| Abronia fragrans | Nutt. ex Hook. | Nyctaginaceae | 8 |
| Acalypha persimilis | Müll.Arg. | Euphorbiaceae | 8 |
| Acalypha rhomboidea | Raf. | Euphorbiaceae | 8 |
| Acalypha virginica | L. | Euphorbiaceae | 8 |
| Acer glabrum | Torr. | Sapindaceae | 8 |
| Acer negundo | L. | Sapindaceae | 8 |
| Acer saccharinum | L. | Sapindaceae | 8 |
| Acer saccharum | Marshall | Sapindaceae | 8 |
| Acorus calamus | L. | Acoraceae | 8 |
| Actaea pachypoda | Elliott | Ranunculaceae | 8 |
| Actaea rubra | (Aiton) Willd. | Ranunculaceae | 8 |
| Adiantum pedatum | L. | Pteridaceae | 8 |
| Aesculus glabra | Willd. | Sapindaceae | 8 |
| Agalinis aspera | (Douglas ex Benth.) Britton | Orobanchaceae | 8 |
| Agalinis gattingeri | (Small) Small ex Britton & A.Br. | Orobanchaceae | 8 |
| Agalinis purpurea | (L.) Pennell | Orobanchaceae | 8 |
| Agalinis tenuifolia | (Vahl) Raf. | Orobanchaceae | 8 |
| Agastache foeniculum | (Pursh) Kuntze | Lamiaceae | 8 |
| Agastache nepetoides | (L.) Kuntze | Lamiaceae | 8 |
| Ageratina altissima | (L.) R.M.King & H.Rob. | Asteraceae | 8 |
| Agrimonia gryposepala | Wallr. | Rosaceae | 8 |
| Agrimonia parviflora | Aiton | Rosaceae | 8 |
| Agrimonia pubescens | Wallr. | Rosaceae | 8 |
| Agrostis hyemalis | (Walter) Britton, Sterns & Poggenb. | Poaceae | 8 |
| Agrostis perennans | (Walter) Tuck. | Poaceae | 8 |
| Agrostis scabra | Willd. | Poaceae | 8 |
| Alisma gramineum | Lej. | Alismataceae | 8 |
| Alisma subcordatum | Raf. | Alismataceae | 8 |
| Alisma triviale | Pursh | Alismataceae | 8 |
| Allium canadense | L. | Amaryllidaceae | 8 |
| Allium cernuum | Roth | Amaryllidaceae | 8 |
| Allium drummondii | Regel | Amaryllidaceae | 8 |
| Allium stellatum | Nutt. ex Ker Gawl. | Amaryllidaceae | 8 |
| Allium textile | A.Nelson & J.F.Macbr. | Amaryllidaceae | 8 |
| Alopecurus aequalis | Sobol. | Poaceae | 8 |
| Alopecurus carolinianus | Walter | Poaceae | 8 |
| Amaranthus blitoides | S.Watson | Amaranthaceae | 8 |
| Amaranthus hypochondriacus | L. | Amaranthaceae | 8 |
| Amaranthus tuberculatus | (Moq.) J.D.Sauer | Amaranthaceae | 8 |
| Ambrosia acanthicarpa | Hook. | Asteraceae | 8 |
| Ambrosia artemisiifolia | L. | Asteraceae | 8 |
| Ambrosia grayi | (A.Nelson) Shinners | Asteraceae | 8 |
| Ambrosia psilostachya | DC. | Asteraceae | 8 |
| Ambrosia trifida | L. | Asteraceae | 8 |
| Amelanchier alnifolia | (Nutt.) Nutt. ex M.Roem. | Rosaceae | 8 |
| Amelanchier arborea | (F.Michx.) Fernald | Rosaceae | 8 |
| Amelanchier humilis | Wiegand | Rosaceae | 8 |
| Ammannia auriculata | Willd. | Lythraceae | 8 |
| Ammannia coccinea | Rottb. | Lythraceae | 8 |
| Ammannia robusta | Heer & Regel | Lythraceae | 8 |
| Amorpha canescens | Pursh | Fabaceae | 8 |
| Amorpha nana | Nutt. | Fabaceae | 8 |
| Ampelopsis cordata | Michx. | Vitaceae | 8 |
| Amphicarpaea bracteata | (L.) Fernald | Fabaceae | 8 |
| Amphiscirpus nevadensis | (S.Watson) Oteng-Yeb. | Cyperaceae | 8 |
| Anaphalis margaritacea | (L.) Benth. & Hook.f. | Asteraceae | 8 |
| Andropogon hallii | Hack. | Poaceae | 8 |
| Androsace occidentalis | Pursh | Primulaceae | 8 |
| Anemonastrum canadense | (L.) Mosyakin | Ranunculaceae | 8 |
| Anemone caroliniana | Walter | Ranunculaceae | 8 |
| Anemone cylindrica | A.Gray | Ranunculaceae | 8 |
| Anemone multifida | Poir. | Ranunculaceae | 8 |
| Anemone virginiana | L. | Ranunculaceae | 8 |
| Antennaria dimorpha | Torr. & A.Gray | Asteraceae | 8 |
| Antennaria howellii | Greene | Asteraceae | 8 |
| Antennaria microphylla | Rydb. | Asteraceae | 8 |
| Antennaria neglecta | Greene | Asteraceae | 8 |
| Antennaria parlinii | Fernald | Asteraceae | 8 |
| Antennaria parvifolia | Nutt. | Asteraceae | 8 |
| Anthoxanthum nitens | (Weber) Y.Schouten & Veldkamp | Poaceae | 8 |
| Anticlea elegans | (Pursh) Rydb. | Melanthiaceae | 8 |
| Apios americana | Medik. | Fabaceae | 8 |
| Apocynum androsaemifolium | L. | Apocynaceae | 8 |
| Apocynum cannabinum | L. | Apocynaceae | 8 |
| Aquilegia canadensis | L. | Ranunculaceae | 8 |
| Aralia nudicaulis | L. | Araliaceae | 8 |
| Aralia racemosa | L. | Araliaceae | 8 |
| Argemone polyanthemos | (Fedde) Ownbey | Papaveraceae | 8 |
| Argentina anserina | (L.) Rydb. | Rosaceae | 8 |
| Argyrochosma dealbata | (Pursh) Windham | Pteridaceae | 8 |
| Arisaema dracontium | (L.) Schott | Araceae | 8 |
| Arisaema triphyllum | (L.) Schott | Araceae | 8 |
| Aristida adscensionis | L. | Poaceae | 8 |
| Aristida desmantha | Trin. & Rupr. | Poaceae | 8 |
| Aristida longespica | Poir. | Poaceae | 8 |
| Aristida oligantha | Michx. | Poaceae | 8 |
| Aristida purpurascens | Poir. | Poaceae | 8 |
| Arnoglossum atriplicifolium | (L.) H.Rob. | Asteraceae | 8 |
| Arnoglossum plantagineum | Raf. | Asteraceae | 8 |
| Artemisia campestris | L. | Asteraceae | 8 |
| Artemisia cana | Pursh | Asteraceae | 8 |
| Artemisia dracunculus | L. | Asteraceae | 8 |
| Artemisia filifolia | Torr. | Asteraceae | 8 |
| Artemisia frigida | Willd. | Asteraceae | 8 |
| Artemisia longifolia | Nutt. | Asteraceae | 8 |
| Artemisia ludoviciana | Nutt. | Asteraceae | 8 |
| Artemisia tridentata | Nutt. | Asteraceae | 8 |
| Asarum canadense | L. | Aristolochiaceae | 8 |
| Asclepias amplexicaulis | Sm. | Apocynaceae | 8 |
| Asclepias arenaria | Torr. | Apocynaceae | 8 |
| Asclepias asperula | (Decne.) Woodson | Apocynaceae | 8 |
| Asclepias engelmanniana | Woodson | Apocynaceae | 8 |
| Asclepias incarnata | L. | Apocynaceae | 8 |
| Asclepias latifolia | (Torr.) Raf. | Apocynaceae | 8 |
| Asclepias pumila | (A.Gray) Vail | Apocynaceae | 8 |
| Asclepias purpurascens | L. | Apocynaceae | 8 |
| Asclepias speciosa | Torr. | Apocynaceae | 8 |
| Asclepias stenophylla | A.Gray | Apocynaceae | 8 |
| Asclepias sullivantii | Engelm. ex A.Gray | Apocynaceae | 8 |
| Asclepias syriaca | L. | Apocynaceae | 8 |
| Asclepias tuberosa | L. | Apocynaceae | 8 |
| Asclepias verticillata | L. | Apocynaceae | 8 |
| Asclepias viridiflora | Raf. | Apocynaceae | 8 |
| Asclepias viridis | Walter | Apocynaceae | 8 |
| Asimina triloba | (L.) Dunal | Annonaceae | 8 |
| Asplenium platyneuron | (L.) Britton, Sterns & Poggenb. | Aspleniaceae | 8 |
| Aster subulatus | Michx. | Asteraceae | 8 |
| Astragalus agrestis | Douglas ex G.Don | Fabaceae | 8 |
| Astragalus bisulcatus | (Hook.) A.Gray | Fabaceae | 8 |
| Astragalus bodinii | E.Sheld. | Fabaceae | 8 |
| Astragalus canadensis | L. | Fabaceae | 8 |
| Astragalus ceramicus | E.Sheld. | Fabaceae | 8 |
| Astragalus crassicarpus | Nutt. | Fabaceae | 8 |
| Astragalus drummondii | Douglas ex Hook. | Fabaceae | 8 |
| Astragalus flexuosus | (Hook.) Douglas ex G.Don | Fabaceae | 8 |
| Astragalus gilviflorus | E.Sheld. | Fabaceae | 8 |
| Astragalus gracilis | Nutt. | Fabaceae | 8 |
| Astragalus hyalinus | M.E.Jones | Fabaceae | 8 |
| Astragalus kentrophyta | A.Gray | Fabaceae | 8 |
| Astragalus laxmannii | Jacq. | Fabaceae | 8 |
| Astragalus lotiflorus | Hook. | Fabaceae | 8 |
| Astragalus missouriensis | Nutt. | Fabaceae | 8 |
| Astragalus mollissimus | Torr. | Fabaceae | 8 |
| Astragalus multiflorus | (Pursh) A.Gray | Fabaceae | 8 |
| Astragalus pectinatus | (Hook.) Douglas ex G.Don | Fabaceae | 8 |
| Astragalus plattensis | Nutt. | Fabaceae | 8 |
| Astragalus racemosus | Pursh | Fabaceae | 8 |
| Astragalus sericoleucus | A.Gray | Fabaceae | 8 |
| Astragalus shortianus | Nutt. | Fabaceae | 8 |
| Astragalus spatulatus | E.Sheld. | Fabaceae | 8 |
| Atriplex argentea | Nutt. | Chenopodiaceae | 8 |
| Atriplex canescens | (Pursh) Nutt. | Chenopodiaceae | 8 |
| Azolla caroliniana | Willd. | Salviniaceae | 8 |
| Azolla filiculoides | Lam. | Salviniaceae | 8 |
| Baptisia australis | (L.) R.Br. | Fabaceae | 8 |
| Baptisia lactea | (Raf.) Thieret | Fabaceae | 8 |
| Baptisia leucophaea | Nutt. | Fabaceae | 8 |
| Beckmannia syzigachne | (Steud.) Fernald | Poaceae | 8 |
| Berberis repens | Lindl. | Berberidaceae | 8 |
| Berula erecta | (Huds.) Coville | Apiaceae | 8 |
| Betula occidentalis | Hook. | Betulaceae | 8 |
| Betula papyrifera | Marshall | Betulaceae | 8 |
| Betula pumila | L. | Betulaceae | 8 |
| Bidens bipinnata | L. | Asteraceae | 8 |
| Bidens cernua | L. | Asteraceae | 8 |
| Bidens connata | Muhl. ex Willd. | Asteraceae | 8 |
| Bidens frondosa | L. | Asteraceae | 8 |
| Bidens polylepis | S.F.Blake | Asteraceae | 8 |
| Bidens trichosperma | (Michx.) Britton | Asteraceae | 8 |
| Bidens tripartita | L. | Asteraceae | 8 |
| Bidens vulgata | Greene | Asteraceae | 8 |
| Blephilia hirsuta | (Pursh) Benth. | Lamiaceae | 8 |
| Blitum nuttallianum | Schult. | Chenopodiaceae | 8 |
| Boehmeria cylindrica | (L.) Sw. | Urticaceae | 8 |
| Bolboschoenus fluviatilis | (Torr.) Soják | Cyperaceae | 8 |
| Bolboschoenus maritimus | (L.) Palla | Cyperaceae | 8 |
| Boltonia asteroides | L'Hér. | Asteraceae | 8 |
| Borodinia canadensis | (L.) P.J.Alexander & Windham | Brassicaceae | 8 |
| Borodinia dentata | (Raf.) P.J.Alexander & Windham | Brassicaceae | 8 |
| Bothriochloa torreyana | (Steud.) Scrivanti & Anton | Poaceae | 8 |
| Botrychium campestre | W.H.Wagner & Farrar | Ophioglossaceae | 8 |
| Botrypus virginianus | (L.) Michx. | Ophioglossaceae | 8 |
| Bouteloua curtipendula | (Michx.) Torr. | Poaceae | 8 |
| Bouteloua dactyloides | (Nutt.) Columbus | Poaceae | 8 |
| Bouteloua gracilis | (Kunth) Lag. ex Griffiths | Poaceae | 8 |
| Bouteloua hirsuta | Lag. | Poaceae | 8 |
| Brachyelytrum erectum | (Schreb.) P.Beauv. | Poaceae | 8 |
| Brickellia grandiflora | Nutt. | Asteraceae | 8 |
| Bromus ciliatus | L. | Poaceae | 8 |
| Bromus latiglumis | (Shear) Hitchc. | Poaceae | 8 |
| Bromus porteri | (Coult.) Nash | Poaceae | 8 |
| Bromus pubescens | Muhl. ex Willd. | Poaceae | 8 |
| Bulbostylis capillaris | (L.) Kunth ex C.B.Clarke | Cyperaceae | 8 |
| Calamagrostis canadensis | (Michx.) P.Beauv. | Poaceae | 8 |
| Calamagrostis inexpansa | A.Gray | Poaceae | 8 |
| Calamagrostis stricta | (Timm) Koeler | Poaceae | 8 |
| Callirhoe alcaeoides | (Michx.) A.Gray | Malvaceae | 8 |
| Callirhoe involucrata | (Torr. & A.Gray) A.Gray | Malvaceae | 8 |
| Callitriche hermaphroditica | L. | Plantaginaceae | 8 |
| Callitriche palustris | L. | Plantaginaceae | 8 |
| Calochortus nuttallii | Torr. | Liliaceae | 8 |
| Caltha palustris | L. | Ranunculaceae | 8 |
| Calystegia sepium | (L.) R.Br. | Convolvulaceae | 8 |
| Calystegia silvatica | Griseb. | Convolvulaceae | 8 |
| Campanula americana | L. | Campanulaceae | 8 |
| Campanula petiolata | A.DC. | Campanulaceae | 8 |
| Campsis radicans | (L.) Bureau | Bignoniaceae | 8 |
| Cardamine bulbosa | (Schreb. ex Muhl.) Britton, Sterns & Poggenb. | Brassicaceae | 8 |
| Cardamine concatenata | (Michx.) O.Schwarz | Brassicaceae | 8 |
| Cardamine pensylvanica | Muhl. ex Willd. | Brassicaceae | 8 |
| Carex aggregata | Mack. | Cyperaceae | 8 |
| Carex albicans | Willd. ex Spreng. | Cyperaceae | 8 |
| Carex annectens | (E.P.Bicknell) E.P.Bicknell | Cyperaceae | 8 |
| Carex aquatilis | Wahlenb. | Cyperaceae | 8 |
| Carex atherodes | Spreng. | Cyperaceae | 8 |
| Carex aurea | Nutt. | Cyperaceae | 8 |
| Carex aureolensis | Steud. | Cyperaceae | 8 |
| Carex austrina | Mack. | Cyperaceae | 8 |
| Carex bebbii | (L.H.Bailey) Olney ex Fernald | Cyperaceae | 8 |
| Carex bicknellii | Britton & A.Br. | Cyperaceae | 8 |
| Carex blanda | Dewey | Cyperaceae | 8 |
| Carex brevior | (Dewey) Mack. ex Lunell | Cyperaceae | 8 |
| Carex bushii | Mack. | Cyperaceae | 8 |
| Carex buxbaumii | Wahlenb. | Cyperaceae | 8 |
| Carex cephalophora | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex conjuncta | Boott | Cyperaceae | 8 |
| Carex crawei | Dewey ex Torr. | Cyperaceae | 8 |
| Carex cristatella | Britton | Cyperaceae | 8 |
| Carex crus-corvi | Shuttlew. ex Kunze | Cyperaceae | 8 |
| Carex davisii | Schwein. & Torr. | Cyperaceae | 8 |
| Carex diandra | Schrank | Cyperaceae | 8 |
| Carex douglasii | Boott | Cyperaceae | 8 |
| Carex duriuscula | C.A.Mey. | Cyperaceae | 8 |
| Carex eburnea | Boott | Cyperaceae | 8 |
| Carex emoryi | Dewey | Cyperaceae | 8 |
| Carex filifolia | Nutt. | Cyperaceae | 8 |
| Carex frankii | Kunth | Cyperaceae | 8 |
| Carex granularis | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex gravida | L.H.Bailey | Cyperaceae | 8 |
| Carex grisea | Wahlenb. | Cyperaceae | 8 |
| Carex haydenii | Dewey | Cyperaceae | 8 |
| Carex hyalinolepis | Steud. | Cyperaceae | 8 |
| Carex hystericina | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex inops | L.H.Bailey | Cyperaceae | 8 |
| Carex interior | L.H.Bailey | Cyperaceae | 8 |
| Carex jamesii | Schwein. | Cyperaceae | 8 |
| Carex lacustris | Willd. | Cyperaceae | 8 |
| Carex leavenworthii | Dewey | Cyperaceae | 8 |
| Carex limosa | L. | Cyperaceae | 8 |
| Carex lupulina | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex meadii | Dewey | Cyperaceae | 8 |
| Carex molesta | Mack. | Cyperaceae | 8 |
| Carex muehlenbergii | Schkuhr ex Willd. | Cyperaceae | 8 |
| Carex peckii | Howe | Cyperaceae | 8 |
| Carex pellita | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex praegracilis | W.Boott | Cyperaceae | 8 |
| Carex prairea | Dewey ex Alph.Wood | Cyperaceae | 8 |
| Carex radiata | (Wahlenb.) Small | Cyperaceae | 8 |
| Carex rosea | Willd. | Cyperaceae | 8 |
| Carex rossii | Boott | Cyperaceae | 8 |
| Carex sartwellii | Dewey | Cyperaceae | 8 |
| Carex scoparia | Schkuhr ex Willd. | Cyperaceae | 8 |
| Carex sparganioides | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex sprengelii | Dewey ex Spreng. | Cyperaceae | 8 |
| Carex squarrosa | L. | Cyperaceae | 8 |
| Carex stipata | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex stricta | Lam. | Cyperaceae | 8 |
| Carex tenera | Dewey | Cyperaceae | 8 |
| Carex texensis | (Torr. ex L.H.Bailey) L.H.Bailey | Cyperaceae | 8 |
| Carex tribuloides | Wahlenb. | Cyperaceae | 8 |
| Carex umbellata | Willd. | Cyperaceae | 8 |
| Carex vulpinoidea | Michx. | Cyperaceae | 8 |
| Carya cordiformis | (Wangenh.) K.Koch | Juglandaceae | 8 |
| Carya ovata | (Mill.) K.Koch | Juglandaceae | 8 |
| Castilleja sessiliflora | Pursh | Orobanchaceae | 8 |
| Catabrosa aquatica | (L.) P.Beauv. | Poaceae | 8 |
| Catalpa speciosa | (Warder) Engelm. | Bignoniaceae | 8 |
| Caulophyllum thalictroides | (L.) Michx. | Berberidaceae | 8 |
| Ceanothus americanus | L. | Rhamnaceae | 8 |
| Ceanothus herbaceus | Raf. | Rhamnaceae | 8 |
| Celastrus scandens | L. | Celastraceae | 8 |
| Celtis occidentalis | L. | Cannabaceae | 8 |
| Cephalanthus occidentalis | L. | Rubiaceae | 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 montanus | Raf. | Rosaceae | 8 |
| Chaerophyllum procumbens | (L.) Crantz | Apiaceae | 8 |
| Chaerophyllum tainturieri | Hook. | Apiaceae | 8 |
| Chaetopappa ericoides | (Torr.) G.L.Nesom | Asteraceae | 8 |
| Chamaecrista fasciculata | (Michx.) Greene | Fabaceae | 8 |
| Chasmanthium latifolium | (Michx.) H.O.Yates | Poaceae | 8 |
| Chenopodium album | L. | Chenopodiaceae | 8 |
| Chenopodium berlandieri | Moq. | Chenopodiaceae | 8 |
| Chenopodium fremontii | S.Watson | Chenopodiaceae | 8 |
| Chenopodium incanum | (S.Watson) A.Heller | Chenopodiaceae | 8 |
| Chenopodium rubrum | L. | Chenopodiaceae | 8 |
| Chloris verticillata | Nutt. | Poaceae | 8 |
| Chloris virgata | Sw. | Poaceae | 8 |
| Chrysopsis villosa | (Pursh) Nutt. ex DC. | Asteraceae | 8 |
| Chrysothamnus viscidiflorus | Nutt. | Asteraceae | 8 |
| Cicuta bulbifera | L. | Apiaceae | 8 |
| Cicuta maculata | L. | Apiaceae | 8 |
| Cinna arundinacea | L. | Poaceae | 8 |
| Circaea canadensis | (L.) Hill | Onagraceae | 8 |
| Cirsium altissimum | (L.) Hill | Asteraceae | 8 |
| Cirsium canescens | Nutt. | Asteraceae | 8 |
| Cirsium discolor | (Muhl. ex Willd.) Spreng. | Asteraceae | 8 |
| Cirsium flodmanii | Arthur | Asteraceae | 8 |
| Cirsium ochrocentrum | A.Gray | Asteraceae | 8 |
| Cirsium undulatum | (Nutt.) Spreng. | Asteraceae | 8 |
| Claytonia virginica | L. | Montiaceae | 8 |
| Clematis fremontii | S.Watson | Ranunculaceae | 8 |
| Clematis hirsutissima | Pursh | Ranunculaceae | 8 |
| Clematis ligusticifolia | Nutt. | Ranunculaceae | 8 |
| Clematis pitcheri | Torr. & A.Gray | Ranunculaceae | 8 |
| Clematis virginiana | L. | Ranunculaceae | 8 |
| Cleome dodecandra | L. | Cleomaceae | 8 |
| Cleome jamesii | (Torr. & A.Gray) Govaerts | Cleomaceae | 8 |
| Cleomella lutea | (Hook.) Roalson & J.C.Hall | Cleomaceae | 8 |
| Cleomella serrulata | (Pursh) Roalson & J.C.Hall | Cleomaceae | 8 |
| Clitoria mariana | L. | Fabaceae | 8 |
| Collinsia parviflora | Douglas ex Lindl. | Plantaginaceae | 8 |
| Collomia linearis | Nutt. | Polemoniaceae | 8 |
| Comandra umbellata | (L.) Nutt. | Santalaceae | 8 |
| Commelina erecta | L. | Commelinaceae | 8 |
| Conoclinium coelestinum | DC. | Asteraceae | 8 |
| Convolvulus equitans | Benth. | Convolvulaceae | 8 |
| Conyza ramosissima | Cronquist | Asteraceae | 8 |
| Corallorhiza maculata | Raf. | Orchidaceae | 8 |
| Corallorhiza odontorhiza | (Willd.) Nutt. | Orchidaceae | 8 |
| Corallorhiza wisteriana | Conrad | Orchidaceae | 8 |
| Coreopsis tinctoria | Nutt. | Asteraceae | 8 |
| Cornus drummondii | C.A.Mey. | Cornaceae | 8 |
| Cornus obliqua | Raf. | Cornaceae | 8 |
| Cornus racemosa | Lam. | Cornaceae | 8 |
| Cornus sericea | L. | Cornaceae | 8 |
| Corydalis aurea | Willd. | Papaveraceae | 8 |
| Corydalis flavula | (Raf.) DC. | Papaveraceae | 8 |
| Corydalis micrantha | (Engelm. ex A.Gray) A.Gray ex J.M.Coult. | Papaveraceae | 8 |
| Corylus americana | Walter | Betulaceae | 8 |
| Crataegus calpodendron | (Ehrh.) Medik. | Rosaceae | 8 |
| Crataegus macracantha | (Lindl.) Lodd. ex Loudon | Rosaceae | 8 |
| Crataegus mollis | (Torr. & A.Gray) Scheele | Rosaceae | 8 |
| Crepis acuminata | Nutt. | Asteraceae | 8 |
| Crepis atribarba | A.Heller | Asteraceae | 8 |
| Crocanthemum bicknellii | (Fernald) Janch. | Cistaceae | 8 |
| Crotalaria sagittalis | L. | Fabaceae | 8 |
| Croton capitatus | Michx. | Euphorbiaceae | 8 |
| Croton glandulosus | L. | Euphorbiaceae | 8 |
| Croton monanthogynus | Michx. | Euphorbiaceae | 8 |
| Croton texensis | (Klotzsch) Müll.Arg. | Euphorbiaceae | 8 |
| Cryptantha fendleri | (A.Gray) Greene | Boraginaceae | 8 |
| Cryptantha minima | Rydb. | Boraginaceae | 8 |
| Cryptotaenia canadensis | (L.) DC. | Apiaceae | 8 |
| Cucurbita foetidissima | Kunth | Cucurbitaceae | 8 |
| Cuphea viscosissima | Jacq. | Lythraceae | 8 |
| Cuscuta campestris | Yunck. | Convolvulaceae | 8 |
| Cuscuta cephalanthi | Engelm. | Convolvulaceae | 8 |
| Cuscuta coryli | Engelm. | Convolvulaceae | 8 |
| Cuscuta cuspidata | Engelm. | Convolvulaceae | 8 |
| Cuscuta glomerata | Choisy | Convolvulaceae | 8 |
| Cuscuta gronovii | Willd. | Convolvulaceae | 8 |
| Cuscuta indecora | Choisy | Convolvulaceae | 8 |
| Cuscuta pentagona | Engelm. | Convolvulaceae | 8 |
| Cyclanthera naudiniana | Cogn. | Cucurbitaceae | 8 |
| Cymopterus glomeratus | (Nutt.) DC. | Apiaceae | 8 |
| Cynanchum laeve | (Michx.) Pers. | Apocynaceae | 8 |
| Cyperus acuminatus | Torr. & Hook. | Cyperaceae | 8 |
| Cyperus bipartitus | Torr. | Cyperaceae | 8 |
| Cyperus diandrus | Torr. | Cyperaceae | 8 |
| Cyperus esculentus | L. | Cyperaceae | 8 |
| Cyperus lupulinus | (Biehler) Marcks | Cyperaceae | 8 |
| Cyperus odoratus | L. | Cyperaceae | 8 |
| Cyperus squarrosus | L. | Cyperaceae | 8 |
| Cyperus strigosus | L. | Cyperaceae | 8 |
| Cyperus subsquarrosus | (Muhl.) Bauters | Cyperaceae | 8 |
| Cypripedium candidum | Muhl. ex Willd. | Orchidaceae | 8 |
| Cypripedium parviflorum | Salisb. | Orchidaceae | 8 |
| Cystopteris bulbifera | (L.) Bernh. | Cystopteridaceae | 8 |
| Cystopteris fragilis | (L.) Bernh. | Cystopteridaceae | 8 |
| Cystopteris protrusa | (Weath.) Blasdell | Cystopteridaceae | 8 |
| Cystopteris tenuis | (Michx.) Desv. | Cystopteridaceae | 8 |
| Dactylorhiza viridis | (L.) R.M.Bateman, Pridgeon & M.W.Chase | Orchidaceae | 8 |
| Dalea aurea | Nutt. ex Pursh | Fabaceae | 8 |
| Dalea candida | Willd. | Fabaceae | 8 |
| Dalea cylindriceps | Barneby | Fabaceae | 8 |
| Dalea enneandra | Nutt. | Fabaceae | 8 |
| Dalea leporina | (Aiton) Bullock | Fabaceae | 8 |
| Dalea villosa | (Nutt.) Spreng. | Fabaceae | 8 |
| Danthonia spicata | (L.) Roem. & Schult. | Poaceae | 8 |
| Dasistoma macrophylla | (Nutt.) Raf. | Orobanchaceae | 8 |
| Delphinium bicolor | Nutt. | Ranunculaceae | 8 |
| Delphinium carolinianum | Walter | Ranunculaceae | 8 |
| Delphinium exaltatum | Aiton | Ranunculaceae | 8 |
| Delphinium geyeri | Greene | Ranunculaceae | 8 |
| Delphinium tricorne | Michx. | Ranunculaceae | 8 |
| Descurainia pinnata | (Walter) Britton | Brassicaceae | 8 |
| Desmanthus illinoensis | (Michx.) MacMill. ex B.L.Rob. & Fernald | Fabaceae | 8 |
| Desmodium canadense | (L.) DC. | Fabaceae | 8 |
| Desmodium canescens | (L.) DC. | Fabaceae | 8 |
| Diaperia prolifera | (Nutt. ex DC.) Nutt. | Asteraceae | 8 |
| Diarrhena americana | P.Beauv. | Poaceae | 8 |
| Dicentra cucullaria | (L.) Bernh. | Papaveraceae | 8 |
| Dichanthelium depauperatum | (Muhl.) Gould | Poaceae | 8 |
| Dichanthelium implicatum | (Scribn.) Kerguélen | Poaceae | 8 |
| Dichanthelium lanuginosum | (Elliott) Gould | Poaceae | 8 |
| Dichanthelium latifolium | (L.) Harvill | Poaceae | 8 |
| Dichanthelium leibergii | (Vasey) Freckmann | Poaceae | 8 |
| Dichanthelium linearifolium | (Scribn.) Gould | Poaceae | 8 |
| Dichanthelium oligosanthes | (Schult.) Gould | Poaceae | 8 |
| Dichanthelium praecocius | (Hitchc. & Chase) Mohlenbr. | Poaceae | 8 |
| Dieteria canescens | (Pursh) Nutt. | Asteraceae | 8 |
| Digitaria cognata | (Schult.) Pilg. | Poaceae | 8 |
| Dioscorea villosa | L. | Dioscoreaceae | 8 |
| Diplachne fusca | (L.) P.Beauv. | Poaceae | 8 |
| Distichlis spicata | (L.) Greene | Poaceae | 8 |
| Doellingeria umbellata | (Mill.) Nees | Asteraceae | 8 |
| Draba nemorosa | L. | Brassicaceae | 8 |
| Dracocephalum parviflorum | Nutt. | Lamiaceae | 8 |
| Drymocallis arguta | (Pursh) Rydb. | Rosaceae | 8 |
| Dryopteris carthusiana | (Vill.) H.P.Fuchs | Dryopteridaceae | 8 |
| Dryopteris cristata | (L.) A.Gray | Dryopteridaceae | 8 |
| Dulichium arundinaceum | (L.) Britton | Cyperaceae | 8 |
| Dyssodia papposa | (Vent.) Hitchc. | Asteraceae | 8 |
| Echinacea angustifolia | DC. | Asteraceae | 8 |
| Echinacea pallida | (Nutt.) Nutt. | Asteraceae | 8 |
| Echinochloa muricata | (P.Beauv.) Fernald | Poaceae | 8 |
| Echinocystis lobata | (Michx.) Torr. & A.Gray | Cucurbitaceae | 8 |
| Echinodorus berteroi | (Spreng.) Fassett | Alismataceae | 8 |
| Eclipta prostrata | (L.) L. | Asteraceae | 8 |
| Elatine brachysperma | A.Gray | Elatinaceae | 8 |
| Eleocharis acicularis | (L.) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis atropurpurea | (Retz.) J.Presl & C.Presl | Cyperaceae | 8 |
| Eleocharis compressa | Sull. | Cyperaceae | 8 |
| Eleocharis engelmannii | Steud. | Cyperaceae | 8 |
| Eleocharis erythropoda | Steud. | Cyperaceae | 8 |
| Eleocharis geniculata | (L.) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis macrostachya | Britton | Cyperaceae | 8 |
| Eleocharis obtusa | (Willd.) Schult. | Cyperaceae | 8 |
| Eleocharis palustris | (L.) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis quinqueflora | (Hartmann) O.Schwarz | Cyperaceae | 8 |
| Eleocharis rostellata | (Torr.) Torr. | Cyperaceae | 8 |
| Eleocharis uniglumis | (Link) Schult. | Cyperaceae | 8 |
| Ellisia nyctelea | (L.) L. | Hydrophyllaceae | 8 |
| Elodea canadensis | Michx. | Hydrocharitaceae | 8 |
| Elodea nuttallii | (Planch.) H.St.John | Hydrocharitaceae | 8 |
| Elymus albicans | (Scribn. & J.G.Sm.) Á.Löve | Poaceae | 8 |
| Elymus canadensis | L. | Poaceae | 8 |
| Elymus curvatus | Piper | Poaceae | 8 |
| Elymus elymoides | (Raf.) Swezey | Poaceae | 8 |
| Elymus hystrix | L. | Poaceae | 8 |
| Elymus lanceolatus | (Scribn. & J.G.Sm.) Gould | Poaceae | 8 |
| Elymus longifolius | (J.G.Sm.) Gould | Poaceae | 8 |
| Elymus macgregorii | R.E.Brooks & J.J.N.Campb. | Poaceae | 8 |
| Elymus smithii | (Rydb.) Gould | Poaceae | 8 |
| Elymus villosus | Muhl. ex Willd. | Poaceae | 8 |
| Elymus violaceus | (Hornem.) J.Feilberg | Poaceae | 8 |
| Elymus virginicus | L. | Poaceae | 8 |
| Engelmannia peristenia | (Raf.) Goodman & C.A.Lawson | Asteraceae | 8 |
| Epilobium angustifolium | L. | Onagraceae | 8 |
| Epilobium ciliatum | Raf. | Onagraceae | 8 |
| Epilobium coloratum | Muhl. ex Willd. | Onagraceae | 8 |
| Epilobium leptophyllum | Raf. | Onagraceae | 8 |
| Equisetum arvense | L. | Equisetaceae | 8 |
| Equisetum fluviatile | L. | Equisetaceae | 8 |
| Equisetum hyemale | L. | Equisetaceae | 8 |
| Equisetum laevigatum | A.Braun | Equisetaceae | 8 |
| Eragrostis hypnoides | (Lam.) Britton, Sterns & Poggenb. | Poaceae | 8 |
| Eragrostis pectinacea | (Michx.) Nees | Poaceae | 8 |
| Eragrostis reptans | (Michx.) Nees | Poaceae | 8 |
| Eragrostis secundiflora | J.Presl | Poaceae | 8 |
| Eragrostis spectabilis | (Pursh) Steud. | Poaceae | 8 |
| Eragrostis trichodes | (Nutt.) Alph.Wood | Poaceae | 8 |
| Erechtites hieraciifolius | (L.) Raf. ex DC. | Asteraceae | 8 |
| Ericameria nauseosa | (Pursh) G.L.Nesom & G.I.Baird | Asteraceae | 8 |
| Ericameria parryi | (A.Gray) G.L.Nesom & G.I.Baird | Asteraceae | 8 |
| Erigeron bellidiastrum | Nutt. | Asteraceae | 8 |
| Erigeron caespitosus | Nutt. | Asteraceae | 8 |
| Erigeron canadensis | L. | Asteraceae | 8 |
| Erigeron divergens | Torr. & A.Gray | Asteraceae | 8 |
| Erigeron flagellaris | A.Gray | Asteraceae | 8 |
| Erigeron lonchophyllus | Hook. | Asteraceae | 8 |
| Erigeron ochroleucus | Nutt. | Asteraceae | 8 |
| Erigeron philadelphicus | L. | Asteraceae | 8 |
| Erigeron pumilus | Nutt. | Asteraceae | 8 |
| Erigeron strigosus | Muhl. ex Willd. | Asteraceae | 8 |
| Erigeron vetensis | Rydb. | Asteraceae | 8 |
| Eriochloa contracta | Hitchc. | Poaceae | 8 |
| Eriocoma hymenoides | (Roem. & Schult.) Rydb. | Poaceae | 8 |
| Eriogonum alatum | Torr. | Polygonaceae | 8 |
| Eriogonum annuum | Nutt. | Polygonaceae | 8 |
| Eriogonum brevicaule | Nutt. | Polygonaceae | 8 |
| Eriogonum cernuum | Nutt. | Polygonaceae | 8 |
| Eriogonum effusum | Nutt. | Polygonaceae | 8 |
| Eriogonum flavum | Nutt. | Polygonaceae | 8 |
| Eriogonum pauciflorum | Pursh | Polygonaceae | 8 |
| Eriophorum angustifolium | Honck. | Cyperaceae | 8 |
| Eriophorum chamissonis | C.A.Mey. | Cyperaceae | 8 |
| Eriophorum gracile | Roth | Cyperaceae | 8 |
| Eryngium yuccifolium | Michx. | Apiaceae | 8 |
| Erysimum asperum | (Nutt.) DC. | Brassicaceae | 8 |
| Erythranthe geyeri | (Torr.) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe guttata | (DC.) G.L.Nesom | Phrymaceae | 8 |
| Erythronium albidum | Nutt. | Liliaceae | 8 |
| Erythronium mesochoreum | Knerr | Liliaceae | 8 |
| Euonymus atropurpureus | Jacq. | Celastraceae | 8 |
| Eupatorium altissimum | L. | Asteraceae | 8 |
| Eupatorium perfoliatum | L. | Asteraceae | 8 |
| Eupatorium serotinum | Michx. | Asteraceae | 8 |
| Euphorbia brachycera | Engelm. | Euphorbiaceae | 8 |
| Euphorbia corollata | L. | Euphorbiaceae | 8 |
| Euphorbia dentata | Michx. | Euphorbiaceae | 8 |
| Euphorbia fendleri | Torr. & A.Gray | Euphorbiaceae | 8 |
| Euphorbia geyeri | Engelm. | Euphorbiaceae | 8 |
| Euphorbia glyptosperma | Engelm. | Euphorbiaceae | 8 |
| Euphorbia heterophylla | L. | Euphorbiaceae | 8 |
| Euphorbia hexagona | Nutt. ex Spreng. | Euphorbiaceae | 8 |
| Euphorbia maculata | L. | Euphorbiaceae | 8 |
| Euphorbia marginata | Pursh | Euphorbiaceae | 8 |
| Euphorbia missurica | Raf. | Euphorbiaceae | 8 |
| Euphorbia nutans | Lag. | Euphorbiaceae | 8 |
| Euphorbia prostrata | Aiton | Euphorbiaceae | 8 |
| Euphorbia serpens | Kunth | Euphorbiaceae | 8 |
| Euphorbia serpillifolia | Pers. | Euphorbiaceae | 8 |
| Euphorbia spathulata | Lam. | Euphorbiaceae | 8 |
| Euphorbia stictospora | Engelm. | Euphorbiaceae | 8 |
| Euploca convolvulacea | Nutt. | Heliotropiaceae | 8 |
| Eustoma russellianum | (Hook.) G.Don | Gentianaceae | 8 |
| Euthamia gymnospermoides | Greene | Asteraceae | 8 |
| Euthamia occidentalis | Nutt. | Asteraceae | 8 |
| Eutrochium maculatum | (L.) E.E.Lamont | Asteraceae | 8 |
| Eutrochium purpureum | (L.) E.E.Lamont | Asteraceae | 8 |
| Evolvulus nuttallianus | Schult. | Convolvulaceae | 8 |
| Fallopia scandens | (L.) Holub | Polygonaceae | 8 |
| Festuca kingii | (S.Watson) Cassidy | Poaceae | 8 |
| Festuca octoflora | Walter | Poaceae | 8 |
| Festuca paradoxa | Desv. | Poaceae | 8 |
| Festuca rubra | L. | Poaceae | 8 |
| Festuca subverticillata | (Pers.) E.B.Alexeev | Poaceae | 8 |
| Fimbristylis autumnalis | (L.) Roem. & Schult. | Cyperaceae | 8 |
| Fimbristylis puberula | (Michx.) Vahl | Cyperaceae | 8 |
| Fimbristylis vahlii | (Lam.) Link | Cyperaceae | 8 |
| Fragaria vesca | L. | Rosaceae | 8 |
| Fragaria virginiana | Mill. | Rosaceae | 8 |
| Fraxinus americana | L. | Oleaceae | 8 |
| Fraxinus pennsylvanica | Marshall | Oleaceae | 8 |
| Fritillaria atropurpurea | Nutt. | Liliaceae | 8 |
| Froelichia floridana | (Nutt.) Moq. | Amaranthaceae | 8 |
| Froelichia gracilis | (Hook.) Moq. | Amaranthaceae | 8 |
| Fuirena simplex | Vahl | Cyperaceae | 8 |
| Gaillardia pulchella | Foug. | Asteraceae | 8 |
| Galearis spectabilis | (L.) Raf. | Orchidaceae | 8 |
| Galium obtusum | Bigelow | Rubiaceae | 8 |
| Galium trifidum | L. | Rubiaceae | 8 |
| Galium triflorum | Michx. | Rubiaceae | 8 |
| Gentiana alba | Muhl. ex J.McNab | Gentianaceae | 8 |
| Gentiana andrewsii | Griseb. | Gentianaceae | 8 |
| Gentiana puberulenta | J.S.Pringle | Gentianaceae | 8 |
| Geranium carolinianum | L. | Geraniaceae | 8 |
| Geranium maculatum | L. | Geraniaceae | 8 |
| Geranium viscosissimum | Fisch. & C.A.Mey. | Geraniaceae | 8 |
| Geum aleppicum | Jacq. | Rosaceae | 8 |
| Geum canadense | Jacq. | Rosaceae | 8 |
| Geum laciniatum | Murray | Rosaceae | 8 |
| Geum macrophyllum | Willd. | Rosaceae | 8 |
| Geum vernum | (Raf.) Torr. & A.Gray | Rosaceae | 8 |
| Gleditsia triacanthos | L. | Fabaceae | 8 |
| Glyceria borealis | (Nash) Batch. | Poaceae | 8 |
| Glyceria grandis | S.Watson | Poaceae | 8 |
| Glyceria striata | (Lam.) Hitchc. | Poaceae | 8 |
| Glycyrrhiza lepidota | Pursh | Fabaceae | 8 |
| Gnaphalium palustre | Nutt. | Asteraceae | 8 |
| Goodyera oblongifolia | Raf. | Orchidaceae | 8 |
| Gratiola neglecta | Torr. | Plantaginaceae | 8 |
| Grindelia ciliata | (Nutt.) Spreng. | Asteraceae | 8 |
| Grindelia hirsutula | Hook. & Arn. | Asteraceae | 8 |
| Grindelia squarrosa | (Pursh) Dunal | Asteraceae | 8 |
| Gutierrezia dracunculoides | (DC.) O.Hoffm. | Asteraceae | 8 |
| Gutierrezia sarothrae | (Pursh) Britton & Rusby | Asteraceae | 8 |
| Gymnocladus dioicus | (L.) K.Koch | Fabaceae | 8 |
| Hackelia deflexa | (Wahlenb.) Opiz | Boraginaceae | 8 |
| Hackelia floribunda | (Lehm.) I.M.Johnst. | Boraginaceae | 8 |
| Hackelia virginiana | (L.) I.M.Johnst. | Boraginaceae | 8 |
| Halerpestes cymbalaria | Greene | Ranunculaceae | 8 |
| Hedeoma drummondii | Benth. | Lamiaceae | 8 |
| Hedeoma hispida | Pursh | Lamiaceae | 8 |
| Hedeoma pulegioides | (L.) Pers. | Lamiaceae | 8 |
| Hedysarum alpinum | L. | Fabaceae | 8 |
| Helenium autumnale | L. | Asteraceae | 8 |
| Helianthus ciliaris | DC. | Asteraceae | 8 |
| Helianthus grosseserratus | M.Martens | Asteraceae | 8 |
| Helianthus hirsutus | Raf. | Asteraceae | 8 |
| Helianthus maximiliani | Schrad. | Asteraceae | 8 |
| Helianthus mollis | Lam. | Asteraceae | 8 |
| Helianthus nuttallii | Torr. & A.Gray | Asteraceae | 8 |
| Helianthus pauciflorus | Nutt. | Asteraceae | 8 |
| Helianthus petiolaris | Nutt. | Asteraceae | 8 |
| Helianthus salicifolius | A.Dietr. | Asteraceae | 8 |
| Helianthus tuberosus | L. | Asteraceae | 8 |
| Heliopsis helianthoides | Sweet | Asteraceae | 8 |
| Heliotropium curassavicum | L. | Heliotropiaceae | 8 |
| Heracleum maximum | W.Bartram | Apiaceae | 8 |
| Hesperostipa comata | (Trin. & Rupr.) Barkworth | Poaceae | 8 |
| Hesperostipa spartea | (Trin.) Barkworth | Poaceae | 8 |
| Heteranthera dubia | (Jacq.) MacMill. | Pontederiaceae | 8 |
| Heteranthera limosa | (Sw.) Willd. | Pontederiaceae | 8 |
| Heterotheca subaxillaris | (Lam.) Britton & Rusby | Asteraceae | 8 |
| Heuchera richardsonii | R.Br. | Saxifragaceae | 8 |
| Hieracium longipilum | Torr. ex Hook. | Asteraceae | 8 |
| Hieracium umbellatum | L. | Asteraceae | 8 |
| Hippuris vulgaris | L. | Plantaginaceae | 8 |
| Hordeum jubatum | L. | Poaceae | 8 |
| Humulus americanus | Nutt. | Cannabaceae | 8 |
| Humulus neomexicanus | (A.Nelson & Cockerell) Rydb. | Cannabaceae | 8 |
| Hydrophyllum appendiculatum | Michx. | Hydrophyllaceae | 8 |
| Hydrophyllum virginianum | L. | Hydrophyllaceae | 8 |
| Hymenopappus filifolius | Hook. | Asteraceae | 8 |
| Hymenopappus scabiosaeus | L'Hér. | Asteraceae | 8 |
| Hymenopappus tenuifolius | Pursh | Asteraceae | 8 |
| Hypericum fraseri | (Spach) Steud. | Hypericaceae | 8 |
| Hypericum majus | (A.Gray) Britton | Hypericaceae | 8 |
| Hypericum mutilum | L. | Hypericaceae | 8 |
| Hypericum punctatum | Lam. | Hypericaceae | 8 |
| Hypericum sphaerocarpum | Michx. | Hypericaceae | 8 |
| Hypopitys monotropa | Crantz | Ericaceae | 8 |
| Hypoxis hirsuta | (L.) Coville | Hypoxidaceae | 8 |
| Impatiens capensis | Meerb. | Balsaminaceae | 8 |
| Impatiens pallida | Nutt. | Balsaminaceae | 8 |
| Ipomoea leptophylla | Torr. | Convolvulaceae | 8 |
| Ipomoea pandurata | G.Mey. | Convolvulaceae | 8 |
| Ipomopsis congesta | (Hook.) V.E.Grant | Polemoniaceae | 8 |
| Ipomopsis longiflora | (Torr.) V.E.Grant | Polemoniaceae | 8 |
| Ipomopsis spicata | (Nutt.) V.E.Grant | Polemoniaceae | 8 |
| Iris missouriensis | Nutt. | Iridaceae | 8 |
| Iris virginica | L. | Iridaceae | 8 |
| Iva annua | L. | Asteraceae | 8 |
| Iva axillaris | Pursh | Asteraceae | 8 |
| Juglans nigra | L. | Juglandaceae | 8 |
| Juncus acuminatus | Michx. | Juncaceae | 8 |
| Juncus alpinoarticulatus | Chaix | Juncaceae | 8 |
| Juncus articulatus | L. | Juncaceae | 8 |
| Juncus balticus | Willd. | Juncaceae | 8 |
| Juncus bufonius | L. | Juncaceae | 8 |
| Juncus canadensis | J.Gay ex Laharpe | Juncaceae | 8 |
| Juncus dudleyi | Wiegand | Juncaceae | 8 |
| Juncus effusus | L. | Juncaceae | 8 |
| Juncus interior | Wiegand | Juncaceae | 8 |
| Juncus marginatus | Rostk. | Juncaceae | 8 |
| Juncus nodosus | L. | Juncaceae | 8 |
| Juncus scirpoides | Lam. | Juncaceae | 8 |
| Juncus tenuis | Willd. | Juncaceae | 8 |
| Juncus torreyi | Coville | Juncaceae | 8 |
| Juniperus communis | L. | Cupressaceae | 8 |
| Juniperus scopulorum | Sarg. | Cupressaceae | 8 |
| Juniperus virginiana | L. | Cupressaceae | 8 |
| Koeleria macrantha | (Ledeb.) Schult. | Poaceae | 8 |
| Krascheninnikovia ceratoides | (L.) Gueldenst. | Chenopodiaceae | 8 |
| Krigia cespitosa | (Raf.) K.L.Chambers | Asteraceae | 8 |
| Lactuca canadensis | L. | Asteraceae | 8 |
| Lactuca floridana | (L.) Gaertn. | Asteraceae | 8 |
| Lactuca ludoviciana | (Nutt.) Riddell | Asteraceae | 8 |
| Lactuca oblongifolia | Nutt. | Asteraceae | 8 |
| Ladeania lanceolata | (Pursh) Reveal & A.N.Egan | Fabaceae | 8 |
| Laportea canadensis | (L.) Wedd. | Urticaceae | 8 |
| Lappula occidentalis | (S.Watson) Greene | Boraginaceae | 8 |
| Lathyrus decaphyllus | Pursh | Fabaceae | 8 |
| Lathyrus ochroleucus | Hook. | Fabaceae | 8 |
| Lathyrus palustris | L. | Fabaceae | 8 |
| Lechea mucronata | Raf. | Cistaceae | 8 |
| Lechea tenuifolia | Michx. | Cistaceae | 8 |
| Leersia oryzoides | (L.) Sw. | Poaceae | 8 |
| Leersia virginica | Willd. | Poaceae | 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 |
| Lemna turionifera | Landolt | Araceae | 8 |
| Lepidium densiflorum | Schrad. | Brassicaceae | 8 |
| Lepidium virginicum | L. | Brassicaceae | 8 |
| Lespedeza capitata | Michx. | Fabaceae | 8 |
| Lespedeza violacea | (L.) Pers. | Fabaceae | 8 |
| Leucocrinum montanum | Nutt. ex A.Gray | Asparagaceae | 8 |
| Leucospora multifida | (Michx.) Nutt. | Plantaginaceae | 8 |
| Leymus cinereus | (Scribn. & Merr.) Á.Löve | Poaceae | 8 |
| Liatris aspera | Michx. | Asteraceae | 8 |
| Liatris punctata | Hook. | Asteraceae | 8 |
| Liatris pycnostachya | Michx. | Asteraceae | 8 |
| Liatris spicata | (L.) Willd. | Asteraceae | 8 |
| Liatris squarrosa | (L.) Willd. | Asteraceae | 8 |
| Lilium michiganense | Farw. | Liliaceae | 8 |
| Lilium philadelphicum | L. | Liliaceae | 8 |
| Limosella aquatica | L. | Plantaginaceae | 8 |
| Linanthus caespitosus | (Nutt.) J.M.Porter & L.A.Johnson | Polemoniaceae | 8 |
| Lindernia dubia | (L.) Pennell | Linderniaceae | 8 |
| Linum compactum | A.Nelson | Linaceae | 8 |
| Linum lewisii | Pursh | Linaceae | 8 |
| Linum puberulum | (Engelm.) A.Heller | Linaceae | 8 |
| Linum rigidum | Pursh | Linaceae | 8 |
| Linum sulcatum | Riddell | Linaceae | 8 |
| Liparis loeselii | (L.) Rich. | Orchidaceae | 8 |
| Lithophragma parviflorum | (Hook.) Nutt. | Saxifragaceae | 8 |
| Lithospermum canescens | Lehm. | Boraginaceae | 8 |
| Lithospermum caroliniense | (J.F.Gmel.) MacMill. | Boraginaceae | 8 |
| Lithospermum incisum | Lehm. | Boraginaceae | 8 |
| Lithospermum occidentale | (Mack.) Weakley, Witsell & D.Estes | Boraginaceae | 8 |
| Lobelia cardinalis | L. | Campanulaceae | 8 |
| Lobelia inflata | L. | Campanulaceae | 8 |
| Lobelia siphilitica | L. | Campanulaceae | 8 |
| Lobelia spicata | Lam. | Campanulaceae | 8 |
| Loeflingia squarrosa | Nutt. | Caryophyllaceae | 8 |
| Lomatium foeniculaceum | (Nutt.) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium orientale | J.M.Coult. & Rose | Apiaceae | 8 |
| Lonicera dioica | L. | Caprifoliaceae | 8 |
| Ludwigia alternifolia | L. | Onagraceae | 8 |
| Ludwigia palustris | (L.) Elliott | Onagraceae | 8 |
| Ludwigia peploides | (Kunth) P.H.Raven | Onagraceae | 8 |
| Lupinus argenteus | Pursh | Fabaceae | 8 |
| Lupinus pusillus | Pursh | Fabaceae | 8 |
| Lycopus americanus | Muhl. ex W.P.C.Barton | Lamiaceae | 8 |
| Lycopus asper | Greene | Lamiaceae | 8 |
| Lycopus uniflorus | Michx. | Lamiaceae | 8 |
| Lycopus virginicus | L. | Lamiaceae | 8 |
| Lygodesmia juncea | (Pursh) Sweet | Asteraceae | 8 |
| Lysimachia ciliata | L. | Primulaceae | 8 |
| Lysimachia hybrida | Michx. | Primulaceae | 8 |
| Lysimachia maritima | (L.) Galasso, Banfi & Soldano | Primulaceae | 8 |
| Lysimachia minima | (L.) U.Manns & Anderb. | Primulaceae | 8 |
| Lysimachia thyrsiflora | L. | Primulaceae | 8 |
| Lythrum alatum | Pursh | Lythraceae | 8 |
| Machaeranthera tanacetifolia | (Kunth) Nees | Asteraceae | 8 |
| Maianthemum canadense | Desf. | Asparagaceae | 8 |
| Maianthemum racemosum | (L.) Link | Asparagaceae | 8 |
| Maianthemum stellatum | (L.) Link | Asparagaceae | 8 |
| Malus ioensis | (Alph.Wood) Britton | Rosaceae | 8 |
| Marsilea vestita | Hook. & Grev. | Marsileaceae | 8 |
| Melica nitens | (Scribn.) Nutt. ex Piper | Poaceae | 8 |
| Menispermum canadense | L. | Menispermaceae | 8 |
| Mentha canadensis | L. | Lamiaceae | 8 |
| Mentzelia albicaulis | (Douglas ex Hook.) Douglas ex Torr. & A.Gray | Loasaceae | 8 |
| Mentzelia decapetala | (Sims) Urb. | Loasaceae | 8 |
| Mentzelia multiflora | (Nutt.) A.Gray | Loasaceae | 8 |
| Mentzelia nuda | (Pursh) Torr. & A.Gray | Loasaceae | 8 |
| Mentzelia oligosperma | Nutt. ex Sims | Loasaceae | 8 |
| Menyanthes trifoliata | L. | Menyanthaceae | 8 |
| Mertensia lanceolata | (Pursh) DC. | Boraginaceae | 8 |
| Microsteris gracilis | (Hook.) Greene | Polemoniaceae | 8 |
| Mimosa nuttallii | (Raspail) B.L.Turner | Fabaceae | 8 |
| Mimulus alatus | Aiton | Phrymaceae | 8 |
| Mimulus ringens | L. | Phrymaceae | 8 |
| Mirabilis albida | (Walter) Heimerl | Nyctaginaceae | 8 |
| Mirabilis glabra | (S.Watson) Standl. | Nyctaginaceae | 8 |
| Mirabilis linearis | (Pursh) Heimerl | Nyctaginaceae | 8 |
| Moehringia lateriflora | (L.) Fenzl | Caryophyllaceae | 8 |
| Mollugo verticillata | L. | Molluginaceae | 8 |
| Monarda bradburyana | L.C.Beck | Lamiaceae | 8 |
| Monarda fistulosa | L. | Lamiaceae | 8 |
| Monarda pectinata | Nutt. | Lamiaceae | 8 |
| Monotropa uniflora | L. | Ericaceae | 8 |
| Morus rubra | L. | Moraceae | 8 |
| Muenchhusia laevis | (All.) M.M.Hanes & R.L.Barrett | Malvaceae | 8 |
| Muhlenbergia asperifolia | (Nees & Meyen ex Trin.) Parodi | Poaceae | 8 |
| Muhlenbergia bushii | R.W.Pohl | Poaceae | 8 |
| Muhlenbergia cuspidata | (Torr. ex Hook.) Rydb. | Poaceae | 8 |
| Muhlenbergia frondosa | (Poir.) Fernald | Poaceae | 8 |
| Muhlenbergia glomerata | (Willd.) Trin. | Poaceae | 8 |
| Muhlenbergia mexicana | (L.) Trin. | Poaceae | 8 |
| Muhlenbergia minutissima | (Steud.) Swallen | Poaceae | 8 |
| Muhlenbergia multiflora | Columbus | Poaceae | 8 |
| Muhlenbergia paniculata | (Nutt.) P.M.Peterson | Poaceae | 8 |
| Muhlenbergia racemosa | (Michx.) Britton, Sterns & Poggenb. | Poaceae | 8 |
| Muhlenbergia richardsonis | (Trin.) Rydb. | Poaceae | 8 |
| Muhlenbergia schreberi | J.F.Gmel. | Poaceae | 8 |
| Muhlenbergia sylvatica | Torr. | Poaceae | 8 |
| Muhlenbergia tenuiflora | (Willd.) Britton, Sterns & Poggenb. | Poaceae | 8 |
| Munroa squarrosa | (Nutt.) Torr. | Poaceae | 8 |
| Musineon divaricatum | (Pursh) Nutt. | Apiaceae | 8 |
| Musineon tenuifolium | Nutt. | Apiaceae | 8 |
| Myosotis laxa | Lehm. | Boraginaceae | 8 |
| Myosotis verna | Nutt. | Boraginaceae | 8 |
| Myriophyllum pinnatum | (Walter) Britton, Sterns & Poggenb. | Haloragaceae | 8 |
| Myriophyllum sibiricum | Kom. | Haloragaceae | 8 |
| Myriophyllum verticillatum | L. | Haloragaceae | 8 |
| Nabalus racemosus | (Michx.) Hook. | Asteraceae | 8 |
| Najas guadalupensis | (Spreng.) Magnus | Hydrocharitaceae | 8 |
| Nassella viridula | (Trin.) Barkworth | Poaceae | 8 |
| Navarretia intertexta | Hook. | Polemoniaceae | 8 |
| Nelumbo lutea | (Willd.) Pers. | Nelumbonaceae | 8 |
| Nothocalais cuspidata | (Pursh) Greene | Asteraceae | 8 |
| Nuphar variegata | Engelm. ex Durand | Nymphaeaceae | 8 |
| Nuttallanthus canadensis | (L.) D.A.Sutton | Plantaginaceae | 8 |
| Nuttallanthus texanus | (Scheele) D.A.Sutton | Plantaginaceae | 8 |
| Nymphaea odorata | Aiton | Nymphaeaceae | 8 |
| Oenothera albicaulis | Nutt. ex Pursh | Onagraceae | 8 |
| Oenothera biennis | L. | Onagraceae | 8 |
| Oenothera canescens | Torr. | Onagraceae | 8 |
| Oenothera cespitosa | Nutt. | Onagraceae | 8 |
| Oenothera coronopifolia | Torr. & A.Gray | Onagraceae | 8 |
| Oenothera curtiflora | W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera filiformis | (Small) W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera flava | (A.Nelson) Garrett | Onagraceae | 8 |
| Oenothera glaucifolia | W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera grandis | Smyth | Onagraceae | 8 |
| Oenothera laciniata | Hill | Onagraceae | 8 |
| Oenothera lavandulifolia | Torr. & A.Gray | Onagraceae | 8 |
| Oenothera macrocarpa | Nutt. | Onagraceae | 8 |
| Oenothera nuttallii | Torr. & A.Gray | Onagraceae | 8 |
| Oenothera pallida | Lindl. | Onagraceae | 8 |
| Oenothera perennis | L. | Onagraceae | 8 |
| Oenothera rhombipetala | Nutt. ex Torr. & A.Gray | Onagraceae | 8 |
| Oenothera serrulata | Nutt. | Onagraceae | 8 |
| Oenothera speciosa | Nutt. | Onagraceae | 8 |
| Oenothera suffrutescens | (Ser.) W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera villosa | Thunb. | Onagraceae | 8 |
| Onoclea sensibilis | L. | Onocleaceae | 8 |
| Ophioglossum engelmannii | Prantl | Ophioglossaceae | 8 |
| Ophioglossum pusillum | Raf. | Ophioglossaceae | 8 |
| Opuntia cymochila | Engelm. & J.M.Bigelow | Cactaceae | 8 |
| Opuntia fragilis | (Nutt.) Haw. | Cactaceae | 8 |
| Opuntia polyacantha | Haw. | Cactaceae | 8 |
| Opuntia tortispina | Engelm. & J.M.Bigelow | Cactaceae | 8 |
| Oreocarya cana | A.Nelson | Boraginaceae | 8 |
| Oreocarya glomerata | Greene | Boraginaceae | 8 |
| Oreocarya suffruticosa | (Torr.) Greene | Boraginaceae | 8 |
| Oreocarya thyrsiflora | Greene | Boraginaceae | 8 |
| Orobanche fasciculata | Nutt. | Orobanchaceae | 8 |
| Orobanche ludoviciana | Nutt. | Orobanchaceae | 8 |
| Orobanche uniflora | L. | Orobanchaceae | 8 |
| Orthilia secunda | (L.) House | Ericaceae | 8 |
| Orthocarpus luteus | Nutt. | Orobanchaceae | 8 |
| Osmorhiza claytonii | C.B.Clarke | Apiaceae | 8 |
| Osmorhiza longistylis | DC. | Apiaceae | 8 |
| Ostrya virginiana | (Mill.) K.Koch | Betulaceae | 8 |
| Oxalis dillenii | Jacq. | Oxalidaceae | 8 |
| Oxalis stricta | L. | Oxalidaceae | 8 |
| Oxalis violacea | L. | Oxalidaceae | 8 |
| Oxybaphus nyctagineus | (Michx.) Sweet | Nyctaginaceae | 8 |
| Oxytropis lambertii | Pursh | Fabaceae | 8 |
| Oxytropis multiceps | Nutt. | Fabaceae | 8 |
| Oxytropis sericea | Nutt. | Fabaceae | 8 |
| Packera cana | (Hook.) W.A.Weber & Á.Löve | Asteraceae | 8 |
| Packera glabella | (Poir.) C.Jeffrey | Asteraceae | 8 |
| Packera plattensis | (Nutt.) W.A.Weber & Á.Löve | Asteraceae | 8 |
| Packera pseudaurea | (Rydb.) W.A.Weber & Á.Löve | Asteraceae | 8 |
| Palafoxia sphacelata | (Nutt. ex Torr.) Cory | Asteraceae | 8 |
| Panax quinquefolius | L. | Araliaceae | 8 |
| Panicum capillare | L. | Poaceae | 8 |
| Panicum dichotomiflorum | Michx. | Poaceae | 8 |
| Panicum virgatum | L. | Poaceae | 8 |
| Parietaria pensylvanica | Muhl. ex Willd. | Urticaceae | 8 |
| Paronychia canadensis | (L.) Alph.Wood | Caryophyllaceae | 8 |
| Paronychia jamesii | Torr. & A.Gray | Caryophyllaceae | 8 |
| Paronychia sessiliflora | Nutt. | Caryophyllaceae | 8 |
| Parthenocissus quinquefolia | (L.) Planch. | Vitaceae | 8 |
| Paspalum setaceum | Michx. | Poaceae | 8 |
| Patis racemosa | (Sm.) Romasch., P.M.Peterson & Soreng | Poaceae | 8 |
| Pectis angustifolia | Torr. | Asteraceae | 8 |
| Pedicularis canadensis | L. | Orobanchaceae | 8 |
| Pedicularis crenulata | Benth. | Orobanchaceae | 8 |
| Pedicularis lanceolata | Michx. | Orobanchaceae | 8 |
| Pediomelum argophyllum | (Pursh) J.W.Grimes | Fabaceae | 8 |
| Pediomelum cuspidatum | (Pursh) Rydb. | Fabaceae | 8 |
| Pediomelum digitatum | (Nutt.) Isely | Fabaceae | 8 |
| Pediomelum esculentum | (Pursh) Rydb. | Fabaceae | 8 |
| Pediomelum hypogaeum | (Nutt.) Rydb. | Fabaceae | 8 |
| Pediomelum linearifolium | (Torr. & A.Gray) J.W.Grimes | Fabaceae | 8 |
| Pediomelum tenuiflorum | (Pursh) A.N.Egan | Fabaceae | 8 |
| Pelecyphora missouriensis | (Sweet) D.Aquino & Dan.Sánchez | Cactaceae | 8 |
| Pelecyphora vivipara | (Nutt.) D.Aquino & Dan.Sánchez | Cactaceae | 8 |
| Pellaea atropurpurea | (L.) Link | Pteridaceae | 8 |
| Pellaea glabella | Mett. | Pteridaceae | 8 |
| Penstemon albidus | Nutt. | Plantaginaceae | 8 |
| Penstemon ambiguus | Torr. | Plantaginaceae | 8 |
| Penstemon angustifolius | Nutt. ex Pursh | Plantaginaceae | 8 |
| Penstemon bradburyi | Pursh | Plantaginaceae | 8 |
| Penstemon buckleyi | Pennell | Plantaginaceae | 8 |
| Penstemon cobaea | Nutt. | Plantaginaceae | 8 |
| Penstemon digitalis | Nutt. ex Sims | Plantaginaceae | 8 |
| Penstemon eriantherus | Nutt. ex Pursh | Plantaginaceae | 8 |
| Penstemon glaber | Pursh | Plantaginaceae | 8 |
| Penstemon gracilis | Nutt. | Plantaginaceae | 8 |
| Penstemon tubaeflorus | Nutt. | Plantaginaceae | 8 |
| Penthorum sedoides | L. | Penthoraceae | 8 |
| Persicaria amphibia | (L.) Delarbre | Polygonaceae | 8 |
| Persicaria bicornis | (Raf.) Nieuwl. | Polygonaceae | 8 |
| Persicaria hydropiperoides | (Michx.) Small | Polygonaceae | 8 |
| Persicaria lapathifolia | (L.) Delarbre | Polygonaceae | 8 |
| Persicaria pensylvanica | (L.) M.Gómez | Polygonaceae | 8 |
| Persicaria punctata | Small | Polygonaceae | 8 |
| Persicaria sagittata | (L.) H.Gross | Polygonaceae | 8 |
| Persicaria virginiana | (L.) Gaertn. | Polygonaceae | 8 |
| Phacelia hastata | Douglas ex Lehm. | Hydrophyllaceae | 8 |
| Phalaris arundinacea | L. | Poaceae | 8 |
| Phemeranthus calcaricus | (S.Ware) Kiger | Montiaceae | 8 |
| Phemeranthus calycinus | (Engelm.) Kiger | Montiaceae | 8 |
| Phemeranthus parviflorus | (Nutt.) Kiger | Montiaceae | 8 |
| Phemeranthus rugospermus | (Holz.) Kiger | Montiaceae | 8 |
| Phlox alyssifolia | Greene | Polemoniaceae | 8 |
| Phlox andicola | (Britton) E.E.Nelson | Polemoniaceae | 8 |
| Phlox diffusa | Benth. | Polemoniaceae | 8 |
| Phlox divaricata | L. | Polemoniaceae | 8 |
| Phlox hoodii | Richardson | Polemoniaceae | 8 |
| Phlox paniculata | L. | Polemoniaceae | 8 |
| Phlox pilosa | L. | Polemoniaceae | 8 |
| Phragmites australis | (Cav.) Steud. | Poaceae | 8 |
| Phryma leptostachya | L. | Phrymaceae | 8 |
| Phyla cuneifolia | (Torr.) Greene | Verbenaceae | 8 |
| Phyla lanceolata | (Michx.) Greene | Verbenaceae | 8 |
| Physalis hederifolia | A.Gray | Solanaceae | 8 |
| Physalis heterophylla | Nees | Solanaceae | 8 |
| Physalis longifolia | Nutt. | Solanaceae | 8 |
| Physalis pumila | Nutt. | Solanaceae | 8 |
| Physalis virginiana | Mill. | Solanaceae | 8 |
| Physaria arenosa | (Richardson) O'Kane & Al-Shehbaz | Brassicaceae | 8 |
| Physaria ludoviciana | (Nutt.) O'Kane & Al-Shehbaz | Brassicaceae | 8 |
| Physaria montana | (A.Gray) Greene | Brassicaceae | 8 |
| Physaria ovalifolia | (Rydb.) O'Kane & Al-Shehbaz | Brassicaceae | 8 |
| Physaria spatulata | (Rydb.) Grady & O'Kane | Brassicaceae | 8 |
| Physocarpus intermedius | (Rydb.) C.K.Schneid. | Rosaceae | 8 |
| Physocarpus opulifolius | (L.) Maxim. | Rosaceae | 8 |
| Physostegia parviflora | Nutt. ex A.Gray | Lamiaceae | 8 |
| Physostegia virginiana | (L.) Benth. | Lamiaceae | 8 |
| Phytolacca americana | L. | Phytolaccaceae | 8 |
| Picradeniopsis oppositifolia | (Nutt.) Rydb. | Asteraceae | 8 |
| Pilea fontana | (Lunell) Rydb. | Urticaceae | 8 |
| Pilea pumila | A.Gray | Urticaceae | 8 |
| Pilularia americana | A.Br. | Marsileaceae | 8 |
| Pinus flexilis | E.James | Pinaceae | 8 |
| Pinus ponderosa | Douglas ex C.Lawson | Pinaceae | 8 |
| Piptatheropsis micrantha | (Trin. & Rupr.) Romasch., P.M.Peterson & Soreng | Poaceae | 8 |
| Plagiobothrys scouleri | (Hook. & Arn.) I.M.Johnst. | Boraginaceae | 8 |
| Plantago aristata | Michx. | Plantaginaceae | 8 |
| Plantago elongata | Pursh | Plantaginaceae | 8 |
| Plantago patagonica | Jacq. | Plantaginaceae | 8 |
| Plantago rhodosperma | Decne. | Plantaginaceae | 8 |
| Plantago rugelii | Decne. | Plantaginaceae | 8 |
| Plantago virginica | L. | Plantaginaceae | 8 |
| Platanthera aquilonis | Sheviak | Orchidaceae | 8 |
| Platanthera leucophaea | (Nutt.) Lindl. | Orchidaceae | 8 |
| Platanus occidentalis | L. | Platanaceae | 8 |
| Poa fendleriana | (Steud.) Vasey | Poaceae | 8 |
| Poa interior | Rydb. | Poaceae | 8 |
| Poa nemoralis | L. | Poaceae | 8 |
| Poa palustris | L. | Poaceae | 8 |
| Poa pratensis | L. | Poaceae | 8 |
| Poa secunda | J.Presl | Poaceae | 8 |
| Poa sylvestris | A.Gray | Poaceae | 8 |
| Podophyllum peltatum | L. | Berberidaceae | 8 |
| Polygala senega | L. | Polygalaceae | 8 |
| Polygonatum biflorum | (Walter) Elliott | Asparagaceae | 8 |
| Polygonum achoreum | S.F.Blake | Polygonaceae | 8 |
| Polygonum aviculare | L. | Polygonaceae | 8 |
| Polygonum tenue | Michx. | Polygonaceae | 8 |
| Polypogon interruptus | Kunth | Poaceae | 8 |
| Polytaenia nuttallii | DC. | Apiaceae | 8 |
| Pomaria jamesii | (Torr. & A.Gray) Walp. | Fabaceae | 8 |
| Pontederia cordata | L. | Pontederiaceae | 8 |
| Populus angustifolia | E.James | Salicaceae | 8 |
| Populus deltoides | W.Bartram ex Marshall | Salicaceae | 8 |
| Populus tremuloides | Michx. | Salicaceae | 8 |
| Potamogeton amplifolius | Tuck. | Potamogetonaceae | 8 |
| Potamogeton diversifolius | Raf. | Potamogetonaceae | 8 |
| Potamogeton foliosus | Raf. | Potamogetonaceae | 8 |
| Potamogeton friesii | Rupr. | Potamogetonaceae | 8 |
| Potamogeton gramineus | L. | Potamogetonaceae | 8 |
| Potamogeton illinoensis | Morong | Potamogetonaceae | 8 |
| Potamogeton natans | L. | Potamogetonaceae | 8 |
| Potamogeton nodosus | Poir. | Potamogetonaceae | 8 |
| Potamogeton praelongus | Wulfen | Potamogetonaceae | 8 |
| Potamogeton pusillus | L. | Potamogetonaceae | 8 |
| Potamogeton richardsonii | Rydb. | Potamogetonaceae | 8 |
| Potamogeton spirillus | Tuck. | Potamogetonaceae | 8 |
| Potamogeton strictifolius | A.Benn. | Potamogetonaceae | 8 |
| Potamogeton zosteriformis | Fernald | Potamogetonaceae | 8 |
| Potentilla effusa | Douglas ex Lehm. | Rosaceae | 8 |
| Potentilla hippiana | Lehm. | Rosaceae | 8 |
| Potentilla norvegica | L. | Rosaceae | 8 |
| Potentilla pensylvanica | L. | Rosaceae | 8 |
| Potentilla rivalis | Nutt. | Rosaceae | 8 |
| Potentilla simplex | Michx. | Rosaceae | 8 |
| Potentilla supina | L. | Rosaceae | 8 |
| Primula meadia | (L.) A.R.Mast & Reveal | Primulaceae | 8 |
| Primula pauciflora | (Greene) A.R.Mast & Reveal | Primulaceae | 8 |
| Proboscidea louisianica | (Mill.) Thell. | Martyniaceae | 8 |
| Prosartes trachycarpa | S.Watson | Liliaceae | 8 |
| Prunella vulgaris | L. | Lamiaceae | 8 |
| Prunus americana | Marshall | Rosaceae | 8 |
| Prunus angustifolia | Marshall | Rosaceae | 8 |
| Prunus pumila | L. | Rosaceae | 8 |
| Prunus serotina | Ehrh. | Rosaceae | 8 |
| Prunus virginiana | L. | Rosaceae | 8 |
| Pseudognaphalium stramineum | (Kunth) Anderb. | Asteraceae | 8 |
| Pseudoroegneria spicata | (Pursh) Á.Löve | Poaceae | 8 |
| Ptelea trifoliata | L. | Rutaceae | 8 |
| Pterospora andromedea | Nutt. | Ericaceae | 8 |
| Puccinellia nuttalliana | (Schult.) Hitchc. | Poaceae | 8 |
| Pulsatilla nuttalliana | (DC.) Spreng. | Ranunculaceae | 8 |
| Purshia tridentata | (Pursh) DC. | Rosaceae | 8 |
| Pycnanthemum tenuifolium | Schrad. | Lamiaceae | 8 |
| Pycnanthemum verticillatum | (Michx.) Pers. | Lamiaceae | 8 |
| Pycnanthemum virginianum | (L.) T.Durand & B.D.Jacks. ex B.L.Rob. & Fernald | Lamiaceae | 8 |
| Pyrola chlorantha | Sw. | Ericaceae | 8 |
| Pyrola elliptica | Nutt. | Ericaceae | 8 |
| Pyrrhopappus carolinianus | (Walter) DC. | Asteraceae | 8 |
| Quercus alba | L. | Fagaceae | 8 |
| Quercus macrocarpa | Michx. | Fagaceae | 8 |
| Quercus marilandica | (L.) Münchh. | Fagaceae | 8 |
| Quercus muehlenbergii | Engelm. | Fagaceae | 8 |
| Quercus rubra | L. | Fagaceae | 8 |
| Quercus shumardii | Buckley | Fagaceae | 8 |
| Quercus velutina | Lam. | Fagaceae | 8 |
| Ranunculus abortivus | L. | Ranunculaceae | 8 |
| Ranunculus carolinianus | DC. | Ranunculaceae | 8 |
| Ranunculus fascicularis | Muhl. ex Bigelow | Ranunculaceae | 8 |
| Ranunculus flabellaris | Raf. | Ranunculaceae | 8 |
| Ranunculus glaberrimus | Hook. | Ranunculaceae | 8 |
| Ranunculus inamoenus | Greene | Ranunculaceae | 8 |
| Ranunculus macounii | Britton | Ranunculaceae | 8 |
| Ranunculus minimus | E.H.L.Krause | Ranunculaceae | 8 |
| Ranunculus pensylvanicus | L.f. | Ranunculaceae | 8 |
| Ranunculus recurvatus | Poir. | Ranunculaceae | 8 |
| Ranunculus rhomboideus | Goldie | Ranunculaceae | 8 |
| Ranunculus sceleratus | L. | Ranunculaceae | 8 |
| Ranunculus trichophyllus | Chaix | Ranunculaceae | 8 |
| Ratibida columnifera | (Nutt.) Wooton & Standl. | Asteraceae | 8 |
| Ratibida pinnata | (Vent.) Barnhart | Asteraceae | 8 |
| Rhamnus lanceolata | Pursh | Rhamnaceae | 8 |
| Rhus aromatica | Aiton | Anacardiaceae | 8 |
| Rhus copallinum | L. | Anacardiaceae | 8 |
| Rhus glabra | L. | Anacardiaceae | 8 |
| Ribes americanum | Mill. | Grossulariaceae | 8 |
| Ribes aureum | Pursh | Grossulariaceae | 8 |
| Ribes cereum | Douglas | Grossulariaceae | 8 |
| Ribes hirtellum | Michx. | Grossulariaceae | 8 |
| Ribes missouriense | Nutt. | Grossulariaceae | 8 |
| Ribes oxyacanthoides | L. | Grossulariaceae | 8 |
| Rorippa curvipes | Greene | Brassicaceae | 8 |
| Rorippa palustris | (L.) Besser | Brassicaceae | 8 |
| Rorippa sessiliflora | (Nutt.) Hitchc. | Brassicaceae | 8 |
| Rosa arkansana | Porter | Rosaceae | 8 |
| Rosa blanda | Aiton | Rosaceae | 8 |
| Rosa carolina | L. | Rosaceae | 8 |
| Rosa setigera | Michx. | Rosaceae | 8 |
| Rosa woodsii | Lindl. | Rosaceae | 8 |
| Rotala ramosior | (L.) Koehne | Lythraceae | 8 |
| Rubus allegheniensis | Porter | Rosaceae | 8 |
| Rubus flagellaris | Willd. | Rosaceae | 8 |
| Rubus idaeus | L. | Rosaceae | 8 |
| Rubus occidentalis | L. | Rosaceae | 8 |
| Rubus pubescens | Raf. | Rosaceae | 8 |
| Rudbeckia hirta | L. | Asteraceae | 8 |
| Rudbeckia laciniata | L. | Asteraceae | 8 |
| Rudbeckia triloba | L. | Asteraceae | 8 |
| Ruellia humilis | Nutt. | Acanthaceae | 8 |
| Ruellia strepens | L. | Acanthaceae | 8 |
| Rumex altissimus | Alph.Wood | Polygonaceae | 8 |
| Rumex britannica | L. | Polygonaceae | 8 |
| Rumex maritimus | L. | Polygonaceae | 8 |
| Rumex triangulivalvis | (Danser) Rech.f. | Polygonaceae | 8 |
| Rumex venosus | Pursh | Polygonaceae | 8 |
| Rumex verticillatus | L. | Polygonaceae | 8 |
| Ruppia cirrhosa | (Petagna) Grande | Ruppiaceae | 8 |
| Sabulina michauxii | (Fenzl) Dillenb. & Kadereit | Caryophyllaceae | 8 |
| Sagittaria brevirostra | Mack. & Bush | Alismataceae | 8 |
| Sagittaria cristata | Engelm. | Alismataceae | 8 |
| Sagittaria cuneata | E.Sheld. | Alismataceae | 8 |
| Sagittaria graminea | Michx. | Alismataceae | 8 |
| Sagittaria latifolia | Willd. | Alismataceae | 8 |
| Sagittaria longiloba | Engelm. ex J.G.Sm. | Alismataceae | 8 |
| Sagittaria montevidensis | Cham. & Schltdl. | Alismataceae | 8 |
| Sagittaria rigida | Pursh | Alismataceae | 8 |
| Salicornia rubra | A.Nelson | Chenopodiaceae | 8 |
| Salix amygdaloides | Andersson | Salicaceae | 8 |
| Salix bebbiana | Sarg. | Salicaceae | 8 |
| Salix eriocephala | Michx. | Salicaceae | 8 |
| Salix exigua | Nutt. | Salicaceae | 8 |
| Salix humilis | Marshall | Salicaceae | 8 |
| Salix interior | Rowlee | Salicaceae | 8 |
| Salix nigra | Marshall | Salicaceae | 8 |
| Salix petiolaris | Sm. | Salicaceae | 8 |
| Salvia azurea | Lam. ex Vahl | Lamiaceae | 8 |
| Salvia reflexa | Hornem. | Lamiaceae | 8 |
| Sambucus canadensis | L. | Viburnaceae | 8 |
| Sanguinaria canadensis | L. | Papaveraceae | 8 |
| Sanicula canadensis | L. | Apiaceae | 8 |
| Sanicula marilandica | L. | Apiaceae | 8 |
| Sanicula odorata | (Raf.) K.M.Pryer & L.R.Phillippe | Apiaceae | 8 |
| Sarcobatus vermiculatus | (Hook.) Torr. | Sarcobataceae | 8 |
| Schizachne purpurascens | (Torr.) Swallen | Poaceae | 8 |
| Schizachyrium scoparium | (Michx.) Nash | Poaceae | 8 |
| Schoenoplectus acutus | (Muhl. ex Bigelow) Á.Löve & D.Löve | Cyperaceae | 8 |
| Schoenoplectus heterochaetus | (Chase) Soják | Cyperaceae | 8 |
| Schoenoplectus pungens | (Vahl) Palla | Cyperaceae | 8 |
| Schoenoplectus tabernaemontani | (C.C.Gmel.) Palla | Cyperaceae | 8 |
| Scirpus atrovirens | Willd. | Cyperaceae | 8 |
| Scirpus georgianus | R.M.Harper | Cyperaceae | 8 |
| Scirpus microcarpus | J.Presl & C.Presl | Cyperaceae | 8 |
| Scirpus pendulus | Muhl. | Cyperaceae | 8 |
| Scleria triglomerata | Michx. | Cyperaceae | 8 |
| Scrophularia lanceolata | Pursh | Scrophulariaceae | 8 |
| Scrophularia marilandica | L. | Scrophulariaceae | 8 |
| Scutellaria brittonii | Porter | Lamiaceae | 8 |
| Scutellaria galericulata | L. | Lamiaceae | 8 |
| Scutellaria lateriflora | L. | Lamiaceae | 8 |
| Scutellaria parvula | Michx. | Lamiaceae | 8 |
| Sedum lanceolatum | Torr. | Crassulaceae | 8 |
| Selaginella rupestris | (L.) Spring | Selaginellaceae | 8 |
| Senecio integerrimus | Nutt. | Asteraceae | 8 |
| Senecio spartioides | Torr. & A.Gray | Asteraceae | 8 |
| Senna marilandica | (L.) Link | Fabaceae | 8 |
| Shepherdia argentea | (Pursh) Nutt. | Elaeagnaceae | 8 |
| Sicyos angulatus | L. | Cucurbitaceae | 8 |
| Silene antirrhina | L. | Caryophyllaceae | 8 |
| Silene drummondii | Hook. | Caryophyllaceae | 8 |
| Silene menziesii | Hook. | Caryophyllaceae | 8 |
| Silene stellata | W.T.Aiton | Caryophyllaceae | 8 |
| Silphium integrifolium | Michx. | Asteraceae | 8 |
| Silphium laciniatum | L. | Asteraceae | 8 |
| Silphium perfoliatum | L. | Asteraceae | 8 |
| Silphium terebinthinaceum | Jacq. | Asteraceae | 8 |
| Sisyrinchium angustifolium | Mill. | Iridaceae | 8 |
| Sisyrinchium campestre | E.P.Bicknell | Iridaceae | 8 |
| Sisyrinchium montanum | Greene | Iridaceae | 8 |
| Sisyrinchium pruinosum | E.P.Bicknell | Iridaceae | 8 |
| Sium suave | Walter | Apiaceae | 8 |
| Smilax ecirrhata | (Engelm. ex Kunth) S.Watson | Smilacaceae | 8 |
| Smilax pulverulenta | Michx. | Smilacaceae | 8 |
| Smilax tamnoides | L. | Smilacaceae | 8 |
| Solanum carolinense | L. | Solanaceae | 8 |
| Solanum emulans | Raf. | Solanaceae | 8 |
| Solanum rostratum | Dunal | Solanaceae | 8 |
| Solanum triflorum | Nutt. | Solanaceae | 8 |
| Solidago altissima | L. | Asteraceae | 8 |
| Solidago canadensis | L. | Asteraceae | 8 |
| Solidago flexicaulis | L. | Asteraceae | 8 |
| Solidago gigantea | Aiton | Asteraceae | 8 |
| Solidago missouriensis | Nutt. | Asteraceae | 8 |
| Solidago nemoralis | Aiton | Asteraceae | 8 |
| Solidago petiolaris | Aiton | Asteraceae | 8 |
| Solidago rigida | L. | Asteraceae | 8 |
| Solidago rigidiuscula | (Torr. & A.Gray) Porter | Asteraceae | 8 |
| Solidago ulmifolia | Muhl. ex Willd. | Asteraceae | 8 |
| Sophora nuttalliana | B.L.Turner | Fabaceae | 8 |
| Sorghastrum nutans | (L.) Nash | Poaceae | 8 |
| Sparganium emersum | Rehmann | Typhaceae | 8 |
| Sparganium eurycarpum | Engelm. | Typhaceae | 8 |
| Spergularia marina | (L.) Besser | Caryophyllaceae | 8 |
| Spermolepis inermis | (Nutt. ex DC.) Mathias & Constance | Apiaceae | 8 |
| Sphaeralcea coccinea | (Nutt.) Rydb. | Malvaceae | 8 |
| Sphenopholis intermedia | (Rydb.) Rydb. | Poaceae | 8 |
| Sphenopholis obtusata | (Michx.) Scribn. | Poaceae | 8 |
| Spiranthes diluvialis | Sheviak | Orchidaceae | 8 |
| Spiranthes incurva | (Jenn.) M.C.Pace | Orchidaceae | 8 |
| Spiranthes lucida | (H.H.Eaton) Ames | Orchidaceae | 8 |
| Spiranthes magnicamporum | Sheviak | Orchidaceae | 8 |
| Spiranthes romanzoffiana | Cham. | Orchidaceae | 8 |
| Spiranthes vernalis | Engelm. & A.Gray | Orchidaceae | 8 |
| Spirodela polyrhiza | (L.) Schleid. | Araceae | 8 |
| Sporobolus airoides | (Torr.) Torr. | Poaceae | 8 |
| Sporobolus compositus | (Poir.) Merr. | Poaceae | 8 |
| Sporobolus cryptandrus | (Torr.) A.Gray | Poaceae | 8 |
| Sporobolus heterolepis | (A.Gray) A.Gray | Poaceae | 8 |
| Sporobolus hookerianus | P.M.Peterson & Saarela | Poaceae | 8 |
| Sporobolus michauxianus | (Hitchc.) P.M.Peterson & Saarela | Poaceae | 8 |
| Sporobolus neglectus | Nash | Poaceae | 8 |
| Sporobolus pyramidatus | (Lam.) Hitchc. | Poaceae | 8 |
| Sporobolus rigidus | (Buckley) P.M.Peterson | Poaceae | 8 |
| Sporobolus vaginiflorus | (Torr. ex A.Gray) Alph.Wood | Poaceae | 8 |
| Stachys pilosa | Nutt. | Lamiaceae | 8 |
| Stachys tenuifolia | Willd. | Lamiaceae | 8 |
| Staphylea trifolia | L. | Staphyleaceae | 8 |
| Stellaria longifolia | Muhl. ex Willd. | Caryophyllaceae | 8 |
| Stellaria pubera | Michx. | Caryophyllaceae | 8 |
| Stenaria nigricans | (Lam.) Terrell | Rubiaceae | 8 |
| Stenotus armerioides | Nutt. | Asteraceae | 8 |
| Stephanomeria runcinata | Nutt. | Asteraceae | 8 |
| Stuckenia filiformis | (Pers.) Börner | Potamogetonaceae | 8 |
| Stuckenia pectinata | (L.) Börner | Potamogetonaceae | 8 |
| Suaeda calceoliformis | (Hook.) Moq. | Chenopodiaceae | 8 |
| Symphoricarpos albus | (L.) S.F.Blake | Caprifoliaceae | 8 |
| Symphoricarpos occidentalis | (R.Br.) Hook. | Caprifoliaceae | 8 |
| Symphoricarpos orbiculatus | Moench | Caprifoliaceae | 8 |
| Symphyotrichum boreale | (Torr. & A.Gray) Á.Löve & D.Löve | Asteraceae | 8 |
| Symphyotrichum ciliatum | (Ledeb.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum cordifolium | (L.) 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 fendleri | (A.Gray) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum firmum | (Nees) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum laeve | (L.) Á.Löve & D.Löve | Asteraceae | 8 |
| Symphyotrichum lanceolatum | (Willd.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum novae-angliae | (L.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum oblongifolium | (Nutt.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum ontarionis | (Wiegand) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum pilosum | (Willd.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum praealtum | (Poir.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum sericeum | (Vent.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum turbinellum | (Lindl.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum urophyllum | (Lindl.) G.L.Nesom | Asteraceae | 8 |
| Tetraneuris acaulis | Greene | Asteraceae | 8 |
| Tetraneuris scaposa | (DC.) Greene | Asteraceae | 8 |
| Teucrium canadense | L. | Lamiaceae | 8 |
| Thalictrum dasycarpum | Fisch., C.A.Mey. & Avé-Lall. | Ranunculaceae | 8 |
| Thalictrum dioicum | L. | Ranunculaceae | 8 |
| Thalictrum venulosum | Trel. | Ranunculaceae | 8 |
| Thelesperma filifolium | (Hook.) A.Gray | Asteraceae | 8 |
| Thelesperma megapotamicum | (Spreng.) Kuntze | Asteraceae | 8 |
| Thelypodium integrifolium | (Nutt.) Endl. | Brassicaceae | 8 |
| Thelypteris palustris | Schott | Thelypteridaceae | 8 |
| Thermopsis rhombifolia | (Pursh) Richardson | Fabaceae | 8 |
| Tilia americana | L. | Malvaceae | 8 |
| Tomostima cuneifolia | (Nutt. ex Torr. & A.Gray) Al-Shehbaz, M.Koch & Jordon-Thaden | Brassicaceae | 8 |
| Tomostima reptans | (Lam.) Al-Shehbaz, M.Koch & Jordon-Thaden | Brassicaceae | 8 |
| Townsendia exscapa | (Richardson) Porter | Asteraceae | 8 |
| Townsendia grandiflora | Nutt. | Asteraceae | 8 |
| Townsendia hookeri | Beaman | Asteraceae | 8 |
| Toxicodendron radicans | (L.) Kuntze | Anacardiaceae | 8 |
| Toxicoscordion venenosum | (S.Watson) Rydb. | Melanthiaceae | 8 |
| Tradescantia bracteata | Small | Commelinaceae | 8 |
| Tradescantia occidentalis | (Britton) Smyth | Commelinaceae | 8 |
| Tradescantia ohiensis | Raf. | Commelinaceae | 8 |
| Tragia ramosa | Torr. | Euphorbiaceae | 8 |
| Trichogalium boreale | (L.) Fourr. | Rubiaceae | 8 |
| Tridens flavus | (L.) Hitchc. | Poaceae | 8 |
| Trifolium reflexum | L. | Fabaceae | 8 |
| Triglochin maritima | L. | Juncaginaceae | 8 |
| Triglochin palustris | L. | Juncaginaceae | 8 |
| Trillium nivale | Riddell | Melanthiaceae | 8 |
| Triodanis holzingeri | McVaugh | Campanulaceae | 8 |
| Triodanis leptocarpa | Nieuwl. | Campanulaceae | 8 |
| Triodanis perfoliata | (L.) Nieuwl. | Campanulaceae | 8 |
| Triosteum aurantiacum | E.P.Bicknell | Caprifoliaceae | 8 |
| Triosteum perfoliatum | L. | Caprifoliaceae | 8 |
| Triphora trianthophoros | (Sw.) Rydb. | Orchidaceae | 8 |
| Triplasis purpurea | (Walter) Chapm. | Poaceae | 8 |
| Tripsacum dactyloides | (L.) L. | Poaceae | 8 |
| Turritis glabra | L. | Brassicaceae | 8 |
| Typha angustifolia | L. | Typhaceae | 8 |
| Typha domingensis | Pers. | Typhaceae | 8 |
| Typha latifolia | L. | Typhaceae | 8 |
| Ulmus americana | L. | Ulmaceae | 8 |
| Ulmus rubra | Muhl. | Ulmaceae | 8 |
| Ulmus thomasii | Sarg. | Ulmaceae | 8 |
| Urtica gracilis | Aiton | Urticaceae | 8 |
| Utricularia macrorhiza | Leconte | Lentibulariaceae | 8 |
| Utricularia minor | L. | Lentibulariaceae | 8 |
| Verbena bipinnatifida | (Nutt.) Schauer | Verbenaceae | 8 |
| Verbena bracteata | Cav. ex Lag. & Rodr. | Verbenaceae | 8 |
| Verbena canadensis | (L.) Britton | Verbenaceae | 8 |
| Verbena hastata | L. | Verbenaceae | 8 |
| Verbena simplex | Lehm. | Verbenaceae | 8 |
| Verbena stricta | Vent. | Verbenaceae | 8 |
| Verbena urticifolia | L. | Verbenaceae | 8 |
| Verbesina alternifolia | (L.) Britton ex Kearney | Asteraceae | 8 |
| Vernonia baldwinii | Torr. | Asteraceae | 8 |
| Vernonia fasciculata | Michx. | Asteraceae | 8 |
| Vernonia gigantea | (Walter) Trel. | Asteraceae | 8 |
| Veronica americana | (Raf.) Schwein. ex Benth. | Plantaginaceae | 8 |
| Veronica catenata | Pennell | Plantaginaceae | 8 |
| Veronica peregrina | L. | Plantaginaceae | 8 |
| Veronica wyomingensis | (A.Nelson) M.M.Mart.Ort. & Albach | Plantaginaceae | 8 |
| Veronicastrum virginicum | (L.) Farw. | Plantaginaceae | 8 |
| Vesper montanus | (Torr. & A.Gray) R.L.Hartm. & G.L.Nesom | Apiaceae | 8 |
| Viburnum lentago | L. | Viburnaceae | 8 |
| Viburnum opulus | L. | Viburnaceae | 8 |
| Vicia americana | Muhl. ex Willd. | Fabaceae | 8 |
| Viola adunca | Sm. | Violaceae | 8 |
| Viola canadensis | L. | Violaceae | 8 |
| Viola lanceolata | L. | Violaceae | 8 |
| Viola missouriensis | Greene | Violaceae | 8 |
| Viola nephrophylla | Greene | Violaceae | 8 |
| Viola nuttallii | Pursh | Violaceae | 8 |
| Viola palmata | L. | Violaceae | 8 |
| Viola pedata | L. | Violaceae | 8 |
| Viola pedatifida | G.Don | Violaceae | 8 |
| Viola pubescens | Aiton | Violaceae | 8 |
| Viola rafinesquei | Greene | Violaceae | 8 |
| Viola sororia | Willd. | Violaceae | 8 |
| Viola striata | Aiton | Violaceae | 8 |
| Vitis aestivalis | Michx. | Vitaceae | 8 |
| Vitis cinerea | (Engelm.) Millardet | Vitaceae | 8 |
| Vitis riparia | Michx. | Vitaceae | 8 |
| Vitis vulpina | L. | Vitaceae | 8 |
| Wolffia borealis | (Engelm.) Landolt | Araceae | 8 |
| Wolffia brasiliensis | Wedd. | Araceae | 8 |
| Wolffia columbiana | H.Karst. | Araceae | 8 |
| Woodsia obtusa | (Sw.) Torr. | Woodsiaceae | 8 |
| Woodsia oregana | D.C.Eaton | Woodsiaceae | 8 |
| Xanthisma grindelioides | (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 |
| Xanthium strumarium | L. | Asteraceae | 8 |
| Yucca glauca | Nutt. | Asparagaceae | 8 |
| Zannichellia palustris | L. | Potamogetonaceae | 8 |
| Zanthoxylum americanum | Mill. | Rutaceae | 8 |
| Zizania aquatica | L. | Poaceae | 8 |
| Zizania palustris | L. | Poaceae | 8 |
| Allium perdulce | S.V.Fraser | Amaryllidaceae | 7 |
| Bromus marginatus | Nees ex Steud. | Poaceae | 7 |
| Corispermum americanum | (Nutt.) Nutt. | Chenopodiaceae | 7 |
| Crepis runcinata | (E.James) Torr. & A.Gray | Asteraceae | 7 |
| Didiplis diandra | (Nutt. ex DC.) Alph.Wood | Lythraceae | 7 |
| Festuca saximontana | Rydb. | Poaceae | 7 |
| Isoetes melanopoda | J.Gay & Durieu | Isoetaceae | 7 |
| Plantago eriopoda | Torr. | Plantaginaceae | 7 |
| Scirpus pallidus | (Britton) Fernald | Cyperaceae | 7 |
| Senecio riddellii | Torr. & A.Gray | Asteraceae | 7 |
| Amaranthus arenicola | I.M.Johnst. | Amaranthaceae | 6 |
| Aristida basiramea | Vasey | Poaceae | 6 |
| Bacopa rotundifolia | (Michx.) Wettst. | Plantaginaceae | 6 |
| Calystegia macounii | (Greene) Brummitt | Convolvulaceae | 6 |
| Eragrostis capillaris | (L.) Nees | Poaceae | 6 |
| Muhlenbergia sobolifera | (Muhl. ex Willd.) Trin. | Poaceae | 6 |
| Physalis missouriensis | Mack. & Bush | Solanaceae | 6 |
| Platanthera praeclara | Sheviak & M.L.Bowles | Orchidaceae | 6 |
| Polygonum ramosissimum | Michx. | Polygonaceae | 6 |
| Scolochloa festucacea | (Willd.) Link | Poaceae | 6 |
| Asclepias lanuginosa | Nutt. | Apocynaceae | 5 |
| Cleomella angustifolia | Torr. | Cleomaceae | 5 |
| Bouteloua simplex | Lag. | Poaceae | 4 |
| Carex laeviconica | Dewey | Cyperaceae | 4 |
| Carex oligocarpa | Willd. | Cyperaceae | 4 |
| Cyperus hemidrummondii | Goetgh. | Cyperaceae | 4 |
| Erigeron canus | A.Gray | Asteraceae | 4 |
| Heteranthera rotundifolia | (Kunth) Griseb. | Pontederiaceae | 4 |
| Lechea stricta | Legg. ex Britton | Cistaceae | 4 |
| Lepidium ramosissimum | A.Nelson | Brassicaceae | 4 |
| Ludwigia polycarpa | Short & R.Peter | Onagraceae | 4 |
| Schoenoplectiella hallii | (A.Gray) Lye | Cyperaceae | 4 |
| Solidago mollis | Bartl. | Asteraceae | 4 |
| Carex echinodes | (Fernald) P.Rothr., Reznicek & Hipp | Cyperaceae | 3 |
| Carex mesochorea | Mack. | Cyperaceae | 3 |
| Carex missouriensis | P.Rothr. & Reznicek | Cyperaceae | 3 |
| Chenopodium cycloides | A.Nelson | Chenopodiaceae | 3 |
| Chenopodium desiccatum | A.Nelson | Chenopodiaceae | 3 |
| Erigeron subtrinervis | Rydb. ex Porter & Britton | Asteraceae | 3 |
| Eriocoma robusta | (Vasey) Romasch. | Poaceae | 3 |
| Pyrrocoma lanceolata | (Hook.) Greene | Asteraceae | 3 |