
| Aztekium ritteri | (Boed.) Boed. | Cactaceae | 3 |
| Aztekium valdezii | Velazco, M.A.Alvarado & S.Arias | Cactaceae | 3 |
| Baccharis ramiflora | A.Gray | Asteraceae | 3 |
| Barroetea subuligera | A.Gray | Asteraceae | 3 |
| Batesimalva violacea | (Rose) Fryxell | Malvaceae | 3 |
| Bauhinia bartlettii | B.L.Turner | Fabaceae | 3 |
| Bauhinia pringlei | S.Watson | Fabaceae | 3 |
| Bletia adenocarpa | Rchb.f. | Orchidaceae | 3 |
| Bletia ensifolia | L.O.Williams | Orchidaceae | 3 |
| Bletia greenwoodiana | Sosa | Orchidaceae | 3 |
| Bletia macristhmochila | Greenm. | Orchidaceae | 3 |
| Bouteloua erecta | (Vasey & Hack.) Columbus | Poaceae | 3 |
| Bravaisia integerrima | (Spreng.) Standl. | Acanthaceae | 3 |
| Brickellia wislizeni | A.Gray | Asteraceae | 3 |
| Brongniartia lupinoides | (Kunth) Taub. | Fabaceae | 3 |
| Brongniartia parryi | Hemsl. | Fabaceae | 3 |
| Bruceholstia sidifolia | (M.Martens & Galeotti) L.O.Alvarado | Apocynaceae | 3 |
| Bursera roseana | Rzed., Calderón & Medina | Burseraceae | 3 |
| Carminatia recondita | McVaugh | Asteraceae | 3 |
| Castilleja durangensis | G.L.Nesom | Orobanchaceae | 3 |
| Ceanothus ochraceus | Suess. | Rhamnaceae | 3 |
| Cerastium vulcanicum | Schltdl. | Caryophyllaceae | 3 |
| Cercocarpus fothergilloides | Kunth | Rosaceae | 3 |
| Chaetopappa bellioides | (A.Gray) Shinners | Asteraceae | 3 |
| Chenopodium desiccatum | A.Nelson | Chenopodiaceae | 3 |
| Citharexylum racemosum | Sessé & Moc. | Verbenaceae | 3 |
| Clematis grossa | Benth. | Ranunculaceae | 3 |
| Clematis rhodocarpa | Rose | Ranunculaceae | 3 |
| Cleome magnifica | Briq. | Cleomaceae | 3 |
| Cobaea stipularis | Benth. | Polemoniaceae | 3 |
| Cochemiea wrightii | (Engelm. & J.M.Bigelow) Doweld | Cactaceae | 3 |
| Coenoemersa limosa | (Lindl.) R.González & Lizb.Hern. | Orchidaceae | 3 |
| Comarostaphylis mucronata | Klotzsch | Ericaceae | 3 |
| Corchorus hirtus | L. | Malvaceae | 3 |
| Coryphantha pseudonickelsiae | Backeb. | Cactaceae | 3 |
| Cranichis ciliilabia | C.Schweinf. | Orchidaceae | 3 |
| Crotalaria bupleurifolia | Schltdl. & Cham. | Fabaceae | 3 |
| Croton ehrenbergii | Schltdl. | Euphorbiaceae | 3 |
| Croton morifolius | Willd. | Euphorbiaceae | 3 |
| Crusea calocephala | DC. | Rubiaceae | 3 |
| Cuphea calaminthifolia | Schltdl. | Lythraceae | 3 |
| Cuscuta jalapensis | Schltdl. | Convolvulaceae | 3 |
| Cuscuta legitima | Costea & Stefanović | Convolvulaceae | 3 |
| Cuscuta squamata | Engelm. | Convolvulaceae | 3 |
| Cyathea fulva | (M.Martens & Galeotti) Fée | Cyatheaceae | 3 |
| Cylindropuntia anteojoensis | (Pinkava) E.F.Anderson | Cactaceae | 3 |
| Dahlia pugana | Aarón Rodr. & Art.Castro | Asteraceae | 3 |
| Dalea carthagenensis | (Jacq.) J.F.Macbr. | Fabaceae | 3 |
| Dalea laniceps | Barneby | Fabaceae | 3 |
| Dalea lumholtzii | C.B.Rob. & Fernald | Fabaceae | 3 |
| Dalembertia populifolia | Baill. | Euphorbiaceae | 3 |
| Dasylirion longistylum | J.F.Macbr. | Asparagaceae | 3 |
| Dasylirion miquihuanense | Bogler | Asparagaceae | 3 |
| Daucus montanus | Humb. & Bonpl. ex Schult. | Apiaceae | 3 |
| Desmodium helleri | Peyr. | Fabaceae | 3 |
| Desmodium polystachyum | Schltdl. | Fabaceae | 3 |
| Dianthera pectoralis | (Jacq.) J.F.Gmel. | Acanthaceae | 3 |
| Dichanthelium transiens | (Swallen) Sánchez-Ken | Poaceae | 3 |
| Diectomis fastigiata | (Sw.) P.Beauv. | Poaceae | 3 |
| Diospyros palmeri | Eastw. | Ebenaceae | 3 |
| Diplazium urticifolium | Christ | Athyriaceae | 3 |
| Echeandia gentryi | Cruden | Asparagaceae | 3 |
| Echeveria coccinea | (Cav.) DC. | Crassulaceae | 3 |
| Echeveria elegans | Rose | Crassulaceae | 3 |
| Echeveria novogaliciana | J.Reyes, Brachet & O.González | Crassulaceae | 3 |
| Echeveria paniculata | A.Gray | Crassulaceae | 3 |
| Echeveria waltheri | Moran & J.Meyrán | Crassulaceae | 3 |
| Echinocereus longisetus | (Engelm.) Lem. | Cactaceae | 3 |
| Echinocereus papillosus | Linke ex Rümpler | Cactaceae | 3 |
| Echinocereus reichenbachii | (Terscheck ex Walp.) J.N.Haage | Cactaceae | 3 |
| Echinochloa polystachya | (Kunth) Hitchc. | Poaceae | 3 |
| Elaphoglossum sartorii | (Liebm.) Mickel | Dryopteridaceae | 3 |
| Epidendrum polyanthum | Lindl. | Orchidaceae | 3 |
| Erigeron versicolor | (Greenm.) G.L.Nesom | Asteraceae | 3 |
| Eriocoma robusta | (Vasey) Romasch. | Poaceae | 3 |
| Eryngium comosum | F.Delaroche | Apiaceae | 3 |
| Eryngium deppeanum | Cham. & Schltdl. | Apiaceae | 3 |
| Eryngium longifolium | Cav. | Apiaceae | 3 |
| Erythranthe flammea | G.L.Nesom | Phrymaceae | 3 |
| Euphorbia alta | Norton | Euphorbiaceae | 3 |
| Euphorbia guadalajarana | S.Watson | Euphorbiaceae | 3 |
| Euphorbia lancifolia | Schltdl. | Euphorbiaceae | 3 |
| Euphorbia mcvaughiana | M.C.Johnst. | Euphorbiaceae | 3 |
| Euphorbia perennans | (Shinners) Warnock & M.C.Johnst. | Euphorbiaceae | 3 |
| Euphorbia scopulorum | Brandegee | Euphorbiaceae | 3 |
| Euphorbia sphaerorhiza | Benth. | Euphorbiaceae | 3 |
| Euploca humilis | (L.) Feuillet | Heliotropiaceae | 3 |
| Eutetras palmeri | A.Gray | Asteraceae | 3 |
| Eysenhardtia schizocalyx | Pennell | Fabaceae | 3 |
| Flourensia resinosa | S.F.Blake | Asteraceae | 3 |
| Forchhammeria trifoliata | Radlk. ex Millsp. | Resedaceae | 3 |
| Forestiera durangensis | Standl. | Oleaceae | 3 |
| Frankenia gypsophila | I.M.Johnst. | Frankeniaceae | 3 |
| Fraxinus gooddingii | Little | Oleaceae | 3 |
| Galium uncinulatum | DC. | Rubiaceae | 3 |
| Galphimia tuberculata | (Rose) Nied. | Malpighiaceae | 3 |
| Gentianella amarella | (L.) Börner | Gentianaceae | 3 |
| Gentianopsis lanceolata | (Benth.) Iltis | Gentianaceae | 3 |
| Geranium niveum | S.Watson | Geraniaceae | 3 |
| Gibasis venustula | (Kunth) D.R.Hunt | Commelinaceae | 3 |
| Gongylocarpus rubricaulis | Cham. & Schltdl. | Onagraceae | 3 |
| Gonolobus calcaratus | (Woodson) L.O.Alvarado & Velazco | Apocynaceae | 3 |
| Gonolobus chloranthus | Schltdl. | Apocynaceae | 3 |
| Gonolobus niger | (Cav.) Schult. | Apocynaceae | 3 |
| Gouania polygama | (Jacq.) Urb. | Rhamnaceae | 3 |
| Graptopetalum paraguayense | (N.E.Br.) E.Walther | Crassulaceae | 3 |
| Gyminda latifolia | (Sw.) Urb. | Celastraceae | 3 |
| Habenaria filifera | S.Watson | Orchidaceae | 3 |
| Habranthus chichimeca | (T.M.Howard & S.Ogden) Flagg, G.Lom.Sm. & Meerow | Amaryllidaceae | 3 |
| Halenia recurva | (Sm.) C.K.Allen | Gentianaceae | 3 |
| Hampea nutricia | Fryxell | Malvaceae | 3 |
| Helianthella gypsophila | B.L.Turner | Asteraceae | 3 |
| Heliocarpus appendiculatus | Turcz. | Malvaceae | 3 |
| Heteropterys cotinifolia | A.Juss. | Malpighiaceae | 3 |
| Heterotoma lobelioides | Zucc. | Campanulaceae | 3 |
| Hibiscus elegans | Standl. | Malvaceae | 3 |
| Horsfordia rotundifolia | S.Watson | Malvaceae | 3 |
| Hybanthus longipes | (Dowell) Standl. | Violaceae | 3 |
| Hydrangea seemannii | L.Riley | Hydrangeaceae | 3 |
| Hymenocallis acutifolia | (Herb.) Sweet | Amaryllidaceae | 3 |
| Hymenostephium tenue | (A.Gray) E.E.Schill. & Panero | Asteraceae | 3 |
| Ipomoea rupicola | House | Convolvulaceae | 3 |
| Ipomoea tenuiloba | Torr. | Convolvulaceae | 3 |
| Iresine schaffneri | S.Watson | Amaranthaceae | 3 |
| Isochilus bracteatus | (Lex.) Espejo & López-Ferr. | Orchidaceae | 3 |
| Isochilus unilateralis | B.L.Rob. | Orchidaceae | 3 |
| Isocoma hartwegii | Greene | Asteraceae | 3 |
| Justicia hintoniorum | G.L.Nesom | Acanthaceae | 3 |
| Koanophyllon palmeri | (A.Gray) R.M.King & H.Rob. | Asteraceae | 3 |
| Krameria paucifolia | Rose | Krameriaceae | 3 |
| Lagascea rigida | (Cav.) Stuessy | Asteraceae | 3 |
| Lenophyllum acutifolium | Rose | Crassulaceae | 3 |
| Leucaena macrophylla | Benth. | Fabaceae | 3 |
| Leucosyris coulteri | (A.Gray) Pruski & R.L.Hartm. | Asteraceae | 3 |
| Leucosyris parviflora | (A.Gray) Pruski & R.L.Hartm. | Asteraceae | 3 |
| Licaria capitata | (Cham. & Schltdl.) Kosterm. | Lauraceae | 3 |
| Linum mexicanum | Kunth | Linaceae | 3 |
| Lithospermum rosei | (I.M.Johnst.) J.I.Cohen | Boraginaceae | 3 |
| Litsea novoleontis | Bartlett | Lauraceae | 3 |
| Lonchocarpus punctatus | Kunth | Fabaceae | 3 |
| Lopezia semeiandra | Plitmann, P.H.Raven & Breedlove | Onagraceae | 3 |
| Lupinus cacuminis | Standl. | Fabaceae | 3 |
| Lyonia squamulosa | M.Martens & Galeotti | Ericaceae | 3 |
| Mammillaria pilispina | J.A.Purpus | Cactaceae | 3 |
| Mandevilla brachysiphon | (Torr.) Pichon | Apocynaceae | 3 |
| Maranta gibba | Sm. | Marantaceae | 3 |
| Melpomene peruviana | (Desv.) Reider & R.C.Moran | Polypodiaceae | 3 |
| Mesadenus polyanthus | (Rchb.f.) Schltr. | Orchidaceae | 3 |
| Mexicania congesta | (Decne.) L.O.Alvarado & Lozada-Pérez | Apocynaceae | 3 |
| Miconia madrensis | Standl. | Melastomataceae | 3 |
| Mimosa monclovensis | R.Grether & Marc.F.Simon | Fabaceae | 3 |
| Mitracarpus breviflorus | A.Gray | Rubiaceae | 3 |
| Morisonia frondosa | (Jacq.) Christenh. & Byng | Capparaceae | 3 |
| Morkillia mexicana | (Moc. & Sessé ex DC.) Rose & J.H.Painter | Zygophyllaceae | 3 |
| Muhlenbergia flaviseta | Scribn. | Poaceae | 3 |
| Muhlenbergia pauciflora | Buckley | Poaceae | 3 |
| Muhlenbergia repens | (J.Presl) Hitchc. | Poaceae | 3 |
| Myriocarpa cordifolia | Liebm. | Urticaceae | 3 |
| Nama hitchcockii | J.D.Bacon | Namaceae | 3 |
| Nama undulata | Kunth | Namaceae | 3 |
| Nephrolepis undulata | (Afzel. ex Sw.) J.Sm. | Nephrolepidaceae | 3 |
| Notholaena affinis | (Mett.) T.Moore | Pteridaceae | 3 |
| Nymphaea jamesoniana | Planch. | Nymphaeaceae | 3 |
| Oenothera arida | W.L.Wagner & Hoch | Onagraceae | 3 |
| Oenothera havardii | S.Watson | Onagraceae | 3 |
| Oncidium maculatum | (Lindl.) Lindl. | Orchidaceae | 3 |
| Ophioglossum reticulatum | L. | Ophioglossaceae | 3 |
| Orthosia mexicana | (S.Watson) Liede & Meve | Apocynaceae | 3 |
| Otatea nayeeri | Ruiz-Sanchez | Poaceae | 3 |
| Oxalis lunulata | Zucc. | Oxalidaceae | 3 |
| Oxypappus scaber | Benth. | Asteraceae | 3 |
| Pectis imberbis | A.Gray | Asteraceae | 3 |
| Pectis longipes | A.Gray | Asteraceae | 3 |
| Pedicularis gordonii | McVaugh & Koptur | Orobanchaceae | 3 |
| Pelexia adnata | (Sw.) Poit. ex Rich. | Orchidaceae | 3 |
| Peltostigma pteleoides | (Hook.) Walp. | Rutaceae | 3 |
| Persea schiedeana | Nees | Lauraceae | 3 |
| Phanerophlebia auriculata | Underw. | Dryopteridaceae | 3 |
| Phaseolus ritensis | M.E.Jones | Fabaceae | 3 |
| Phemeranthus parvulus | (Rose & Standl.) D.J.Ferguson & T.M.Price | Montiaceae | 3 |
| Phoradendron nervosum | Oliv. | Santalaceae | 3 |
| Phyllanthus acuminatus | Vahl | Phyllanthaceae | 3 |
| Phyllanthus liebmannianus | Müll.Arg. | Phyllanthaceae | 3 |
| Phymosia umbellata | (Cav.) Kearney | Malvaceae | 3 |
| Physalis coztomatl | Dunal | Solanaceae | 3 |
| Physaria argyraea | (A.Gray) O'Kane & Al-Shehbaz | Brassicaceae | 3 |
| Physaria schaffneri | (S.Watson) O'Kane & Al-Shehbaz | Brassicaceae | 3 |
| Pinguicula acuminata | Benth. | Lentibulariaceae | 3 |
| Pinguicula cyclosecta | Casper | Lentibulariaceae | 3 |
| Pitcairnia palmeri | S.Watson | Bromeliaceae | 3 |
| Pleopeltis alansmithii | (R.C.Moran) A.R.Sm. & Tejero | Polypodiaceae | 3 |
| Poa alpigena | Lindm. | Poaceae | 3 |
| Polystemma fuscum | (Decne.) C.Cerv., S.Arias & L.O.Alvarado | Apocynaceae | 3 |
| Polytaenium feei | (W.Schaffn. ex Fée) Maxon | Pteridaceae | 3 |
| Pombalia verbenacea | (Standl. & Steyerm.) H.E.Ballard & Paula-Souza | Violaceae | 3 |
| Prosthechea squalida | (Lex.) Soto Arenas & Salazar | Orchidaceae | 3 |
| Psacalium megaphyllum | Rydb. | Asteraceae | 3 |
| Psacalium radulifolium | (Kunth) H.Rob. & Brettell | Asteraceae | 3 |
| Pseudabutilon scabrum | (C.Presl) R.E.Fr. | Malvaceae | 3 |
| Pseudalcantarea grandis | (Schltdl.) Pinzón & Barfuss | Bromeliaceae | 3 |
| Pseudoeriocoma eminens | (Cav.) Romasch. | Poaceae | 3 |
| Pseudosmodingium virletii | (Baill.) Engl. | Anacardiaceae | 3 |
| Pteridium latiusculum | Hieron. | Dennstaedtiaceae | 3 |
| Pteris pulchra | Schltdl. & Cham. | Pteridaceae | 3 |
| Quercus hintoniorum | Nixon & C.H.Mull. | Fagaceae | 3 |
| Quercus huicholensis | R.A.McCauley | Fagaceae | 3 |
| Quercus tarahumara | Spellenb., J.R.Bacon & Breedlove | Fagaceae | 3 |
| Rhipidocladum racemiflorum | (Steud.) McClure | Poaceae | 3 |
| Rhus tepetate | Standl. & F.A.Barkley | Anacardiaceae | 3 |
| Rhynchosia reticulata | (Sw.) DC. | Fabaceae | 3 |
| Ricoa leptophylla | (DC.) Duno & Torke | Fabaceae | 3 |
| Roupala montana | Aubl. | Proteaceae | 3 |
| Ruehssia coulteri | (Hemsl.) L.O.Alvarado | Apocynaceae | 3 |
| Ruehssia macrophylla | (Humb. & Bonpl. ex Schult.) H.Karst. | Apocynaceae | 3 |
| Ruellia geminiflora | Kunth | Acanthaceae | 3 |
| Salvia candicans | M.Martens & Galeotti | Lamiaceae | 3 |
| Sambucus mexicana | C.Presl ex DC. | Viburnaceae | 3 |
| Scirpoides mexicana | (C.B.Clarke) Goetgh. ex C.S.Reid & J.R.Carter | Cyperaceae | 3 |
| Scleria lithosperma | (L.) Sw. | Cyperaceae | 3 |
| Sedum botterii | Hemsl. | Crassulaceae | 3 |
| Sedum napiferum | Peyr. | Crassulaceae | 3 |
| Selaginella gypsophila | A.R.Sm. & T.Reeves | Selaginellaceae | 3 |
| Selaginella harrisii | Underw. & Hieron. | Selaginellaceae | 3 |
| Senecio stoechadiformis | DC. | Asteraceae | 3 |
| Sericodes greggii | A.Gray | Zygophyllaceae | 3 |
| Setaria tenax | (Rich.) Desv. | Poaceae | 3 |
| Setaria texana | Emery | Poaceae | 3 |
| Sidastrum lodiegense | (Baker) Fryxell | Malvaceae | 3 |
| Sideroxylon palmeri | (Rose) T.D.Penn. | Sapotaceae | 3 |
| Solanum stenophyllidium | Bitter | Solanaceae | 3 |
| Stelis platystylis | (Schltr.) Solano & Soto Arenas | Orchidaceae | 3 |
| Stellaria ovata | Willd. ex D.F.K.Schltdl. | Caryophyllaceae | 3 |
| Stevia pyrolifolia | Schltdl. | Asteraceae | 3 |
| Sticherus underwoodianus | (Maxon) Nakai | Gleicheniaceae | 3 |
| Styrax radians | P.W.Fritsch | Styracaceae | 3 |
| Tamayorkis porphyrea | (Ridl.) Salazar & Soto Arenas | Orchidaceae | 3 |
| Tessiera lithospermoides | DC. | Rubiaceae | 3 |
| Thymophylla aurea | (A.Gray) Greene ex Britton & A.Br. | Asteraceae | 3 |
| Tigridia dugesii | S.Watson | Iridaceae | 3 |
| Tilia mexicana | Schltdl. | Malvaceae | 3 |
| Tillandsia kirchhoffiana | Wittm. | Bromeliaceae | 3 |
| Tiquilia mexicana | (S.Watson) A.T.Richardson | Ehretiaceae | 3 |
| Tournefortia calycina | Benth. | Heliotropiaceae | 3 |
| Trichogalium microphyllum | (A.Gray) Kadereit & Schneew. | Rubiaceae | 3 |
| Vauquelinia californica | (Torr.) Sarg. | Rosaceae | 3 |
| Vauquelinia corymbosa | Corrêa ex Bonpl. | Rosaceae | 3 |
| Verbesina coahuilensis | A.Gray ex S.Watson | Asteraceae | 3 |
| Viola humilis | Kunth | Violaceae | 3 |
| Viola umbraticola | Kunth | Violaceae | 3 |
| Wedelia greenmanii | B.L.Turner | Asteraceae | 3 |
| Wimmeria bartlettii | Lundell | Celastraceae | 3 |
| Wimmeria concolor | Schltdl. & Cham. | Celastraceae | 3 |
| Woodsia cochisensis | Windham | Woodsiaceae | 3 |
| Yucca linearifolia | Clary | Asparagaceae | 3 |
| Zaluzania megacephala | Sch.Bip. | Asteraceae | 3 |
| Zanthoxylum caribaeum | Lam. | Rutaceae | 3 |
| Zephyranthes lindleyana | Herb. | Amaryllidaceae | 3 |
| Zinnia haageana | Regel | Asteraceae | 3 |
Abies concolorwhite fir
Abies guatemalensisGuatemalan Fir
Abies religiosaOyamel Fir
Abies vejariiVejar's Fir
Abildgaardia ovataflatspike sedge
Abronia angustifoliapurple sand verbena
Abronia carneawinged sandpuffs
Abronia fragranssnowball sand verbena
Abutilon abutiloidesshrubby Indian mallow
Abutilon fruticosumTexas Indian mallow
Abutilon hypoleucumwhiteleaf Indian mallow
Abutilon incanumHoary Indian-mallow
Abutilon malacumyellow Indian mallow
Abutilon mollicomumSonoran Indian mallow
Abutilon palmeriPalmer's Indian mallow
Abutilon parvulumdwarf Indian mallow
Abutilon reventumyellowflower Indian mallow
Abutilon trisulcatumanglestem Indian mallow
Abutilon viscosumviscid mallow
Abutilon wrightiiWright's Indian mallow
Acaciella angustissimaprairie acacia
Acaena elongata
Acalypha alopecuroideafoxtail copperleaf
Acalypha arvensisfield copperleaf
Acalypha californicaCalifornia copperleaf
Acalypha cincta
Acalypha diversifolia
Acalypha leptopoda
Acalypha macrostachya
Acalypha mexicanaMexican copperleaf
Acalypha monostachyaround copperleaf
Acalypha neomexicanaNew Mexico copperleaf
Acalypha persimilispineland threeseed mercury
Acalypha phleoidesshrubby copperleaf
Acalypha poiretiiPoiret's copperleaf
Acalypha radianscardinal's feather
Acanthocereus tetragonusBarbed-wire cactus
Acer glabrumRocky Mountain maple
Acer negundobox elder
Acer saccharumsugar maple
Achimenes antirrhina
Achimenes erecta
Achimenes grandiflora
Achimenes heterophylla
Achimenes skinneri
Achyronychia cooperionyxflower
Acleisanthes anisophyllaobliqueleaf trumpets
Acleisanthes chenopodioidesgoosefoot moonpod
