| Abdra brachycarpa | Greene | Brassicaceae | 8 |
| Abies amabilis | Douglas ex J.Forbes | Pinaceae | 8 |
| Abies concolor | (Gordon) Lindl. ex Hildebr. | Pinaceae | 8 |
| Abies grandis | (Douglas ex D.Don) Lindl. | Pinaceae | 8 |
| Abies lasiocarpa | (Hook.) Nutt. | Pinaceae | 8 |
| Abies magnifica | A.Murray bis | Pinaceae | 8 |
| Abies procera | Rehder | Pinaceae | 8 |
| Abronia latifolia | Eschsch. | Nyctaginaceae | 8 |
| Abronia mellifera | Douglas ex Hook. | Nyctaginaceae | 8 |
| Abronia turbinata | Torr. ex S.Watson | Nyctaginaceae | 8 |
| Abronia umbellata | Lam. | Nyctaginaceae | 8 |
| Acer circinatum | Pursh | Sapindaceae | 8 |
| Acer glabrum | Torr. | Sapindaceae | 8 |
| Acer macrophyllum | Pursh | Sapindaceae | 8 |
| Acer negundo | L. | Sapindaceae | 8 |
| Achillea millefolium | L. | Asteraceae | 8 |
| Achlys californica | Fukuda & H.Baker | Berberidaceae | 8 |
| Achlys triphylla | DC. | Berberidaceae | 8 |
| Achyrachaena mollis | Schauer | Asteraceae | 8 |
| Acmispon americanus | (Nutt.) Rydb. | Fabaceae | 8 |
| Acmispon brachycarpus | (Benth.) D.D.Sokoloff | Fabaceae | 8 |
| Acmispon grandiflorus | (Benth.) Brouillet | Fabaceae | 8 |
| Acmispon parviflorus | (Benth.) D.D.Sokoloff | Fabaceae | 8 |
| Acmispon wrangelianus | (Fisch. & C.A.Mey.) Sokoloff | Fabaceae | 8 |
| Aconitum columbianum | Nutt. | Ranunculaceae | 8 |
| Actaea elata | (Nutt.) Prantl | Ranunculaceae | 8 |
| Actaea rubra | (Aiton) Willd. | Ranunculaceae | 8 |
| Adelinia grandis | (Douglas ex Lehm.) J.I.Cohen | Boraginaceae | 8 |
| Adenocaulon bicolor | Hook. | Asteraceae | 8 |
| Adiantum aleuticum | (Rupr.) C.A.Paris | Pteridaceae | 8 |
| Adiantum jordanii | C.H.Mull. | Pteridaceae | 8 |
| Agastache urticifolia | (Benth.) Kuntze | Lamiaceae | 8 |
| Ageratina occidentalis | (Hook.) R.M.King & H.Rob. | Asteraceae | 8 |
| Agoseris apargioides | (Less.) Greene | Asteraceae | 8 |
| Agoseris aurantiaca | (Hook.) Greene | Asteraceae | 8 |
| Agoseris glauca | (Pursh) Raf. | Asteraceae | 8 |
| Agoseris grandiflora | (Nutt.) Greene | Asteraceae | 8 |
| Agoseris heterophylla | (Nutt.) Greene | Asteraceae | 8 |
| Agoseris retrorsa | Greene | Asteraceae | 8 |
| Agrimonia gryposepala | Wallr. | Rosaceae | 8 |
| Agrostis pallens | Trin. | Poaceae | 8 |
| Agrostis perennans | (Walter) Tuck. | Poaceae | 8 |
| Agrostis scabra | Willd. | Poaceae | 8 |
| Alchemilla occidentalis | Nutt. | Rosaceae | 8 |
| Aliciella leptomeria | (A.Gray) J.M.Porter | Polemoniaceae | 8 |
| Aliciella lottiae | (A.G.Day) J.M.Porter | Polemoniaceae | 8 |
| Aliciella triodon | (Eastw.) Brand | Polemoniaceae | 8 |
| Alisma gramineum | Lej. | Alismataceae | 8 |
| Alisma triviale | Pursh | Alismataceae | 8 |
| Allenrolfea occidentalis | (S.Watson) Kuntze | Chenopodiaceae | 8 |
| Allium acuminatum | Hook. | Amaryllidaceae | 8 |
| Allium amplectens | Torr. | Amaryllidaceae | 8 |
| Allium anceps | Kellogg | Amaryllidaceae | 8 |
| Allium bisceptrum | S.Watson | Amaryllidaceae | 8 |
| Allium bolanderi | S.Watson | Amaryllidaceae | 8 |
| Allium brandegeei | S.Watson | Amaryllidaceae | 8 |
| Allium campanulatum | S.Watson | Amaryllidaceae | 8 |
| Allium cernuum | Roth | Amaryllidaceae | 8 |
| Allium crenulatum | Wiegand | Amaryllidaceae | 8 |
| Allium falcifolium | Hook. & Arn. | Amaryllidaceae | 8 |
| Allium fibrillum | M.E.Jones | Amaryllidaceae | 8 |
| Allium geyeri | S.Watson | Amaryllidaceae | 8 |
| Allium lemmonii | S.Watson | Amaryllidaceae | 8 |
| Allium macrum | S.Watson | Amaryllidaceae | 8 |
| Allium nevadense | S.Watson | Amaryllidaceae | 8 |
| Allium nevii | S.Watson | Amaryllidaceae | 8 |
| Allium parvum | Kellogg | Amaryllidaceae | 8 |
| Allium peninsulare | Lemmon ex Greene | Amaryllidaceae | 8 |
| Allium platycaule | S.Watson | Amaryllidaceae | 8 |
| Allium robinsonii | L.F.Hend. | Amaryllidaceae | 8 |
| Allium schoenoprasum | L. | Amaryllidaceae | 8 |
| Allium siskiyouense | Ownbey ex Traub | Amaryllidaceae | 8 |
| Allium unifolium | Kellogg | Amaryllidaceae | 8 |
| Allium validum | S.Watson | Amaryllidaceae | 8 |
| Allophyllum gilioides | (Benth.) A.D.Grant & V.E.Grant | Polemoniaceae | 8 |
| Allotropa virgata | Torr. & A.Gray | Ericaceae | 8 |
| Alnus alnobetula | (Ehrh.) K.Koch | Betulaceae | 8 |
| Alnus incana | (L.) Moench | Betulaceae | 8 |
| Alnus rhombifolia | Nutt. | Betulaceae | 8 |
| Alnus rubra | Bong. | Betulaceae | 8 |
| Alopecurus aequalis | Sobol. | Poaceae | 8 |
| Alopecurus carolinianus | Walter | Poaceae | 8 |
| Alopecurus saccatus | Vasey | Poaceae | 8 |
| Amauropelta nevadensis | (Baker) S.E.Fawc. & A.R.Sm. | Thelypteridaceae | 8 |
| Ambrosia acanthicarpa | Hook. | Asteraceae | 8 |
| Ambrosia artemisiifolia | L. | Asteraceae | 8 |
| Ambrosia chamissonis | Greene | Asteraceae | 8 |
| Ambrosia psilostachya | DC. | Asteraceae | 8 |
| Ambrosia trifida | L. | Asteraceae | 8 |
| Amelanchier alnifolia | (Nutt.) Nutt. ex M.Roem. | Rosaceae | 8 |
| Amelanchier cusickii | Fernald | Rosaceae | 8 |
| Amelanchier utahensis | Koehne | Rosaceae | 8 |
| Ammannia robusta | Heer & Regel | Lythraceae | 8 |
| Amorpha fruticosa | L. | Fabaceae | 8 |
| Amphiscirpus nevadensis | (S.Watson) Oteng-Yeb. | Cyperaceae | 8 |
| Amsinckia carinata | A.Nelson & J.F.Macbr. | Boraginaceae | 8 |
| Amsinckia lycopsoides | Lindl. ex Lehm. | Boraginaceae | 8 |
| Amsinckia menziesii | (Lehm.) A.Nelson & J.F.Macbr. | Boraginaceae | 8 |
| Amsinckia spectabilis | Fisch. & C.A.Mey. | Boraginaceae | 8 |
| Amsinckia tessellata | A.Gray | Boraginaceae | 8 |
| Anaphalis margaritacea | (L.) Benth. & Hook.f. | Asteraceae | 8 |
| Ancistrocarphus filagineus | A.Gray | Asteraceae | 8 |
| Andersonglossum occidentale | (A.Gray) J.I.Cohen | Boraginaceae | 8 |
| Androsace elongata | L. | Primulaceae | 8 |
| Androsace filiformis | Retz. | Primulaceae | 8 |
| Androsace laevigata | (A.Gray) Wendelbo | Primulaceae | 8 |
| Androsace septentrionalis | L. | Primulaceae | 8 |
| Anemonastrum deltoideum | (Hook.) Mosyakin | Ranunculaceae | 8 |
| Anemone drummondii | S.Watson | Ranunculaceae | 8 |
| Anemone multifida | Poir. | Ranunculaceae | 8 |
| Anemone parviflora | Michx. | Ranunculaceae | 8 |
| Anemonoides grayi | (Behr. & Kellogg) Starod. | Ranunculaceae | 8 |
| Anemonoides piperi | (Rydb.) Holub | Ranunculaceae | 8 |
| Anemopsis californica | (Nutt.) Hook. & Arn. | Saururaceae | 8 |
| Angelica arguta | Nutt. | Apiaceae | 8 |
| Angelica capitellata | (A.Gray) Spalik, Reduron & S.R.Downie | Apiaceae | 8 |
| Angelica genuflexa | Nutt. | Apiaceae | 8 |
| Angelica hendersonii | J.M.Coult. & Rose | Apiaceae | 8 |
| Angelica lucida | L. | Apiaceae | 8 |
| Angelica tomentosa | S.Watson | Apiaceae | 8 |
| Anisocarpus madioides | Nutt. | Asteraceae | 8 |
| Antennaria anaphaloides | Rydb. | Asteraceae | 8 |
| Antennaria argentea | Benth. | Asteraceae | 8 |
| Antennaria dimorpha | Torr. & A.Gray | Asteraceae | 8 |
| Antennaria geyeri | A.Gray | Asteraceae | 8 |
| Antennaria howellii | Greene | Asteraceae | 8 |
| Antennaria lanata | Greene | Asteraceae | 8 |
| Antennaria luzuloides | Torr. & A.Gray | Asteraceae | 8 |
| Antennaria media | Greene | Asteraceae | 8 |
| Antennaria microphylla | Rydb. | Asteraceae | 8 |
| Antennaria parvifolia | Nutt. | Asteraceae | 8 |
| Antennaria racemosa | Hook. | Asteraceae | 8 |
| Antennaria rosea | Greene | Asteraceae | 8 |
| Antennaria stenophylla | (A.Gray) A.Gray | Asteraceae | 8 |
| Antennaria umbrinella | Rydb. | Asteraceae | 8 |
| Anthoxanthum nitens | (Weber) Y.Schouten & Veldkamp | Poaceae | 8 |
| Anthoxanthum occidentale | (Buckley) Veldkamp | Poaceae | 8 |
| Anticlea elegans | (Pursh) Rydb. | Melanthiaceae | 8 |
| Anticlea occidentalis | (A.Gray) Zomlefer & Judd | Melanthiaceae | 8 |
| Apocynum androsaemifolium | L. | Apocynaceae | 8 |
| Apocynum cannabinum | L. | Apocynaceae | 8 |
| Aquilegia flavescens | S.Watson | Ranunculaceae | 8 |
| Aquilegia formosa | Fisch. ex DC. | Ranunculaceae | 8 |
| Arabis aculeolata | Greene | Brassicaceae | 8 |
| Arabis eschscholtziana | Andrz. ex Ledeb. | Brassicaceae | 8 |
| Aralia californica | S.Watson | Araliaceae | 8 |
| Arbutus menziesii | Pursh | Ericaceae | 8 |
| Arceuthobium americanum | Nutt. ex Engelm. | Santalaceae | 8 |
| Arceuthobium campylopodum | Engelm. | Santalaceae | 8 |
| Arceuthobium douglasii | Engelm. | Santalaceae | 8 |
| Arceuthobium siskiyouense | Hawksw., Wiens & Nickrent | Santalaceae | 8 |
| Arctostaphylos canescens | Eastw. | Ericaceae | 8 |
| Arctostaphylos columbiana | Piper | Ericaceae | 8 |
| Arctostaphylos glandulosa | Eastw. | Ericaceae | 8 |
| Arctostaphylos hispidula | Howell | Ericaceae | 8 |
| Arctostaphylos nevadensis | A.Gray | Ericaceae | 8 |
| Arctostaphylos patula | Greene | Ericaceae | 8 |
| Arctostaphylos uva-ursi | (L.) Spreng. | Ericaceae | 8 |
| Arctostaphylos viscida | Parry | Ericaceae | 8 |
| Argemone munita | Durand & Hilg. | Papaveraceae | 8 |
| Argentina anserina | (L.) Rydb. | Rosaceae | 8 |
| Argentina pacifica | (Howell) Rydb. | Rosaceae | 8 |
| Aristida oligantha | Michx. | Poaceae | 8 |
| Armeria maritima | (Mill.) Willd. | Plumbaginaceae | 8 |
| Arnica cernua | Howell | Asteraceae | 8 |
| Arnica chamissonis | Less. | Asteraceae | 8 |
| Arnica cordifolia | Hook. | Asteraceae | 8 |
| Arnica discoidea | Benth. | Asteraceae | 8 |
| Arnica fulgens | Pursh | Asteraceae | 8 |
| Arnica gracilis | Rydb. | Asteraceae | 8 |
| Arnica lanceolata | Nutt. | Asteraceae | 8 |
| Arnica latifolia | Bong. | Asteraceae | 8 |
| Arnica longifolia | D.C.Eaton | Asteraceae | 8 |
| Arnica mollis | Hook. | Asteraceae | 8 |
| Arnica parryi | A.Gray | Asteraceae | 8 |
| Arnica rydbergii | Greene | Asteraceae | 8 |
| Arnica sororia | Greene | Asteraceae | 8 |
| Arnica spathulata | Greene | Asteraceae | 8 |
| Arnica viscosa | A.Gray | Asteraceae | 8 |
| Artemisia albicans | Sòn.Garcia, Garnatje, McArthur, Pellicer, S.C.Sand. & Vallès-Xirau | Asteraceae | 8 |
| Artemisia arbuscula | Nutt. | Asteraceae | 8 |
| Artemisia biennis | Willd. | Asteraceae | 8 |
| Artemisia campestris | L. | Asteraceae | 8 |
| Artemisia cana | Pursh | Asteraceae | 8 |
| Artemisia douglasiana | Besser | Asteraceae | 8 |
| Artemisia dracunculus | L. | Asteraceae | 8 |
| Artemisia ludoviciana | Nutt. | Asteraceae | 8 |
| Artemisia michauxiana | Besser | Asteraceae | 8 |
| Artemisia nova | A.Nelson | Asteraceae | 8 |
| Artemisia pycnocephala | DC. | Asteraceae | 8 |
| Artemisia rigida | A.Gray | Asteraceae | 8 |
| Artemisia spiciformis | Osterh. | Asteraceae | 8 |
| Artemisia suksdorfii | Piper | Asteraceae | 8 |
| Artemisia tilesii | Ledeb. | Asteraceae | 8 |
| Artemisia tridentata | Nutt. | Asteraceae | 8 |
| Artemisia tripartita | Rydb. | Asteraceae | 8 |
| Aruncus dioicus | (Walter) Fernald | Rosaceae | 8 |
| Asarum caudatum | Lindl. | Aristolochiaceae | 8 |
| Asarum hartwegii | S.Watson | Aristolochiaceae | 8 |
| Asarum marmoratum | Piper | Aristolochiaceae | 8 |
| Asclepias cordifolia | (Benth.) Jeps. | Apocynaceae | 8 |
| Asclepias cryptoceras | S.Watson | Apocynaceae | 8 |
| Asclepias fascicularis | Decne. | Apocynaceae | 8 |
| Asclepias speciosa | Torr. | Apocynaceae | 8 |
| Askellia pygmaea | (Ledeb.) Sennikov | Asteraceae | 8 |
| Aspidotis densa | (Brack.) Lellinger | Pteridaceae | 8 |
| Asplenium septentrionale | (L.) Hoffm. | Aspleniaceae | 8 |
| Asplenium trichomanes | L. | Aspleniaceae | 8 |
| Asplenium viride | Huds. | Aspleniaceae | 8 |
| Astragalus agrestis | Douglas ex G.Don | Fabaceae | 8 |
| Astragalus alpinus | L. | Fabaceae | 8 |
| Astragalus atratus | S.Watson | Fabaceae | 8 |
| Astragalus beckwithii | Torr. & A.Gray | Fabaceae | 8 |
| Astragalus californicus | (A.Gray) Greene | Fabaceae | 8 |
| Astragalus calycosus | Torr. ex S.Watson | Fabaceae | 8 |
| Astragalus canadensis | L. | Fabaceae | 8 |
| Astragalus collinus | (Hook.) Douglas ex G.Don | Fabaceae | 8 |
| Astragalus conjunctus | S.Watson | Fabaceae | 8 |
| Astragalus curvicarpus | (E.Sheld.) J.F.Macbr. | Fabaceae | 8 |
| Astragalus eremiticus | E.Sheld. | Fabaceae | 8 |
| Astragalus filipes | Torr. ex A.Gray | Fabaceae | 8 |
| Astragalus gambelianus | E.Sheld. | Fabaceae | 8 |
| Astragalus iodanthus | S.Watson | Fabaceae | 8 |
| Astragalus kentrophyta | A.Gray | Fabaceae | 8 |
| Astragalus laxmannii | Jacq. | Fabaceae | 8 |
| Astragalus lemmonii | A.Gray | Fabaceae | 8 |
| Astragalus lentiginosus | Douglas ex Hook. | Fabaceae | 8 |
| Astragalus malacus | A.Gray | Fabaceae | 8 |
| Astragalus multiflorus | (Pursh) A.Gray | Fabaceae | 8 |
| Astragalus newberryi | A.Gray | Fabaceae | 8 |
| Astragalus obscurus | S.Watson | Fabaceae | 8 |
| Astragalus platytropis | A.Gray | Fabaceae | 8 |
| Astragalus purshii | Douglas ex G.Don | Fabaceae | 8 |
| Astragalus robbinsii | (Oakes) A.Gray | Fabaceae | 8 |
| Astragalus salmonis | M.E.Jones | Fabaceae | 8 |
| Astragalus sclerocarpus | A.Gray | Fabaceae | 8 |
| Astragalus solitarius | M.Peck | Fabaceae | 8 |
| Astragalus sterilis | Barneby | Fabaceae | 8 |
| Astragalus succumbens | Douglas ex Hook. | Fabaceae | 8 |
| Astragalus whitneyi | A.Gray | Fabaceae | 8 |
| Athyrium americanum | (Butters) Maxon | Athyriaceae | 8 |
| Athysanus pusillus | Greene | Brassicaceae | 8 |
| Atriplex argentea | Nutt. | Chenopodiaceae | 8 |
| Atriplex canescens | (Pursh) Nutt. | Chenopodiaceae | 8 |
| Atriplex confertifolia | (Torr. & Frém.) S.Watson | Chenopodiaceae | 8 |
| Atriplex patula | L. | Chenopodiaceae | 8 |
| Atriplex phyllostegia | (Torr. ex S.Watson) S.Watson | Chenopodiaceae | 8 |
| Azolla filiculoides | Lam. | Salviniaceae | 8 |
| Baccharis glutinosa | Pers. | Asteraceae | 8 |
| Baccharis pilularis | DC. | Asteraceae | 8 |
| Balsamorhiza careyana | A.Gray | Asteraceae | 8 |
| Balsamorhiza deltoidea | Nutt. | Asteraceae | 8 |
| Balsamorhiza hookeri | Nutt. | Asteraceae | 8 |
| Balsamorhiza incana | Nutt. | Asteraceae | 8 |
| Balsamorhiza macrolepis | W.M.Sharp | Asteraceae | 8 |
| Balsamorhiza macrophylla | Nutt. | Asteraceae | 8 |
| Balsamorhiza sericea | W.A.Weber | Asteraceae | 8 |
| Balsamorhiza serrata | A.Nelson & J.F.Macbr. | Asteraceae | 8 |
| Barbarea orthoceras | Ledeb. | Brassicaceae | 8 |
| Beckmannia syzigachne | (Steud.) Fernald | Poaceae | 8 |
| Berberis aquifolium | Pursh | Berberidaceae | 8 |
| Berberis nervosa | Pursh | Berberidaceae | 8 |
| Berberis pinnata | Lag. | Berberidaceae | 8 |
| Berberis piperiana | (Abrams) McMinn | Berberidaceae | 8 |
| Berberis pumila | Greene | Berberidaceae | 8 |
| Berberis repens | Lindl. | Berberidaceae | 8 |
| Berula erecta | (Huds.) Coville | Apiaceae | 8 |
| Betula glandulosa | Michx. | Betulaceae | 8 |
| Betula occidentalis | Hook. | Betulaceae | 8 |
| Betula papyrifera | Marshall | Betulaceae | 8 |
| Betula pumila | L. | Betulaceae | 8 |
| Bidens beckii | Torr. ex Spreng. | Asteraceae | 8 |
| Bidens cernua | L. | Asteraceae | 8 |
| Bidens frondosa | L. | Asteraceae | 8 |
| Bidens tripartita | L. | Asteraceae | 8 |
| Bidens vulgata | Greene | Asteraceae | 8 |
| Blepharidachne kingii | (S.Watson) Hack. | Poaceae | 8 |
| Blepharipappus scaber | Hook. | Asteraceae | 8 |
| Blitum capitatum | L. | Chenopodiaceae | 8 |
| Blitum nuttallianum | Schult. | Chenopodiaceae | 8 |
| Boechera angustifolia | (Nutt.) Dorn | Brassicaceae | 8 |
| Boechera breweri | (S.Watson) Al-Shehbaz | Brassicaceae | 8 |
| Boechera davidsonii | (Greene) N.H.Holmgren | Brassicaceae | 8 |
| Boechera divaricarpa | (A.Nelson) Á.Löve & D.Löve | Brassicaceae | 8 |
| Boechera howellii | (S.Watson) Windham & Al-Shehbaz | Brassicaceae | 8 |
| Boechera koehleri | (Howell) Al-Shehbaz | Brassicaceae | 8 |
| Boechera lemmonii | (S.Watson) W.A.Weber | Brassicaceae | 8 |
| Boechera lyallii | (S.Watson) Dorn | Brassicaceae | 8 |
| Boechera pauciflora | (Nutt.) Windham & Al-Shehbaz | Brassicaceae | 8 |
| Boechera pendulocarpa | (A.Nelson) Windham & Al-Shehbaz | Brassicaceae | 8 |
| Boechera platysperma | (A.Gray) Al-Shehbaz | Brassicaceae | 8 |
| Boechera polyantha | (Greene) Windham & Al-Shehbaz | Brassicaceae | 8 |
| Boechera puberula | (Nutt.) Dorn | Brassicaceae | 8 |
| Boechera retrofracta | (Graham) Á.Löve & D.Löve | Brassicaceae | 8 |
| Boechera sparsiflora | (Nutt.) Dorn | Brassicaceae | 8 |
| Boechera subpinnatifida | (S.Watson) Al-Shehbaz | Brassicaceae | 8 |
| Bolboschoenus fluviatilis | (Torr.) Soják | Cyperaceae | 8 |
| Bolboschoenus maritimus | (L.) Palla | Cyperaceae | 8 |
| Boltonia asteroides | L'Hér. | Asteraceae | 8 |
| Botrychium ascendens | W.H.Wagner | Ophioglossaceae | 8 |
| Botrychium campestre | W.H.Wagner & Farrar | Ophioglossaceae | 8 |
| Botrychium crenulatum | W.H.Wagner | Ophioglossaceae | 8 |
| Botrychium lanceolatum | (Gmel.) Ångstr. | Ophioglossaceae | 8 |
| Botrychium lineare | W.H.Wagner | Ophioglossaceae | 8 |
| Botrychium minganense | Vict. | Ophioglossaceae | 8 |
| Botrychium montanum | W.H.Wagner | Ophioglossaceae | 8 |
| Botrychium paradoxum | W.H.Wagner | Ophioglossaceae | 8 |
| Botrychium pedunculosum | W.H.Wagner | Ophioglossaceae | 8 |
| Botrychium pinnatum | H.St.John | Ophioglossaceae | 8 |
| Botrychium pumicola | Coville ex Underw. | Ophioglossaceae | 8 |
| Botrychium simplex | E.Hitchc. | Ophioglossaceae | 8 |
| Botrypus virginianus | (L.) Michx. | Ophioglossaceae | 8 |
| Bouteloua barbata | Lag. | Poaceae | 8 |
| Bouteloua curtipendula | (Michx.) Torr. | Poaceae | 8 |
| Boykinia major | A.Gray | Saxifragaceae | 8 |
| Boykinia occidentalis | Torr. & A.Gray | Saxifragaceae | 8 |
| Brasenia schreberi | J.F.Gmel. | Cabombaceae | 8 |
| Brewerimitella breweri | (A.Gray) R.A.Folk & Y.Okuyama | Saxifragaceae | 8 |
| Brewerimitella ovalis | (Greene) R.A.Folk & Y.Okuyama | Saxifragaceae | 8 |
| Brickellia grandiflora | Nutt. | Asteraceae | 8 |
| Brickellia greenei | A.Gray | Asteraceae | 8 |
| Brickellia microphylla | (Nutt.) A.Gray | Asteraceae | 8 |
| Brickellia oblongifolia | Nutt. | Asteraceae | 8 |
| Brodiaea coronaria | (Salisb.) Jeps. | Asparagaceae | 8 |
| Brodiaea elegans | Hoover | Asparagaceae | 8 |
| Brodiaea terrestris | Kellogg | Asparagaceae | 8 |
| Bromus carinatus | Hook. & Arn. | Poaceae | 8 |
| Bromus ciliatus | L. | Poaceae | 8 |
| Bromus laevipes | Shear | Poaceae | 8 |
| Bromus pumpellianus | Scribn. | Poaceae | 8 |
| Bromus sitchensis | Trin. | Poaceae | 8 |
| Bromus vulgaris | (Hook.) Shear | Poaceae | 8 |
| Bupleurum americanum | J.M.Coult. & Rose | Apiaceae | 8 |
| Cacaliopsis nardosmia | (A.Gray) A.Gray | Asteraceae | 8 |
| Calamagrostis breviligulata | (Fernald) Saarela | Poaceae | 8 |
| Calamagrostis canadensis | (Michx.) P.Beauv. | Poaceae | 8 |
| Calamagrostis inexpansa | A.Gray | Poaceae | 8 |
| Calamagrostis nutkaensis | (J.Presl) Steud. | Poaceae | 8 |
| Calamagrostis purpurascens | R.Br. | Poaceae | 8 |
| Calamagrostis purpurea | (Trin.) Trin. | Poaceae | 8 |
| Calamagrostis rubescens | Buckley | Poaceae | 8 |
| Calamagrostis stricta | (Timm) Koeler | Poaceae | 8 |
| Calamagrostis utsutsuensis | Otting & B.L.Wilson | Poaceae | 8 |
| Calandrinia ciliata | (Ruiz & Pav.) DC. | Montiaceae | 8 |
| California macrophylla | (Hook. & Arn.) Aldasoro, C.Navarro, P.Vargas, L.Sáez & Aedo | Geraniaceae | 8 |
| Calliscirpus criniger | (A.Gray) C.N.Gilmour, J.R.Starr & Naczi | Cyperaceae | 8 |
| Callitriche hermaphroditica | L. | Plantaginaceae | 8 |
| Callitriche heterophylla | Pursh | Plantaginaceae | 8 |
| Callitriche palustris | L. | Plantaginaceae | 8 |
| Callitropsis nootkatensis | (D.Don) Oerst. | Cupressaceae | 8 |
| Calocedrus decurrens | (Torr.) Florin | Cupressaceae | 8 |
| Calochortus bruneaunis | A.Nelson & J.F.Macbr. | Liliaceae | 8 |
| Calochortus elegans | Pursh | Liliaceae | 8 |
| Calochortus eurycarpus | S.Watson | Liliaceae | 8 |
| Calochortus howellii | S.Watson | Liliaceae | 8 |
| Calochortus leichtlinii | Hook.f. | Liliaceae | 8 |
| Calochortus macrocarpus | Douglas | Liliaceae | 8 |
| Calochortus nudus | S.Watson | Liliaceae | 8 |
| Calochortus subalpinus | Piper | Liliaceae | 8 |
| Calochortus tolmiei | Hook. & Arn. | Liliaceae | 8 |
| Calochortus uniflorus | Hook. & Arn. | Liliaceae | 8 |
| Caltha biflora | DC. | Ranunculaceae | 8 |
| Caltha chionophila | Greene | Ranunculaceae | 8 |
| Caltha leptosepala | DC. | Ranunculaceae | 8 |
| Caltha palustris | L. | Ranunculaceae | 8 |
| Calycadenia truncata | DC. | Asteraceae | 8 |
| Calypso bulbosa | (L.) Oakes | Orchidaceae | 8 |
| Calystegia atriplicifolia | Hallier f. | Convolvulaceae | 8 |
| Calystegia occidentalis | (A.Gray) Brummitt | Convolvulaceae | 8 |
| Calystegia sepium | (L.) R.Br. | Convolvulaceae | 8 |
| Camassia leichtlinii | (Baker) S.Watson | Asparagaceae | 8 |
| Camassia quamash | (Pursh) Greene | Asparagaceae | 8 |
| Camissonia contorta | (Douglas) Kearney | Onagraceae | 8 |
| Camissonia parvula | (Nutt. ex Torr. & A.Gray) P.H.Raven | Onagraceae | 8 |
| Camissonia pusilla | P.H.Raven | Onagraceae | 8 |
| Camissoniopsis cheiranthifolia | (Hornem. ex Spreng.) W.L.Wagner & Hoch | Onagraceae | 8 |
| Campanula petiolata | A.DC. | Campanulaceae | 8 |
| Campanula scabrella | Engelm. | Campanulaceae | 8 |
| Campanula scouleri | Hook. ex A.DC. | Campanulaceae | 8 |
| Canadanthus modestus | (Lindl.) G.L.Nesom | Asteraceae | 8 |
| Cardamine angulata | Hook. | Brassicaceae | 8 |
| Cardamine bellidifolia | L. | Brassicaceae | 8 |
| Cardamine breweri | S.Watson | Brassicaceae | 8 |
| Cardamine californica | (Nutt.) Greene | Brassicaceae | 8 |
| Cardamine cordifolia | A.Gray | Brassicaceae | 8 |
| Cardamine nuttallii | Greene | Brassicaceae | 8 |
| Cardamine oligosperma | Nutt. | Brassicaceae | 8 |
| Cardamine parviflora | L. | Brassicaceae | 8 |
| Cardamine penduliflora | O.E.Schulz | Brassicaceae | 8 |
| Cardamine pensylvanica | Muhl. ex Willd. | Brassicaceae | 8 |
| Carex alascana | Boeckeler | Cyperaceae | 8 |
| Carex amplifolia | Boott | Cyperaceae | 8 |
| Carex aquatilis | Wahlenb. | Cyperaceae | 8 |
| Carex atherodes | Spreng. | Cyperaceae | 8 |
| Carex athrostachya | Olney | Cyperaceae | 8 |
| Carex atrosquama | Mack. | Cyperaceae | 8 |
| Carex aurea | Nutt. | Cyperaceae | 8 |
| Carex barbarae | Dewey | Cyperaceae | 8 |
| Carex bebbii | (L.H.Bailey) Olney ex Fernald | Cyperaceae | 8 |
| Carex breweri | Boott | Cyperaceae | 8 |
| Carex brunnescens | (Pers.) Poir. | Cyperaceae | 8 |
| Carex buxbaumii | Wahlenb. | Cyperaceae | 8 |
| Carex canescens | L. | Cyperaceae | 8 |
| Carex capillaris | L. | Cyperaceae | 8 |
| Carex capitata | Sol. | Cyperaceae | 8 |
| Carex concinna | R.Br. | Cyperaceae | 8 |
| Carex concinnoides | Mack. | Cyperaceae | 8 |
| Carex crawfordii | Fernald | Cyperaceae | 8 |
| Carex cusickii | Mack. | Cyperaceae | 8 |
| Carex deflexa | Hornem. | Cyperaceae | 8 |
| Carex densa | (L.H.Bailey) L.H.Bailey | Cyperaceae | 8 |
| Carex diandra | Schrank | Cyperaceae | 8 |
| Carex disperma | Dewey | Cyperaceae | 8 |
| Carex douglasii | Boott | Cyperaceae | 8 |
| Carex duriuscula | C.A.Mey. | Cyperaceae | 8 |
| Carex echinata | Murray | Cyperaceae | 8 |
| Carex exsiccata | L.H.Bailey | Cyperaceae | 8 |
| Carex feta | L.H.Bailey | Cyperaceae | 8 |
| Carex filifolia | Nutt. | Cyperaceae | 8 |
| Carex fracta | Mack. | Cyperaceae | 8 |
| Carex garberi | Fernald | Cyperaceae | 8 |
| Carex gynodynama | Olney | Cyperaceae | 8 |
| Carex haydeniana | Olney | Cyperaceae | 8 |
| Carex hendersonii | L.H.Bailey | Cyperaceae | 8 |
| Carex heteroneura | W.Boott | Cyperaceae | 8 |
| Carex hoodii | Boott | Cyperaceae | 8 |
| Carex idahoa | L.H.Bailey | Cyperaceae | 8 |
| Carex illota | L.H.Bailey | Cyperaceae | 8 |
| Carex inops | L.H.Bailey | Cyperaceae | 8 |
| Carex interior | L.H.Bailey | Cyperaceae | 8 |
| Carex interrupta | Boeckeler | Cyperaceae | 8 |
| Carex kelloggii | W.Boott | Cyperaceae | 8 |
| Carex laeviculmis | Meinsh. | Cyperaceae | 8 |
| Carex leporina | L. | Cyperaceae | 8 |
| Carex leptalea | Wahlenb. | Cyperaceae | 8 |
| Carex leptopoda | Mack. | Cyperaceae | 8 |
| Carex limosa | L. | Cyperaceae | 8 |
| Carex livida | (Wahlenb.) Willd. | Cyperaceae | 8 |
| Carex luzulina | Olney | Cyperaceae | 8 |
| Carex lyngbyei | Hornem. | Cyperaceae | 8 |
| Carex macrocephala | Willd. ex Spreng. | Cyperaceae | 8 |
| Carex macrochaeta | C.A.Mey. | Cyperaceae | 8 |
| Carex media | R.Br. | Cyperaceae | 8 |
| Carex mendocinensis | Olney ex Boott | Cyperaceae | 8 |
| Carex mertensii | J.D.Prescott ex Bong. | Cyperaceae | 8 |
| Carex micropoda | C.A.Mey. | Cyperaceae | 8 |
| Carex microptera | Mack. | Cyperaceae | 8 |
| Carex multicaulis | L.H.Bailey | Cyperaceae | 8 |
| Carex myosuroides | Vill. | Cyperaceae | 8 |
| Carex neurophora | Mack. | Cyperaceae | 8 |
| Carex nigricans | C.A.Mey. | Cyperaceae | 8 |
| Carex nudata | W.Boott | Cyperaceae | 8 |
| Carex obnupta | L.H.Bailey | Cyperaceae | 8 |
| Carex pachystachya | Cham. ex Steud. | Cyperaceae | 8 |
| Carex pellita | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex petasata | Dewey | Cyperaceae | 8 |
| Carex phaeocephala | Piper | Cyperaceae | 8 |
| Carex praegracilis | W.Boott | Cyperaceae | 8 |
| Carex praticola | Rydb. | Cyperaceae | 8 |
| Carex preslii | Steud. | Cyperaceae | 8 |
| Carex raynoldsii | Dewey | Cyperaceae | 8 |
| Carex retrorsa | Schwein. | Cyperaceae | 8 |
| Carex rossii | Boott | Cyperaceae | 8 |
| Carex scabriuscula | Mack. | Cyperaceae | 8 |
| Carex scirpoidea | Michx. | Cyperaceae | 8 |
| Carex scoparia | Schkuhr ex Willd. | Cyperaceae | 8 |
| Carex serratodens | S.Watson | Cyperaceae | 8 |
| Carex simpliciuscula | Wahlenb. | Cyperaceae | 8 |
| Carex spectabilis | Dewey | Cyperaceae | 8 |
| Carex stipata | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex straminiformis | L.H.Bailey | Cyperaceae | 8 |
| Carex subfusca | W.Boott | Cyperaceae | 8 |
| Carex subnigricans | Stacey | Cyperaceae | 8 |
| Carex tahoensis | Smiley | Cyperaceae | 8 |
| Carex tenera | Dewey | Cyperaceae | 8 |
| Carex trichocarpa | Muhl. ex Willd. | Cyperaceae | 8 |
| Carex tumulicola | Mack. | Cyperaceae | 8 |
| Carex unilateralis | Mack. | Cyperaceae | 8 |
| Carex utriculata | Boott | Cyperaceae | 8 |
| Carex vallicola | Dewey | Cyperaceae | 8 |
| Carex vesicaria | L. | Cyperaceae | 8 |
| Carex vulpinoidea | Michx. | Cyperaceae | 8 |
| Carex whitneyi | Olney | Cyperaceae | 8 |
| Cascadia nuttallii | A.M.Johnson | Saxifragaceae | 8 |
| Cassiope mertensiana | (Bong.) G.Don | Ericaceae | 8 |
| Castilleja ambigua | Hook. & Arn. | Orobanchaceae | 8 |
| Castilleja angustifolia | (Nutt.) G.Don | Orobanchaceae | 8 |
| Castilleja applegatei | Fernald | Orobanchaceae | 8 |
| Castilleja arachnoidea | Greenm. | Orobanchaceae | 8 |
| Castilleja attenuata | (A.Gray) T.I.Chuang & Heckard | Orobanchaceae | 8 |
| Castilleja brevilobata | Piper | Orobanchaceae | 8 |
| Castilleja campestris | (Benth.) T.I.Chuang & Heckard | Orobanchaceae | 8 |
| Castilleja chromosa | A.Nelson | Orobanchaceae | 8 |
| Castilleja cusickii | Greenm. | Orobanchaceae | 8 |
| Castilleja elata | Piper | Orobanchaceae | 8 |
| Castilleja flava | S.Watson | Orobanchaceae | 8 |
| Castilleja hispida | Benth. | Orobanchaceae | 8 |
| Castilleja lacera | (Benth.) T.I.Chuang & Heckard | Orobanchaceae | 8 |
| Castilleja levisecta | Greenm. | Orobanchaceae | 8 |
| Castilleja linariifolia | Benth. | Orobanchaceae | 8 |
| Castilleja litoralis | Pennell | Orobanchaceae | 8 |
| Castilleja lutescens | (Greenm.) Rydb. | Orobanchaceae | 8 |
| Castilleja mendocinensis | (Eastw.) Pennell | Orobanchaceae | 8 |
| Castilleja miniata | Douglas ex Benth. | Orobanchaceae | 8 |
| Castilleja minor | (A.Gray) A.Gray | Orobanchaceae | 8 |
| Castilleja pallescens | (A.Gray) Greenm. | Orobanchaceae | 8 |
| Castilleja parviflora | Bong. | Orobanchaceae | 8 |
| Castilleja pilosa | (S.Watson) Rydb. | Orobanchaceae | 8 |
| Castilleja pruinosa | Fernald | Orobanchaceae | 8 |
| Castilleja rhexiifolia | Rydb. | Orobanchaceae | 8 |
| Castilleja rubicundula | (Jeps.) T.I.Chuang & Heckard | Orobanchaceae | 8 |
| Castilleja rupicola | Piper ex Fernald | Orobanchaceae | 8 |
| Castilleja schizotricha | Greenm. | Orobanchaceae | 8 |
| Castilleja suksdorfii | A.Gray | Orobanchaceae | 8 |
| Castilleja tenuis | (A.Heller) T.I.Chuang & Heckard | Orobanchaceae | 8 |
| Castilleja thompsonii | Pennell | Orobanchaceae | 8 |
| Castilleja viscidula | A.Gray | Orobanchaceae | 8 |
| Castilleja xanthotricha | Pennell | Orobanchaceae | 8 |
| Catabrosa aquatica | (L.) P.Beauv. | Poaceae | 8 |
| Ceanothus cordulatus | Kellogg | Rhamnaceae | 8 |
| Ceanothus cuneatus | (Hook.) Nutt. | Rhamnaceae | 8 |
| Ceanothus parryi | Trel. | Rhamnaceae | 8 |
| Ceanothus prostratus | Benth. | Rhamnaceae | 8 |
| Ceanothus pumilus | Greene | Rhamnaceae | 8 |
| Ceanothus sanguineus | Pursh | Rhamnaceae | 8 |
| Ceanothus thyrsiflorus | Eschsch. | Rhamnaceae | 8 |
| Ceanothus velutinus | Douglas | Rhamnaceae | 8 |
| Celtis reticulata | Torr. | Cannabaceae | 8 |
| Centromadia fitchii | Greene | Asteraceae | 8 |
| Centromadia pungens | Greene | Asteraceae | 8 |
| Cephalanthera austiniae | (A.Gray) A.Heller | Orchidaceae | 8 |
| Cerastium beeringianum | Cham. & Schltdl. | Caryophyllaceae | 8 |
| Cerastium brachypodum | (Engelm. ex A.Gray) B.L.Rob. | Caryophyllaceae | 8 |
| Cerastium nutans | Raf. | Caryophyllaceae | 8 |
| Ceratophyllum demersum | L. | Ceratophyllaceae | 8 |
| Ceratophyllum echinatum | A.Gray | Ceratophyllaceae | 8 |
| Cercis occidentalis | Torr. ex A.Gray | Fabaceae | 8 |
| Cercocarpus betuloides | Nutt. | Rosaceae | 8 |
| Cercocarpus ledifolius | Nutt. | Rosaceae | 8 |
| Chaenactis cusickii | A.Gray | Asteraceae | 8 |
| Chaenactis douglasii | Hook. & Arn. | Asteraceae | 8 |
| Chaenactis macrantha | D.C.Eaton | Asteraceae | 8 |
| Chaenactis nevii | A.Gray | Asteraceae | 8 |
| Chaenactis stevioides | Hook. & Arn. | Asteraceae | 8 |
| Chaenactis suffrutescens | A.Gray | Asteraceae | 8 |
| Chaenactis xantiana | A.Gray | Asteraceae | 8 |
| Chaetadelpha wheeleri | A.Gray ex S.Watson | Asteraceae | 8 |
| Chamaebatiaria millefolium | (Torr.) Maxim. | Rosaceae | 8 |
| Chamaecyparis lawsoniana | (A.Murray bis) Parl. | Cupressaceae | 8 |
| Chenopodium atrovirens | Rydb. | Chenopodiaceae | 8 |
| Chenopodium berlandieri | Moq. | Chenopodiaceae | 8 |
| Chenopodium fremontii | S.Watson | Chenopodiaceae | 8 |
| Chenopodium leptophyllum | (Nutt. ex Moq.) B.D.Jacks. | Chenopodiaceae | 8 |
| Chenopodium rubrum | L. | Chenopodiaceae | 8 |
| Cherleria biflora | (L.) A. J. Moore & Dillenb. | Caryophyllaceae | 8 |
| Cherleria obtusiloba | (Rydb.) A.J.Moore & Dillenb. | Caryophyllaceae | 8 |
| Chimaphila menziesii | (R.Br. ex D.Don) Spreng. | Ericaceae | 8 |
| Chimaphila umbellata | (L.) W.P.C.Barton | Ericaceae | 8 |
| Chlorocrambe hastata | (S.Watson) Rydb. | Brassicaceae | 8 |
| Chlorogalum pomeridianum | (DC.) Kunth | Asparagaceae | 8 |
| Chloropyron maritimum | (Nutt. ex Benth.) A.Heller | Orobanchaceae | 8 |
| Chorizanthe brevicornu | Torr. | Polygonaceae | 8 |
| Chorizanthe membranacea | Benth. | Polygonaceae | 8 |
| Chorizanthe watsonii | Torr. & A.Gray | Polygonaceae | 8 |
| Chrysolepis chrysophylla | (Douglas ex Hook.) Hjelmq. | Fagaceae | 8 |
| Chrysolepis sempervirens | (Kellogg) Hjelmq. | Fagaceae | 8 |
| Chrysopsis oregona | (Nutt.) A.Gray | Asteraceae | 8 |
| Chrysosplenium glechomifolium | Nutt. | Saxifragaceae | 8 |
| Chrysothamnus viscidiflorus | Nutt. | Asteraceae | 8 |
| Chylismia claviformis | (Torr. & Frém.) A.Heller | Onagraceae | 8 |
| Chylismia scapoidea | (Torr. & A.Gray) Small | Onagraceae | 8 |
| Chylismiella pterosperma | (S.Watson) W.L.Wagner & Hoch | Onagraceae | 8 |
| Cicendia quadrangularis | (Lam.) Griseb. | Gentianaceae | 8 |
| Cicuta bulbifera | L. | Apiaceae | 8 |
| Cicuta douglasii | J.M.Coult. & Rose | Apiaceae | 8 |
| Cicuta maculata | L. | Apiaceae | 8 |
| Cinna latifolia | (Trevir. ex Göpp.) Griseb. | Poaceae | 8 |
| Circaea alpina | L. | Onagraceae | 8 |
| Cirsium andersonii | Petr. | Asteraceae | 8 |
| Cirsium brevistylum | Cronquist | Asteraceae | 8 |
| Cirsium cymosum | (Greene) J.T.Howell | Asteraceae | 8 |
| Cirsium douglasii | DC. | Asteraceae | 8 |
| Cirsium eatonii | (A.Gray) B.L.Rob. | Asteraceae | 8 |
| Cirsium edule | Nutt. | Asteraceae | 8 |
| Cirsium occidentale | (Nutt.) Jeps. | Asteraceae | 8 |
| Cirsium remotifolium | DC. | Asteraceae | 8 |
| Cirsium scariosum | Nutt. | Asteraceae | 8 |
| Cirsium undulatum | (Nutt.) Spreng. | Asteraceae | 8 |
| Cistanthe monosperma | (Greene) Hershk. | Montiaceae | 8 |
| Cistanthe rosea | (S.Watson) Hershk. | Montiaceae | 8 |
| Cistanthe umbellata | (Torr.) Hershk. | Montiaceae | 8 |
| Clarkia amoena | (Lehm.) A.Nelson & J.F.Macbr. | Onagraceae | 8 |
| Clarkia gracilis | A.Nelson & J.F.Macbr. | Onagraceae | 8 |
| Clarkia heterandra | (Torr.) F.H.Lewis & P.H.Raven | Onagraceae | 8 |
| Clarkia lassenensis | (Eastw.) F.H.Lewis & M.E.Lewis | Onagraceae | 8 |
| Clarkia pulchella | Pursh | Onagraceae | 8 |
| Clarkia purpurea | (Curtis) A.Nelson & J.F.Macbr. | Onagraceae | 8 |
| Clarkia rhomboidea | Douglas | Onagraceae | 8 |
| Claytonia cordifolia | S.Watson | Montiaceae | 8 |
| Claytonia exigua | Torr. & A.Gray | Montiaceae | 8 |
| Claytonia lanceolata | Pursh | Montiaceae | 8 |
| Claytonia megarhiza | (A.Gray) Parry ex S.Watson | Montiaceae | 8 |
| Claytonia nevadensis | S.Watson | Montiaceae | 8 |
| Claytonia parviflora | Douglas | Montiaceae | 8 |
| Claytonia perfoliata | Donn ex Willd. | Montiaceae | 8 |
| Claytonia rubra | (Howell) Tidestr. | Montiaceae | 8 |
| Claytonia sibirica | L. | Montiaceae | 8 |
| Claytonia umbellata | S.Watson | Montiaceae | 8 |
| Clematis hirsutissima | Pursh | Ranunculaceae | 8 |
| Clematis ligusticifolia | Nutt. | Ranunculaceae | 8 |
| Clematis occidentalis | (Hornem.) DC. | Ranunculaceae | 8 |
| Cleome dodecandra | L. | Cleomaceae | 8 |
| Cleomella hillmanii | A.Nelson | Cleomaceae | 8 |
| Cleomella lutea | (Hook.) Roalson & J.C.Hall | Cleomaceae | 8 |
| Cleomella parviflora | A.Gray | Cleomaceae | 8 |
| Cleomella platycarpa | (Torr.) Roalson & J.C.Hall | Cleomaceae | 8 |
| Cleomella plocasperma | S.Watson | Cleomaceae | 8 |
| Cleomella serrulata | (Pursh) Roalson & J.C.Hall | Cleomaceae | 8 |
| Clintonia andrewsiana | Torr. | Liliaceae | 8 |
| Clintonia uniflora | (Menzies ex Schult. & Schult.f.) Kunth | Liliaceae | 8 |
| Cochlearia groenlandica | L. | Brassicaceae | 8 |
| Coleanthus subtilis | (Tratt.) Seidel ex Roem. & Schult. | Poaceae | 8 |
| Coleataenia rigidula | (Bosc ex Nees) LeBlond | Poaceae | 8 |
| Collinsia grandiflora | Douglas ex Lindl. | Plantaginaceae | 8 |
| Collinsia linearis | A.Gray | Plantaginaceae | 8 |
| Collinsia parviflora | Douglas ex Lindl. | Plantaginaceae | 8 |
| Collinsia rattanii | A.Gray | Plantaginaceae | 8 |
| Collinsia sparsiflora | Fisch. & C.A.Mey. | Plantaginaceae | 8 |
| Collomia debilis | Greene | Polemoniaceae | 8 |
| Collomia grandiflora | Douglas ex Lindl. | Polemoniaceae | 8 |
| Collomia heterophylla | Hook. | Polemoniaceae | 8 |
| Collomia larsenii | Payson | Polemoniaceae | 8 |
| Collomia linearis | Nutt. | Polemoniaceae | 8 |
| Collomia tinctoria | Kellogg | Polemoniaceae | 8 |
| Columbiadoria hallii | (A.Gray) G.L.Nesom | Asteraceae | 8 |
| Comandra umbellata | (L.) Nutt. | Santalaceae | 8 |
| Comarum palustre | L. | Rosaceae | 8 |
| Comastoma tenellum | (Rottb.) Toyok. | Gentianaceae | 8 |
| Conioselinum chinense | (L.) Britton, Sterns & Poggenb. | Apiaceae | 8 |
| Conioselinum scopulorum | (A.Gray) J.M.Coult. & Rose | Apiaceae | 8 |
| Conioselinum tataricum | Hoffm. | Apiaceae | 8 |
| Coptis laciniata | A.Gray | Ranunculaceae | 8 |
| Corallorhiza maculata | Raf. | Orchidaceae | 8 |
| Corallorhiza mertensiana | Bong. | Orchidaceae | 8 |
| Corallorhiza striata | Lindl. | Orchidaceae | 8 |
| Corallorhiza trifida | Châtel. | Orchidaceae | 8 |
| Cordylanthus capitatus | Nutt. ex Benth. | Orobanchaceae | 8 |
| Cordylanthus ramosus | Nutt. ex Benth. | Orobanchaceae | 8 |
| Cordylanthus tenuis | A.Gray | Orobanchaceae | 8 |
| Coreopsis tinctoria | Nutt. | Asteraceae | 8 |
| Corethrogyne filaginifolia | (Hook. & Arn.) Nutt. | Asteraceae | 8 |
| Corispermum villosum | Rydb. | Chenopodiaceae | 8 |
| Cornus glabrata | Benth. | Cornaceae | 8 |
| Cornus nuttallii | Audubon ex Torr. & A.Gray | Cornaceae | 8 |
| Cornus sericea | L. | Cornaceae | 8 |
| Cornus sessilis | Torr. | Cornaceae | 8 |
| Corydalis caseana | A.Gray | Papaveraceae | 8 |
| Corydalis scouleri | Hook. | Papaveraceae | 8 |
| Corylus cornuta | Marshall | Betulaceae | 8 |
| Crassula aquatica | (L.) Schönland | Crassulaceae | 8 |
| Crassula connata | A.Berger | Crassulaceae | 8 |
| Crataegus chrysocarpa | Ashe | Rosaceae | 8 |
| Crataegus douglasii | Lindl. | Rosaceae | 8 |
| Crataegus macracantha | (Lindl.) Lodd. ex Loudon | Rosaceae | 8 |
| Crepis acuminata | Nutt. | Asteraceae | 8 |
| Crepis atribarba | A.Heller | Asteraceae | 8 |
| Crepis intermedia | A.Gray | Asteraceae | 8 |
| Crepis occidentalis | Nutt. | Asteraceae | 8 |
| Cressa truxillensis | Kunth | Convolvulaceae | 8 |
| Crocidium multicaule | Hook. | Asteraceae | 8 |
| Cryptantha ambigua | (A.Gray) Greene | Boraginaceae | 8 |
| Cryptantha fendleri | (A.Gray) Greene | Boraginaceae | 8 |
| Cryptantha flaccida | (Douglas ex Lehm.) Greene | Boraginaceae | 8 |
| Cryptantha gracilis | Osterh. | Boraginaceae | 8 |
| Cryptantha intermedia | (A.Gray) Greene | Boraginaceae | 8 |
| Cryptantha leiocarpa | (Fisch. & C.A.Mey.) Greene | Boraginaceae | 8 |
| Cryptantha pterocarya | (Torr.) Greene | Boraginaceae | 8 |
| Cryptantha recurvata | Coville | Boraginaceae | 8 |
| Cryptantha scoparia | A.Nelson | Boraginaceae | 8 |
| Cryptogramma acrostichoides | R.Br. | Pteridaceae | 8 |
| Cryptogramma cascadensis | E.R.Alverson | Pteridaceae | 8 |
| Cryptogramma stelleri | (S.G.Gmel.) Prantl | Pteridaceae | 8 |
| Cuscuta californica | Hook. & Arn. | Convolvulaceae | 8 |
| Cuscuta campestris | Yunck. | Convolvulaceae | 8 |
| Cuscuta cephalanthi | Engelm. | Convolvulaceae | 8 |
| Cuscuta gronovii | Willd. | Convolvulaceae | 8 |
| Cuscuta indecora | Choisy | Convolvulaceae | 8 |
| Cuscuta pacifica | Costea & M.A.R.Wright | Convolvulaceae | 8 |
| Cusickiella douglasii | (A.Gray) Rollins | Brassicaceae | 8 |
| Cycladenia humilis | Benth. | Apocynaceae | 8 |
| Cymopterus glomeratus | (Nutt.) DC. | Apiaceae | 8 |
| Cymopterus longipes | S.Watson | Apiaceae | 8 |
| Cymopterus nivalis | S.Watson | Apiaceae | 8 |
| Cymopterus petraeus | M.E.Jones | Apiaceae | 8 |
| Cymopterus terebinthinus | (Hook.) Torr. & A.Gray | Apiaceae | 8 |
| Cyperus acuminatus | Torr. & Hook. | Cyperaceae | 8 |
| Cyperus bipartitus | Torr. | Cyperaceae | 8 |
| Cyperus eragrostis | Lam. | 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 californicum | A.Gray | Orchidaceae | 8 |
| Cypripedium fasciculatum | Kellogg | Orchidaceae | 8 |
| Cypripedium montanum | Douglas ex Lindl. | Orchidaceae | 8 |
| Cypripedium parviflorum | Salisb. | Orchidaceae | 8 |
| Cystopteris fragilis | (L.) Bernh. | Cystopteridaceae | 8 |
| Dalea ornata | (Douglas ex Hook.) Eaton & Wright | Fabaceae | 8 |
| Damasonium californicum | Torr. | Alismataceae | 8 |
| Danthonia californica | Bol. | Poaceae | 8 |
| Danthonia intermedia | Vasey | Poaceae | 8 |
| Danthonia spicata | (L.) Roem. & Schult. | Poaceae | 8 |
| Danthonia unispicata | (Thurb.) Munro ex Macoun | Poaceae | 8 |
| Darlingtonia californica | Torr. | Sarraceniaceae | 8 |
| Darmera peltata | (Torr. ex Benth.) Voss | Saxifragaceae | 8 |
| Dasiphora fruticosa | (L.) Rydb. | Rosaceae | 8 |
| Daucus pusillus | Michx. | Apiaceae | 8 |
| Delphinium andersonii | A.Gray | Ranunculaceae | 8 |
| Delphinium decorum | Fisch. & C.A.Mey. | Ranunculaceae | 8 |
| Delphinium glareosum | Greene | Ranunculaceae | 8 |
| Delphinium glaucum | S.Watson | Ranunculaceae | 8 |
| Delphinium menziesii | DC. | Ranunculaceae | 8 |
| Delphinium nudicaule | Torr. & A.Gray | Ranunculaceae | 8 |
| Delphinium nuttallianum | Pritz. | Ranunculaceae | 8 |
| Delphinium occidentale | S.Watson ex J.M.Coult. | Ranunculaceae | 8 |
| Delphinium pavonaceum | Ewan | Ranunculaceae | 8 |
| Delphinium trolliifolium | A.Gray | Ranunculaceae | 8 |
| Deschampsia danthonioides | (Trin.) Benth. | Poaceae | 8 |
| Deschampsia elongata | (Hook.) Munro | Poaceae | 8 |
| Descurainia californica | (A.Gray) O.E.Schulz | Brassicaceae | 8 |
| Descurainia incana | (Bernh. ex Fisch. & C.A.Mey.) Dorn | Brassicaceae | 8 |
| Descurainia incisa | (Engelm.) Britton | Brassicaceae | 8 |
| Descurainia longepedicellata | (E.Fourn.) O.E.Schulz | Brassicaceae | 8 |
| Descurainia pinnata | (Walter) Britton | Brassicaceae | 8 |
| Dicentra cucullaria | (L.) Bernh. | Papaveraceae | 8 |
| Dicentra formosa | (Haw.) Walp. | Papaveraceae | 8 |
| Dicentra pauciflora | S.Watson | Papaveraceae | 8 |
| Dicentra uniflora | Kellogg | Papaveraceae | 8 |
| Dichanthelium implicatum | (Scribn.) Kerguélen | Poaceae | 8 |
| Dichanthelium lanuginosum | (Elliott) Gould | Poaceae | 8 |
| Dichelostemma capitatum | (Benth.) Alph.Wood | Asparagaceae | 8 |
| Dichelostemma congestum | (Sm.) Kunth | Asparagaceae | 8 |
| Dichelostemma ida-maia | (Alph.Wood) Greene | Asparagaceae | 8 |
| Dichelostemma multiflorum | (Benth.) A.Heller | Asparagaceae | 8 |
| Dichondra donelliana | Tharp & M.C.Johnst. | Convolvulaceae | 8 |
| Dieteria canescens | (Pursh) Nutt. | Asteraceae | 8 |
| Diphasiastrum complanatum | (L.) Holub | Lycopodiaceae | 8 |
| Diphasiastrum sitchense | (Rupr.) Holub | Lycopodiaceae | 8 |
| Diplachne fusca | (L.) P.Beauv. | Poaceae | 8 |
| Diplacus aurantiacus | (Curtis) Jeps. | Phrymaceae | 8 |
| Diplacus bolanderi | (A.Gray) G.L.Nesom | Phrymaceae | 8 |
| Diplacus cusickioides | G.L.Nesom | Phrymaceae | 8 |
| Diplacus douglasii | (Benth.) G.L.Nesom | Phrymaceae | 8 |
| Diplacus jepsonii | (A.L.Grant) G.L.Nesom | Phrymaceae | 8 |
| Diplacus kelloggii | (Curran ex Greene) G.L.Nesom | Phrymaceae | 8 |
| Diplacus nanus | (Hook. & Arn.) G.L.Nesom | Phrymaceae | 8 |
| Diplacus tricolor | (Hartw. ex Lindl.) G.L.Nesom | Phrymaceae | 8 |
| Distichlis spicata | (L.) Greene | Poaceae | 8 |
| Downingia bacigalupii | Weiler | Campanulaceae | 8 |
| Downingia bicornuta | A.Gray | Campanulaceae | 8 |
| Downingia elegans | (Douglas ex Lindl.) Torr. | Campanulaceae | 8 |
| Downingia insignis | Greene | Campanulaceae | 8 |
| Downingia yina | Applegate | Campanulaceae | 8 |
| Draba albertina | Greene | Brassicaceae | 8 |
| Draba aureola | S.Watson | Brassicaceae | 8 |
| Draba cana | Rydb. | Brassicaceae | 8 |
| Draba densifolia | Nutt. | Brassicaceae | 8 |
| Draba howellii | S.Watson | Brassicaceae | 8 |
| Draba lonchocarpa | Rydb. | Brassicaceae | 8 |
| Draba nemorosa | L. | Brassicaceae | 8 |
| Draba novolympica | Payson & H.St.John | Brassicaceae | 8 |
| Draba oligosperma | Hook. | Brassicaceae | 8 |
| Draba praealta | Greene | Brassicaceae | 8 |
| Dracocephalum parviflorum | Nutt. | Lamiaceae | 8 |
| Drosera anglica | Huds. | Droseraceae | 8 |
| Drosera rotundifolia | L. | Droseraceae | 8 |
| Dryas drummondii | Richardson ex Hook. | Rosaceae | 8 |
| Dryas hookeriana | Juz. | Rosaceae | 8 |
| Drymocallis glandulosa | (Lindl.) Rydb. | Rosaceae | 8 |
| Dryopteris carthusiana | (Vill.) H.P.Fuchs | Dryopteridaceae | 8 |
| Dryopteris expansa | (C.Presl) Fraser-Jenk. & Jermy | Dryopteridaceae | 8 |
| Dryopteris filix-mas | (L.) Schott | Dryopteridaceae | 8 |
| Dudleya farinosa | Britton & Rose | Crassulaceae | 8 |
| Dulichium arundinaceum | (L.) Britton | Cyperaceae | 8 |
| Eatonella nivea | A.Gray | Asteraceae | 8 |
| Echinochloa muricata | (P.Beauv.) Fernald | Poaceae | 8 |
| Echinocystis lobata | (Michx.) Torr. & A.Gray | Cucurbitaceae | 8 |
| Elatine brachysperma | A.Gray | Elatinaceae | 8 |
| Eleocharis acicularis | (L.) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis engelmannii | Steud. | Cyperaceae | 8 |
| Eleocharis erythropoda | Steud. | Cyperaceae | 8 |
| Eleocharis macrostachya | Britton | Cyperaceae | 8 |
| Eleocharis obtusa | (Willd.) Schult. | Cyperaceae | 8 |
| Eleocharis ovata | (Roth) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis palustris | (L.) Roem. & Schult. | Cyperaceae | 8 |
| Eleocharis parvula | (Roem. & Schult.) Link ex Bluff, Nees & Schauer | Cyperaceae | 8 |
| Eleocharis quinqueflora | (Hartmann) O.Schwarz | Cyperaceae | 8 |
| Elliottia pyroliflora | (Bong.) Brim & P.F.Stevens | Ericaceae | 8 |
| Elmera racemosa | (S.Watson) Rydb. | Saxifragaceae | 8 |
| Elodea canadensis | Michx. | Hydrocharitaceae | 8 |
| Elodea nuttallii | (Planch.) H.St.John | Hydrocharitaceae | 8 |
| Elymus canadensis | L. | Poaceae | 8 |
| Elymus elymoides | (Raf.) Swezey | Poaceae | 8 |
| Elymus glaucus | Buckley | Poaceae | 8 |
| Elymus lanceolatus | (Scribn. & J.G.Sm.) Gould | Poaceae | 8 |
| Elymus longifolius | (J.G.Sm.) Gould | Poaceae | 8 |
| Elymus multisetus | (J.G.Sm.) Burtt Davy | Poaceae | 8 |
| Elymus scribneri | (Vasey) M.E.Jones | Poaceae | 8 |
| Elymus smithii | (Rydb.) Gould | Poaceae | 8 |
| Elymus violaceus | (Hornem.) J.Feilberg | Poaceae | 8 |
| Empetrum nigrum | L. | Ericaceae | 8 |
| Enemion hallii | (A.Gray) J.R.Drumm. & Hutch. | Ranunculaceae | 8 |
| Ephedra nevadensis | S.Watson | Ephedraceae | 8 |
| Ephedra viridis | Coville | Ephedraceae | 8 |
| Epilobium anagallidifolium | Lam. | Onagraceae | 8 |
| Epilobium angustifolium | L. | Onagraceae | 8 |
| Epilobium brachycarpum | C.Presl | Onagraceae | 8 |
| Epilobium canum | (Greene) P.H.Raven | Onagraceae | 8 |
| Epilobium ciliatum | Raf. | Onagraceae | 8 |
| Epilobium clavatum | Trel. | Onagraceae | 8 |
| Epilobium densiflorum | (Lindl.) Hoch & P.H.Raven | Onagraceae | 8 |
| Epilobium hornemannii | Rchb. | Onagraceae | 8 |
| Epilobium lactiflorum | Hausskn. | Onagraceae | 8 |
| Epilobium latifolium | L. | Onagraceae | 8 |
| Epilobium leptophyllum | Raf. | Onagraceae | 8 |
| Epilobium luteum | Pursh | Onagraceae | 8 |
| Epilobium minutum | Lindl. | Onagraceae | 8 |
| Epilobium obcordatum | A.Gray | Onagraceae | 8 |
| Epilobium oreganum | Greene | Onagraceae | 8 |
| Epilobium palustre | L. | Onagraceae | 8 |
| Epilobium siskiyouense | (Munz) Hoch & P.H.Raven | Onagraceae | 8 |
| Epipactis gigantea | Douglas | Orchidaceae | 8 |
| Equisetum arvense | L. | Equisetaceae | 8 |
| Equisetum fluviatile | L. | Equisetaceae | 8 |
| Equisetum hyemale | L. | Equisetaceae | 8 |
| Equisetum laevigatum | A.Braun | Equisetaceae | 8 |
| Equisetum palustre | L. | Equisetaceae | 8 |
| Equisetum variegatum | Schleich. ex F.Weber & D.Mohr | Equisetaceae | 8 |
| Eragrostis hypnoides | (Lam.) Britton, Sterns & Poggenb. | Poaceae | 8 |
| Eragrostis pectinacea | (Michx.) Nees | Poaceae | 8 |
| Eremocarya micrantha | (Torr.) Greene | Boraginaceae | 8 |
| Eremogone aculeata | (S.Watson) Ikonn. | Caryophyllaceae | 8 |
| Eremogone capillaris | (Poir.) Fenzl | Caryophyllaceae | 8 |
| Eremogone congesta | (Nutt.) Ikonn. | Caryophyllaceae | 8 |
| Eremogone franklinii | (Douglas ex Hook.) R.L.Hartm. & Rabeler | Caryophyllaceae | 8 |
| Eremogone kingii | (S.Watson) Ikonn. | Caryophyllaceae | 8 |
| Eremogone pumicola | (Coville & Leiberg) Ikonn. | Caryophyllaceae | 8 |
| Eremothera boothii | (Douglas) W.L.Wagner & Hoch | Onagraceae | 8 |
| Eriastrum signatum | D.Gowen | Polemoniaceae | 8 |
| Eriastrum wilcoxii | (A.Nelson) H.Mason | Polemoniaceae | 8 |
| Ericameria arborescens | (A.Gray) Greene | Asteraceae | 8 |
| Ericameria bloomeri | J.F.Macbr. | Asteraceae | 8 |
| Ericameria discoidea | (Nutt.) G.L.Nesom | Asteraceae | 8 |
| Ericameria greenei | (A.Gray) G.L.Nesom | Asteraceae | 8 |
| Ericameria nana | Nutt. | 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 |
| Ericameria suffruticosa | (Nutt.) G.L.Nesom | Asteraceae | 8 |
| Erigeron acris | L. | Asteraceae | 8 |
| Erigeron aliceae | Howell | Asteraceae | 8 |
| Erigeron annuus | (L.) Desf. | Asteraceae | 8 |
| Erigeron aphanactis | Greene | Asteraceae | 8 |
| Erigeron aureus | Greene | Asteraceae | 8 |
| Erigeron bloomeri | A.Gray | Asteraceae | 8 |
| Erigeron canadensis | L. | Asteraceae | 8 |
| Erigeron cervinus | Greene | Asteraceae | 8 |
| Erigeron compositus | Pursh | Asteraceae | 8 |
| Erigeron divergens | Torr. & A.Gray | Asteraceae | 8 |
| Erigeron eatonii | A.Gray | Asteraceae | 8 |
| Erigeron elegantulus | Greene | Asteraceae | 8 |
| Erigeron filifolius | Nutt. | Asteraceae | 8 |
| Erigeron flagellaris | A.Gray | Asteraceae | 8 |
| Erigeron foliosus | Nutt. | Asteraceae | 8 |
| Erigeron glacialis | (Nutt.) A.Nelson | Asteraceae | 8 |
| Erigeron glaucus | Ker Gawl. | Asteraceae | 8 |
| Erigeron inornatus | A.Gray | Asteraceae | 8 |
| Erigeron klamathensis | (G.L.Nesom) G.L.Nesom | Asteraceae | 8 |
| Erigeron latus | (A.Nelson & J.F.Macbr.) Cronquist | Asteraceae | 8 |
| Erigeron linearis | (Hook.) Piper | Asteraceae | 8 |
| Erigeron lonchophyllus | Hook. | Asteraceae | 8 |
| Erigeron nivalis | Nutt. | Asteraceae | 8 |
| Erigeron peregrinus | Greene | Asteraceae | 8 |
| Erigeron petrophilus | Greene | Asteraceae | 8 |
| Erigeron philadelphicus | L. | Asteraceae | 8 |
| Erigeron poliospermus | A.Gray | Asteraceae | 8 |
| Erigeron pumilus | Nutt. | Asteraceae | 8 |
| Erigeron speciosus | (Lindl.) DC. | Asteraceae | 8 |
| Erigeron strigosus | Muhl. ex Willd. | Asteraceae | 8 |
| Erigeron tener | A.Gray | Asteraceae | 8 |
| Eriocoma hymenoides | (Roem. & Schult.) Rydb. | Poaceae | 8 |
| Eriocoma nelsonii | (Scribn.) Romasch. | Poaceae | 8 |
| Eriocoma occidentalis | (Thurb. ex S.Watson) Romasch. | Poaceae | 8 |
| Eriocoma pinetorum | (M.E.Jones) Romasch. | Poaceae | 8 |
| Eriocoma thurberiana | (Piper) Romasch. | Poaceae | 8 |
| Eriocoma webberi | Thurb. | Poaceae | 8 |
| Eriodictyon californicum | (Hook. & Arn.) Torr. | Namaceae | 8 |
| Eriogonum baileyi | S.Watson | Polygonaceae | 8 |
| Eriogonum caespitosum | Nutt. | Polygonaceae | 8 |
| Eriogonum cernuum | Nutt. | Polygonaceae | 8 |
| Eriogonum compositum | Douglas ex Benth. | Polygonaceae | 8 |
| Eriogonum douglasii | Benth. | Polygonaceae | 8 |
| Eriogonum elatum | Douglas ex Benth. | Polygonaceae | 8 |
| Eriogonum flavum | Nutt. | Polygonaceae | 8 |
| Eriogonum heracleoides | Nutt. | Polygonaceae | 8 |
| Eriogonum hookeri | S.Watson | Polygonaceae | 8 |
| Eriogonum latifolium | Sm. | Polygonaceae | 8 |
| Eriogonum lobbii | Torr. & A.Gray | Polygonaceae | 8 |
| Eriogonum luteolum | Greene | Polygonaceae | 8 |
| Eriogonum maculatum | A.Heller | Polygonaceae | 8 |
| Eriogonum marifolium | A.Gray | Polygonaceae | 8 |
| Eriogonum nidularium | Coville | Polygonaceae | 8 |
| Eriogonum niveum | Douglas ex Benth. | Polygonaceae | 8 |
| Eriogonum nudum | Douglas ex Benth. | Polygonaceae | 8 |
| Eriogonum ovalifolium | Nutt. | Polygonaceae | 8 |
| Eriogonum pusillum | Torr. & A.Gray | Polygonaceae | 8 |
| Eriogonum pyrolifolium | Hook. | Polygonaceae | 8 |
| Eriogonum roseum | Durand & Hilg. | Polygonaceae | 8 |
| Eriogonum spergulinum | A.Gray | Polygonaceae | 8 |
| Eriogonum sphaerocephalum | Douglas ex Benth. | Polygonaceae | 8 |
| Eriogonum strictum | Benth. | Polygonaceae | 8 |
| Eriogonum thymoides | Benth. | Polygonaceae | 8 |
| Eriogonum umbellatum | Torr. | Polygonaceae | 8 |
| Eriogonum vimineum | Douglas ex Benth. | Polygonaceae | 8 |
| Eriogonum watsonii | Torr. & A.Gray | Polygonaceae | 8 |
| Eriophorum angustifolium | Honck. | Cyperaceae | 8 |
| Eriophorum chamissonis | C.A.Mey. | Cyperaceae | 8 |
| Eriophorum gracile | Roth | Cyperaceae | 8 |
| Eriophyllum lanatum | (Pursh) J.Forbes | Asteraceae | 8 |
| Erocallis triphylla | (S.Watson) Rydb. | Montiaceae | 8 |
| Eryngium articulatum | Hook. | Apiaceae | 8 |
| Eryngium petiolatum | Hook. | Apiaceae | 8 |
| Erysimum arenicola | S.Watson | Brassicaceae | 8 |
| Erysimum capitatum | Greene | Brassicaceae | 8 |
| Erysimum concinnum | Eastw. | Brassicaceae | 8 |
| Erysimum perenne | (S.Watson ex Coville) Abrams | Brassicaceae | 8 |
| Erythranthe alsinoides | (Douglas ex Benth.) G.L.Nesom & N.S.Fraga | Phrymaceae | 8 |
| Erythranthe arvensis | (Greene) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe breweri | (Greene) G.L.Nesom & N.S.Fraga | Phrymaceae | 8 |
| Erythranthe cardinalis | (Douglas ex Benth.) Spach | Phrymaceae | 8 |
| Erythranthe decora | (A.L.Grant) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe dentata | (Nutt. ex Benth.) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe floribunda | (Lindl.) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe grandis | (Greene) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe guttata | (DC.) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe lewisii | (Pursh) G.L.Nesom & N.S.Fraga | Phrymaceae | 8 |
| Erythranthe microphylla | (Benth.) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe moschata | (Douglas ex Lindl.) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe nasuta | (Greene) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe primuloides | (Benth.) G.L.Nesom & N.S.Fraga | Phrymaceae | 8 |
| Erythranthe ptilota | G.L.Nesom | Phrymaceae | 8 |
| Erythranthe pulsiferae | (A.Gray) G.L.Nesom | Phrymaceae | 8 |
| Erythranthe suksdorfii | (A.Gray) N.S.Fraga | Phrymaceae | 8 |
| Erythranthe tilingii | (Regel) G.L.Nesom | Phrymaceae | 8 |
| Erythronium citrinum | S.Watson | Liliaceae | 8 |
| Erythronium grandiflorum | Pursh | Liliaceae | 8 |
| Erythronium hendersonii | S.Watson | Liliaceae | 8 |
| Erythronium klamathense | Applegate | Liliaceae | 8 |
| Erythronium montanum | S.Watson | Liliaceae | 8 |
| Erythronium oregonum | Applegate | Liliaceae | 8 |
| Erythronium revolutum | Sm. | Liliaceae | 8 |
| Eschscholzia caespitosa | Benth. | Papaveraceae | 8 |
| Eschscholzia californica | Cham. | Papaveraceae | 8 |
| Euonymus occidentalis | Nutt. ex Torr. | Celastraceae | 8 |
| Euphorbia crenulata | Engelm. | Euphorbiaceae | 8 |
| Euphorbia glyptosperma | Engelm. | Euphorbiaceae | 8 |
| Euphorbia serpillifolia | Pers. | Euphorbiaceae | 8 |
| Euphorbia spathulata | Lam. | Euphorbiaceae | 8 |
| Eurybia conspicua | (Lindl.) G.L.Nesom | Asteraceae | 8 |
| Eurybia integrifolia | (Nutt.) G.L.Nesom | Asteraceae | 8 |
| Eurybia radulina | (A.Gray) G.L.Nesom | Asteraceae | 8 |
| Euthamia occidentalis | Nutt. | Asteraceae | 8 |
| Festuca brachyphylla | Schult. & Schult.f. | Poaceae | 8 |
| Festuca californica | Vasey | Poaceae | 8 |
| Festuca idahoensis | Elmer | Poaceae | 8 |
| Festuca kingii | (S.Watson) Cassidy | Poaceae | 8 |
| Festuca microstachys | Nutt. | Poaceae | 8 |
| Festuca occidentalis | Hook. | Poaceae | 8 |
| Festuca octoflora | Walter | Poaceae | 8 |
| Festuca rubra | L. | Poaceae | 8 |
| Floerkea proserpinacoides | Willd. | Limnanthaceae | 8 |
| Fragaria cascadensis | K.E.Hummer | Rosaceae | 8 |
| Fragaria vesca | L. | Rosaceae | 8 |
| Fragaria virginiana | Mill. | Rosaceae | 8 |
| Frangula californica | (Eschsch.) A.Gray | Rhamnaceae | 8 |
| Frangula purshiana | (DC.) A.Gray ex J.G.Cooper | Rhamnaceae | 8 |
| Frasera albicaulis | Griseb. | Gentianaceae | 8 |
| Frasera speciosa | Douglas ex Griseb. | Gentianaceae | 8 |
| Fraxinus latifolia | Benth. | Oleaceae | 8 |
| Fritillaria affinis | (Schult. & Schult.f.) Sealy | Liliaceae | 8 |
| Fritillaria atropurpurea | Nutt. | Liliaceae | 8 |
| Fritillaria camschatcensis | (L.) Ker Gawl. | Liliaceae | 8 |
| Fritillaria eastwoodiae | R.M.Macfarl. | Liliaceae | 8 |
| Fritillaria glauca | Greene | Liliaceae | 8 |
| Fritillaria pudica | (Pursh) Spreng. | Liliaceae | 8 |
| Fritillaria purdyi | Eastw. | Liliaceae | 8 |
| Fritillaria recurva | Benth. | Liliaceae | 8 |
| Gagea serotina | (L.) Ker Gawl. | Liliaceae | 8 |
| Gaillardia aristata | Pursh | Asteraceae | 8 |
| Galinsoga quadriradiata | Ruiz & Pav. | Asteraceae | 8 |
| Galium kamtschaticum | Steller ex Schult. & Schult.f. | Rubiaceae | 8 |
| Galium mexicanum | Kunth | Rubiaceae | 8 |
| Galium porrigens | Dempster | Rubiaceae | 8 |
| Galium serpenticum | Dempster | Rubiaceae | 8 |
| Galium trifidum | L. | Rubiaceae | 8 |
| Galium triflorum | Michx. | Rubiaceae | 8 |
| Gamochaeta ustulata | (Nutt.) Holub | Asteraceae | 8 |
| Garrya buxifolia | A.Gray | Garryaceae | 8 |
| Garrya elliptica | Douglas ex Lindl. | Garryaceae | 8 |
| Garrya fremontii | Torr. | Garryaceae | 8 |
| Gaultheria humifusa | (Graham) Rydb. | Ericaceae | 8 |
| Gaultheria ovatifolia | A.Gray | Ericaceae | 8 |
| Gaultheria shallon | Pursh | Ericaceae | 8 |
| Gayophytum ramosissimum | Torr. & A.Gray | Onagraceae | 8 |
| Gentiana affinis | Griseb. | Gentianaceae | 8 |
| Gentiana calycosa | Griseb. | Gentianaceae | 8 |
| Gentiana newberryi | A.Gray | Gentianaceae | 8 |
| Gentiana prostrata | Haenke | Gentianaceae | 8 |
| Gentiana sceptrum | Griseb. | Gentianaceae | 8 |
| Gentiana setigera | A.Gray | Gentianaceae | 8 |
| Gentianopsis simplex | (A.Gray) Iltis | Gentianaceae | 8 |
| Geranium bicknellii | Britton | Geraniaceae | 8 |
| Geranium carolinianum | L. | Geraniaceae | 8 |
| Geranium oreganum | Howell | Geraniaceae | 8 |
| Geranium richardsonii | Fisch. & Trautv. | Geraniaceae | 8 |
| Geranium viscosissimum | Fisch. & C.A.Mey. | Geraniaceae | 8 |
| Geum aleppicum | Jacq. | Rosaceae | 8 |
| Geum macrophyllum | Willd. | Rosaceae | 8 |
| Geum rossii | (R.Br.) Ser. | Rosaceae | 8 |
| Geum triflorum | Pursh | Rosaceae | 8 |
| Gilia brecciarum | M.E.Jones | Polemoniaceae | 8 |
| Gilia capitata | Sims | Polemoniaceae | 8 |
| Gilia inconspicua | (Sm.) Sweet | Polemoniaceae | 8 |
| Gilia millefoliata | Fisch. & C.A.Mey. | Polemoniaceae | 8 |
| Gilia sinuata | Douglas ex Benth. | Polemoniaceae | 8 |
| Githopsis specularioides | Nutt. | Campanulaceae | 8 |
| Glehnia littoralis | (J.G.Cooper) F.Schmidt ex Miq. | Apiaceae | 8 |
| Glossopetalon spinescens | A.Gray | Crossosomataceae | 8 |
| Glyceria borealis | (Nash) Batch. | Poaceae | 8 |
| Glyceria canadensis | (Michx.) Trin. | Poaceae | 8 |
| Glyceria elata | (Nash) M.E.Jones | Poaceae | 8 |
| Glyceria grandis | S.Watson | Poaceae | 8 |
| Glyceria striata | (Lam.) Hitchc. | Poaceae | 8 |
| Glycyrrhiza lepidota | Pursh | Fabaceae | 8 |
| Glyptopleura marginata | D.C.Eaton | Asteraceae | 8 |
| Gnaphalium palustre | Nutt. | Asteraceae | 8 |
| Gnaphalium uliginosum | L. | Asteraceae | 8 |
| Goodyera oblongifolia | Raf. | Orchidaceae | 8 |
| Graphephorum canescens | (Buckley) Röser & Tkach | Poaceae | 8 |
| Graphephorum wolfii | (Vasey) Coult. | Poaceae | 8 |
| Gratiola ebracteata | Benth. ex A.DC. | Plantaginaceae | 8 |
| Gratiola heterosepala | H.Mason & Bacigal. | Plantaginaceae | 8 |
| Gratiola neglecta | Torr. | Plantaginaceae | 8 |
| Grayia spinosa | (Hook.) Moq. | Chenopodiaceae | 8 |
| Grindelia hirsutula | Hook. & Arn. | Asteraceae | 8 |
| Grindelia integrifolia | DC. | Asteraceae | 8 |
| Grindelia squarrosa | (Pursh) Dunal | Asteraceae | 8 |
| Gutierrezia sarothrae | (Pursh) Britton & Rusby | Asteraceae | 8 |
| Gymnocarpium disjunctum | (Rupr.) Ching | Cystopteridaceae | 8 |
| Gymnocarpium dryopteris | (L.) Newman | Cystopteridaceae | 8 |
| Gymnosteris nudicaulis | (Hook. & Arn.) Greene | Polemoniaceae | 8 |
| Gymnosteris parvula | A.Heller | Polemoniaceae | 8 |
| Hackelia californica | I.M.Johnst. | Boraginaceae | 8 |
| Hackelia cusickii | Brand | Boraginaceae | 8 |
| Hackelia floribunda | (Lehm.) I.M.Johnst. | Boraginaceae | 8 |
| Hackelia micrantha | (Eastw.) J.L.Gentry | Boraginaceae | 8 |
| Hackelia mundula | (Jeps.) Ferris | Boraginaceae | 8 |
| Hackelia patens | I.M.Johnst. | Boraginaceae | 8 |
| Halerpestes cymbalaria | Greene | Ranunculaceae | 8 |
| Hamogalium bifolium | (S.Watson) Kadereit & Schneew. | Rubiaceae | 8 |
| Hastingsia alba | (Durand) S.Watson | Asparagaceae | 8 |
| Hastingsia serpentinicola | Becking | Asparagaceae | 8 |
| Hedysarum boreale | Nutt. | Fabaceae | 8 |
| Hedysarum sulphurescens | Rydb. | Fabaceae | 8 |
| Helenium autumnale | L. | Asteraceae | 8 |
| Helenium bigelovii | A.Gray | Asteraceae | 8 |
| Helenium bolanderi | A.Gray | Asteraceae | 8 |
| Helianthella californica | A.Gray | Asteraceae | 8 |
| Helianthella quinquenervis | (Hook.) A.Gray | Asteraceae | 8 |
| Helianthella uniflora | Torr. & A.Gray | Asteraceae | 8 |
| Helianthus bolanderi | A.Gray | Asteraceae | 8 |
| Helianthus cusickii | A.Gray | Asteraceae | 8 |
| Helianthus nuttallii | Torr. & A.Gray | Asteraceae | 8 |
| Helianthus petiolaris | Nutt. | Asteraceae | 8 |
| Heliotropium curassavicum | L. | Heliotropiaceae | 8 |
| Hemitomes congestum | A.Gray | Ericaceae | 8 |
| Hemizonella minima | A.Gray | Asteraceae | 8 |
| Hemizonia congesta | DC. | Asteraceae | 8 |
| Heracleum maximum | W.Bartram | Apiaceae | 8 |
| Hesperevax acaulis | (Kellogg) Greene | Asteraceae | 8 |
| Hesperevax sparsiflora | Greene | Asteraceae | 8 |
| Hesperochiron nanus | (Lindl.) Greene | Hydrophyllaceae | 8 |
| Hesperochiron pumilus | (Griseb.) Porter | Hydrophyllaceae | 8 |
| Hesperostipa comata | (Trin. & Rupr.) Barkworth | Poaceae | 8 |
| Heteranthera dubia | (Jacq.) MacMill. | Pontederiaceae | 8 |
| Heterocodon rariflorus | Nutt. | Campanulaceae | 8 |
| Heuchera chlorantha | Piper | Saxifragaceae | 8 |
| Heuchera cylindrica | Douglas | Saxifragaceae | 8 |
| Heuchera glabra | Willd. ex Roem. & Schult. | Saxifragaceae | 8 |
| Heuchera merriamii | Eastw. | Saxifragaceae | 8 |
| Heuchera micrantha | Douglas ex Lindl. | Saxifragaceae | 8 |
| Heuchera pilosissima | Fisch. & C.A.Mey. | Saxifragaceae | 8 |
| Heuchera rubescens | Torr. | Saxifragaceae | 8 |
| Hieracium albiflorum | Hook. | Asteraceae | 8 |
| Hieracium bolanderi | A.Gray | Asteraceae | 8 |
| Hieracium horridum | Fr. | Asteraceae | 8 |
| Hieracium lachenalii | Suter | Asteraceae | 8 |
| Hieracium scouleri | Hook. | Asteraceae | 8 |
| Hieracium triste | Willd. ex Spreng. | Asteraceae | 8 |
| Hieracium umbellatum | L. | Asteraceae | 8 |
| Hippuris vulgaris | L. | Plantaginaceae | 8 |
| Holodiscus discolor | (Pursh) Maxim. | Rosaceae | 8 |
| Honckenya peploides | (L.) Ehrh. | Caryophyllaceae | 8 |
| Hordeum brachyantherum | Nevski | Poaceae | 8 |
| Hordeum depressum | (Scribn. & J.G.Sm.) Rydb. | Poaceae | 8 |
| Hordeum jubatum | L. | Poaceae | 8 |
| Hosackia crassifolia | Benth. | Fabaceae | 8 |
| Hosackia gracilis | Benth. | Fabaceae | 8 |
| Hosackia oblongifolia | Benth. | Fabaceae | 8 |
| Hosackia pinnata | (Hook.) Abrams | Fabaceae | 8 |
| Hosackia rosea | Eastw. | Fabaceae | 8 |
| Hosackia stipularis | Benth. | Fabaceae | 8 |
| Hulsea algida | A.Gray | Asteraceae | 8 |
| Hulsea nana | A.Gray | Asteraceae | 8 |
| Huperzia miyoshiana | (Makino) Ching | Lycopodiaceae | 8 |
| Huperzia occidentalis | (Clute) Kartesz & Gandhi | Lycopodiaceae | 8 |
| Hydrocotyle ranunculoides | L.f. | Araliaceae | 8 |
| Hydrocotyle umbellata | L. | Araliaceae | 8 |
| Hydrocotyle verticillata | Thunb. | Araliaceae | 8 |
| Hydrophyllum alpestre | A.Nelson & P.B.Kenn. | Hydrophyllaceae | 8 |
| Hydrophyllum capitatum | Douglas ex Benth. | Hydrophyllaceae | 8 |
| Hydrophyllum fendleri | (A.Gray) A.Heller | Hydrophyllaceae | 8 |
| Hydrophyllum occidentale | (S.Watson) A.Gray | Hydrophyllaceae | 8 |
| Hydrophyllum tenuipes | A.Heller | Hydrophyllaceae | 8 |
| Hymenopappus filifolius | Hook. | Asteraceae | 8 |
| Hymenoxys cooperi | Cockerell | Asteraceae | 8 |
| Hymenoxys hoopesii | (A.Gray) Bierner | Asteraceae | 8 |
| Hypericum anagalloides | Cham. & Schltdl. | Hypericaceae | 8 |
| Hypericum majus | (A.Gray) Britton | Hypericaceae | 8 |
| Hypericum scouleri | Hook. | Hypericaceae | 8 |
| Hypopitys monotropa | Crantz | Ericaceae | 8 |
| Idahoa scapigera | (Hook.) A.Nelson & J.F.Macbr. | Brassicaceae | 8 |
| Iliamna bakeri | (Jeps.) Wiggins | Malvaceae | 8 |
| Iliamna rivularis | (Douglas) Greene | Malvaceae | 8 |
| Impatiens ecornuta | Gerry Moore, Zika & Rushworth | Balsaminaceae | 8 |
| Ionactis alpina | (Nutt.) Greene | Asteraceae | 8 |
| Ipomopsis aggregata | (Pursh) V.E.Grant | Polemoniaceae | 8 |
| Ipomopsis congesta | (Hook.) V.E.Grant | Polemoniaceae | 8 |
| Ipomopsis polycladon | (Torr.) V.E.Grant | Polemoniaceae | 8 |
| Ipomopsis tenuituba | (Rydb.) V.E.Grant | Polemoniaceae | 8 |
| Iris chrysophylla | Howell | Iridaceae | 8 |
| Iris douglasiana | Herb. | Iridaceae | 8 |
| Iris missouriensis | Nutt. | Iridaceae | 8 |
| Iris tenax | Douglas ex Lindl. | Iridaceae | 8 |
| Isoetes bolanderi | Engelm. | Isoetaceae | 8 |
| Isoetes echinospora | Durieu | Isoetaceae | 8 |
| Isoetes howellii | Engelm. | Isoetaceae | 8 |
| Isoetes minima | A.A.Eaton | Isoetaceae | 8 |
| Isoetes nuttallii | A.Braun ex Engelm. | Isoetaceae | 8 |
| Isoetes orcuttii | A.A.Eaton | Isoetaceae | 8 |
| Isolepis cernua | (Vahl) Roem. & Schult. | Cyperaceae | 8 |
| Iva axillaris | Pursh | Asteraceae | 8 |
| Jaumea carnosa | (Less.) A.Gray | Asteraceae | 8 |
| Juncus acuminatus | Michx. | Juncaceae | 8 |
| Juncus articulatus | L. | Juncaceae | 8 |
| Juncus balticus | Willd. | Juncaceae | 8 |
| Juncus breweri | Engelm. | Juncaceae | 8 |
| Juncus bufonius | L. | Juncaceae | 8 |
| Juncus drummondii | E.Mey. | Juncaceae | 8 |
| Juncus dudleyi | Wiegand | Juncaceae | 8 |
| Juncus effusus | L. | Juncaceae | 8 |
| Juncus ensifolius | Wikstr. | Juncaceae | 8 |
| Juncus falcatus | E.Mey. | Juncaceae | 8 |
| Juncus gerardi | Loisel. | Juncaceae | 8 |
| Juncus kelloggii | Engelm. | Juncaceae | 8 |
| Juncus marginatus | Rostk. | Juncaceae | 8 |
| Juncus mertensianus | Bong. | Juncaceae | 8 |
| Juncus occidentalis | (Coville) Wiegand | Juncaceae | 8 |
| Juncus parryi | Engelm. | Juncaceae | 8 |
| Juncus patens | E.Mey. | Juncaceae | 8 |
| Juncus phaeocephalus | Engelm. | Juncaceae | 8 |
| Juncus tenuis | Willd. | Juncaceae | 8 |
| Juncus torreyi | Coville | Juncaceae | 8 |
| Juncus tweedyi | Rydb. | Juncaceae | 8 |
| Juniperus communis | L. | Cupressaceae | 8 |
| Juniperus occidentalis | Hook. | Cupressaceae | 8 |
| Juniperus scopulorum | Sarg. | Cupressaceae | 8 |
| Kalmia microphylla | (Hook.) A.Heller | Ericaceae | 8 |
| Kelloggia galioides | Torr. | Rubiaceae | 8 |
| Kirkpatrickia breweri | (D.C.Eaton) Li Bing Zhang, X.M.Zhou & Jing Zhao | Pteridaceae | 8 |
| Koeleria macrantha | (Ledeb.) Schult. | Poaceae | 8 |
| Koeleria spicata | (L.) Barberá, Quintanar, Soreng & P.M.Peterson | Poaceae | 8 |
| Kopsiopsis hookeri | (Walp.) Govaerts | Orobanchaceae | 8 |
| Kopsiopsis strobilacea | (A.Gray) Beck | Orobanchaceae | 8 |
| Krascheninnikovia ceratoides | (L.) Gueldenst. | Chenopodiaceae | 8 |
| Kyhosia bolanderi | (A.Gray) B.G.Baldwin | Asteraceae | 8 |
| Lactuca biennis | (Moench) Fernald | Asteraceae | 8 |
| Lactuca canadensis | L. | Asteraceae | 8 |
| Lactuca ludoviciana | (Nutt.) Riddell | Asteraceae | 8 |
| Lactuca oblongifolia | Nutt. | Asteraceae | 8 |
| Ladeania lanceolata | (Pursh) Reveal & A.N.Egan | Fabaceae | 8 |
| Lagophylla ramosissima | Nutt. | Asteraceae | 8 |
| Langloisia setosissima | (Torr. & A.Gray) Greene | Polemoniaceae | 8 |
| Lappula occidentalis | (S.Watson) Greene | Boraginaceae | 8 |
| Larix occidentalis | Nutt. | Pinaceae | 8 |
| Lasthenia californica | DC. ex Lindl. | Asteraceae | 8 |
| Lasthenia glaberrima | DC. | Asteraceae | 8 |
| Lasthenia maritima | (A.Gray) Ornduff | Asteraceae | 8 |
| Lathyrus delnorticus | C.L.Hitchc. | Fabaceae | 8 |
| Lathyrus holochlorus | (Piper) C.L.Hitchc. | Fabaceae | 8 |
| Lathyrus japonicus | Willd. | Fabaceae | 8 |
| Lathyrus lanszwertii | Kellogg | Fabaceae | 8 |
| Lathyrus littoralis | (Nutt.) Endl. ex Walp. | Fabaceae | 8 |
| Lathyrus nevadensis | S.Watson | Fabaceae | 8 |
| Lathyrus palustris | L. | Fabaceae | 8 |
| Lathyrus pauciflorus | Fernald | Fabaceae | 8 |
| Lathyrus polyphyllus | Nutt. | Fabaceae | 8 |
| Lathyrus sulphureus | W.H.Brewer ex A.Gray | Fabaceae | 8 |
| Lathyrus vestitus | Nutt. | Fabaceae | 8 |
| Layia glandulosa | (Hook.) Hook. & Arn. | Asteraceae | 8 |
| Leersia oryzoides | (L.) Sw. | Poaceae | 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 acutidens | (A.Gray) Howell | Brassicaceae | 8 |
| Lepidium densiflorum | Schrad. | Brassicaceae | 8 |
| Lepidium montanum | Nutt. | Brassicaceae | 8 |
| Lepidium nitidum | Nutt. | Brassicaceae | 8 |
| Lepidium oblongum | Small | Brassicaceae | 8 |
| Lepidium strictum | (S.Watson) Rattan ex B.L.Rob. | Brassicaceae | 8 |
| Lepidium virginicum | L. | Brassicaceae | 8 |
| Leptarrhena pyrolifolia | (D.Don) Ser. | Saxifragaceae | 8 |
| Leptosiphon bicolor | Nutt. | Polemoniaceae | 8 |
| Leptosiphon bolanderi | (A.Gray) J.M.Porter & L.A.Johnson | Polemoniaceae | 8 |
| Leptosiphon ciliatus | (Benth.) Jeps. | Polemoniaceae | 8 |
| Leptosiphon liniflorus | (Benth.) J.M.Porter & L.A.Johnson | Polemoniaceae | 8 |
| Leptosiphon nuttallii | (A.Gray) J.M.Porter & L.A.Johnson | Polemoniaceae | 8 |
| Leptosiphon septentrionalis | (H.Mason) J.M.Porter & L.A.Johnson | Polemoniaceae | 8 |
| Leucocrinum montanum | Nutt. ex A.Gray | Asparagaceae | 8 |
| Leucophysalis nana | (A.Gray) Averett | Solanaceae | 8 |
| Leucothoe davisiae | Torr. ex A.Gray | Ericaceae | 8 |
| Lewisia columbiana | (Howell ex A.Gray) B.L.Rob. | Montiaceae | 8 |
| Lewisia cotyledon | (S.Watson) B.L.Rob. | Montiaceae | 8 |
| Lewisia leeana | (Porter) B.L.Rob. | Montiaceae | 8 |
| Lewisia nevadensis | (A.Gray) B.L.Rob. | Montiaceae | 8 |
| Lewisia oppositifolia | (S.Watson) B.L.Rob. | Montiaceae | 8 |
| Lewisia pygmaea | (A.Gray) B.L.Rob. | Montiaceae | 8 |
| Lewisia rediviva | Pursh | Montiaceae | 8 |
| Leymus cinereus | (Scribn. & Merr.) Á.Löve | Poaceae | 8 |
| Leymus flavescens | (Scribn. & J.G.Sm.) Pilg. | Poaceae | 8 |
| Leymus mollis | (Trin.) Pilg. | Poaceae | 8 |
| Leymus triticoides | (Buckley) Pilg. | Poaceae | 8 |
| Ligusticum grayi | J.M.Coult. & Rose | Apiaceae | 8 |
| Lilaeopsis occidentalis | J.M.Coult. & Rose | Apiaceae | 8 |
| Lilium bolanderi | S.Watson | Liliaceae | 8 |
| Lilium columbianum | Leichtlin | Liliaceae | 8 |
| Lilium kelloggii | Purdy | Liliaceae | 8 |
| Lilium pardalinum | Kellogg | Liliaceae | 8 |
| Lilium washingtonianum | Kellogg | Liliaceae | 8 |
| Limnanthes alba | Hartw. ex Benth. | Limnanthaceae | 8 |
| Limnanthes douglasii | R.Br. | Limnanthaceae | 8 |
| Limonium californicum | (Boiss.) A.Heller | Plumbaginaceae | 8 |
| Limosella aquatica | L. | Plantaginaceae | 8 |
| Linanthus pungens | (Torr.) J.M.Porter & L.A.Johnson | Polemoniaceae | 8 |
| Lindernia dubia | (L.) Pennell | Linderniaceae | 8 |
| Linnaea borealis | L. | Caprifoliaceae | 8 |
| Linum lewisii | Pursh | Linaceae | 8 |
| Linum micranthum | A.Gray | Linaceae | 8 |
| Lithophragma affine | A.Gray | Saxifragaceae | 8 |
| Lithophragma campanulatum | Howell | Saxifragaceae | 8 |
| Lithophragma glabrum | Nutt. | Saxifragaceae | 8 |
| Lithophragma heterophyllum | (Hook. & Arn.) Hook. & Arn. | Saxifragaceae | 8 |
| Lithophragma parviflorum | (Hook.) Nutt. | Saxifragaceae | 8 |
| Lithophragma tenellum | Nutt. | Saxifragaceae | 8 |
| Lithospermum californicum | A.Gray | Boraginaceae | 8 |
| Lithospermum ruderale | Douglas ex Lehm. | Boraginaceae | 8 |
| Lobelia dortmanna | L. | Campanulaceae | 8 |
| Loeflingia squarrosa | Nutt. | Caryophyllaceae | 8 |
| Lomatium ambiguum | (Nutt.) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium bentonitum | K.M.Carlson & Mansfield | Apiaceae | 8 |
| Lomatium bradshawii | (Rose ex Mathias) Mathias & Constance | Apiaceae | 8 |
| Lomatium californicum | (Nutt. ex Torr. & A.Gray) Mathias & Constance | Apiaceae | 8 |
| Lomatium canbyi | (J.M.Coult. & Rose) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium columbianum | Mathias & Constance | Apiaceae | 8 |
| Lomatium cous | (S.Watson) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium dissectum | (Nutt.) Mathias & Constance | Apiaceae | 8 |
| Lomatium donnellii | (J.M.Coult. & Rose) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium engelmannii | Mathias | Apiaceae | 8 |
| Lomatium foeniculaceum | (Nutt.) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium fusiformis | (S.Watson) J.F.Sm. & Mansfield | Apiaceae | 8 |
| Lomatium hallii | (S.Watson) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium hendersonii | (J.M.Coult. & Rose) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium howellii | (S.Watson) Jeps. | Apiaceae | 8 |
| Lomatium klickitatense | J.A.Alexander & Whaley | Apiaceae | 8 |
| Lomatium linearifolium | (S.Watson) J.F.Sm. & Mansfield | Apiaceae | 8 |
| Lomatium martindalei | (J.M.Coult. & Rose) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium multifidum | (Nutt.) R.P.McNeill & Darrach | Apiaceae | 8 |
| Lomatium nevadense | (S.Watson) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium nudicaule | (Nutt.) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium papilioniferum | J.A.Alexander & Whaley | Apiaceae | 8 |
| Lomatium piperi | J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium triternatum | (Pursh) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium utriculatum | (Nutt. ex Torr. & A.Gray) J.M.Coult. & Rose | Apiaceae | 8 |
| Lomatium vaginatum | J.M.Coult. & Rose | Apiaceae | 8 |
| Lonicera caerulea | L. | Caprifoliaceae | 8 |
| Lonicera conjugialis | Kellogg | Caprifoliaceae | 8 |
| Lonicera interrupta | Benth. | Caprifoliaceae | 8 |
| Lonicera involucrata | (Richardson) Banks ex Spreng. | Caprifoliaceae | 8 |
| Lonicera utahensis | S.Watson | Caprifoliaceae | 8 |
| Ludwigia grandiflora | (Michx.) Greuter & Burdet | Onagraceae | 8 |
| Ludwigia hexapetala | (Hook. & Arn.) Zardini, H.Y.Gu & 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 |
| Luetkea pectinata | (Pursh) Kuntze | Rosaceae | 8 |
| Luina hypoleuca | Benth. | Asteraceae | 8 |
| Lupinus affinis | J.Agardh | Fabaceae | 8 |
| Lupinus albicaulis | Douglas | Fabaceae | 8 |
| Lupinus albifrons | Benth. | Fabaceae | 8 |
| Lupinus arbustus | Douglas | Fabaceae | 8 |
| Lupinus argenteus | Pursh | Fabaceae | 8 |
| Lupinus bicolor | Lindl. | Fabaceae | 8 |
| Lupinus brevicaulis | S.Watson | Fabaceae | 8 |
| Lupinus breweri | A.Gray | Fabaceae | 8 |
| Lupinus burkei | S.Watson | Fabaceae | 8 |
| Lupinus caudatus | Kellogg | Fabaceae | 8 |
| Lupinus formosus | Greene | Fabaceae | 8 |
| Lupinus latifolius | Lindl. ex J.Agardh | Fabaceae | 8 |
| Lupinus lepidus | Douglas ex Lindl. | Fabaceae | 8 |
| Lupinus leucophyllus | Douglas ex Lindl. | Fabaceae | 8 |
| Lupinus littoralis | Douglas ex Lindl. | Fabaceae | 8 |
| Lupinus luteolus | Kellogg | Fabaceae | 8 |
| Lupinus microcarpus | Sims | Fabaceae | 8 |
| Lupinus nanus | Douglas ex Benth. | Fabaceae | 8 |
| Lupinus nevadensis | A.Heller | Fabaceae | 8 |
| Lupinus oreganus | A.Heller | Fabaceae | 8 |
| Lupinus polyphyllus | Lindl. | Fabaceae | 8 |
| Lupinus prunophilus | M.E.Jones | Fabaceae | 8 |
| Lupinus pusillus | Pursh | Fabaceae | 8 |
| Lupinus rivularis | Douglas ex Lindl. | Fabaceae | 8 |
| Lupinus saxosus | Howell | Fabaceae | 8 |
| Lupinus sulphureus | Douglas | Fabaceae | 8 |
| Luzula comosa | E.Mey. | Juncaceae | 8 |
| Luzula macrantha | (S.Watson) Zika & B.L.Wilson | Juncaceae | 8 |
| Luzula multiflora | (Ehrh.) Lej. | Juncaceae | 8 |
| Luzula parviflora | (Ehrh.) Desv. | Juncaceae | 8 |
| Luzula spicata | (L.) DC. | Juncaceae | 8 |
| Luzula subsessilis | (S.Watson) Buchenau | Juncaceae | 8 |
| Lycopodiella inundata | (L.) Holub | Lycopodiaceae | 8 |
| Lycopodium clavatum | L. | Lycopodiaceae | 8 |
| Lycopodium lagopus | Zinserl. ex Kuzen. | Lycopodiaceae | 8 |
| Lycopus americanus | Muhl. ex W.P.C.Barton | Lamiaceae | 8 |
| Lycopus asper | Greene | Lamiaceae | 8 |
| Lysichiton americanus | Hultén & H.St.John | Araceae | 8 |
| Lysimachia ciliata | L. | Primulaceae | 8 |
| Lysimachia europaea | (L.) U.Manns & Anderb. | Primulaceae | 8 |
| Lysimachia latifolia | (Hook.) Cholewa | Primulaceae | 8 |
| Lysimachia maritima | (L.) Galasso, Banfi & Soldano | Primulaceae | 8 |
| Lysimachia minima | (L.) U.Manns & Anderb. | Primulaceae | 8 |
| Lysimachia thyrsiflora | L. | Primulaceae | 8 |
| Madia citriodora | Greene | Asteraceae | 8 |
| Madia elegans | D.Don | Asteraceae | 8 |
| Madia exigua | (Sm.) Greene | Asteraceae | 8 |
| Madia glomerata | Hook. | Asteraceae | 8 |
| Madia gracilis | (Sm.) D.D.Keck & J.C.Clausen ex Applegate | Asteraceae | 8 |
| Madia sativa | Molina | Asteraceae | 8 |
| Maianthemum dilatatum | (Alph.Wood) A.Nelson & J.F.Macbr. | Asparagaceae | 8 |
| Maianthemum racemosum | (L.) Link | Asparagaceae | 8 |
| Maianthemum stellatum | (L.) Link | Asparagaceae | 8 |
| Malacothrix glabrata | (A.Gray ex D.C.Eaton) A.Gray | Asteraceae | 8 |
| Malacothrix sonchoides | (Nutt.) Torr. & A.Gray | Asteraceae | 8 |
| Malacothrix torreyi | A.Gray | Asteraceae | 8 |
| Malus fusca | (Raf.) C.K.Schneid. | Rosaceae | 8 |
| Malvella leprosa | (Ortega) Krapov. | Malvaceae | 8 |
| Marah oregana | (Torr. & A.Gray) Howell | Cucurbitaceae | 8 |
| Marsilea vestita | Hook. & Grev. | Marsileaceae | 8 |
| Matricaria discoidea | DC. | Asteraceae | 8 |
| Meconella oregana | Nutt. | Papaveraceae | 8 |
| Melica bulbosa | Porter & J.M.Coult. | Poaceae | 8 |
| Melica californica | Scribn. | Poaceae | 8 |
| Melica harfordii | Bol. | Poaceae | 8 |
| Melica stricta | Bol. | Poaceae | 8 |
| Melica subulata | (Griseb.) Scribn. | Poaceae | 8 |
| Mentha canadensis | L. | Lamiaceae | 8 |
| Mentzelia albicaulis | (Douglas ex Hook.) Douglas ex Torr. & A.Gray | Loasaceae | 8 |
| Mentzelia congesta | (Nutt.) Torr. & A.Gray | Loasaceae | 8 |
| Mentzelia dispersa | S.Watson | Loasaceae | 8 |
| Mentzelia laevicaulis | (Douglas ex Hook.) Torr. & A.Gray | Loasaceae | 8 |
| Mentzelia montana | (Davidson) Davidson | Loasaceae | 8 |
| Mentzelia packardiae | Glad | Loasaceae | 8 |
| Mentzelia veatchiana | Kellogg | Loasaceae | 8 |
| Menyanthes trifoliata | L. | Menyanthaceae | 8 |
| Mertensia ciliata | (E.James ex Torr.) G.Don | Boraginaceae | 8 |
| Mertensia longiflora | Greene | Boraginaceae | 8 |
| Mertensia subcordata | Greene | Boraginaceae | 8 |
| Micranthes aprica | (Greene) Small | Saxifragaceae | 8 |
| Micranthes californica | (Greene) Small | Saxifragaceae | 8 |
| Micranthes ferruginea | (Graham) Brouillet & Gornall | Saxifragaceae | 8 |
| Micranthes fragosa | (Suksd. ex Small) Small | Saxifragaceae | 8 |
| Micranthes howellii | Small | Saxifragaceae | 8 |
| Micranthes idahoensis | (Piper) Brouillet & Gornall | Saxifragaceae | 8 |
| Micranthes integrifolia | (Hook.) Small | Saxifragaceae | 8 |
| Micranthes marshallii | Small | Saxifragaceae | 8 |
| Micranthes mertensiana | Rosend. | Saxifragaceae | 8 |
| Micranthes nelsoniana | (D.Don) Small | Saxifragaceae | 8 |
| Micranthes nidifica | (Greene) Small | Saxifragaceae | 8 |
| Micranthes occidentalis | (S.Watson) Small | Saxifragaceae | 8 |
| Micranthes odontoloma | A.Heller | Saxifragaceae | 8 |
| Micranthes oregana | (Howell) Small | Saxifragaceae | 8 |
| Micranthes rufidula | Small | Saxifragaceae | 8 |
| Micranthes tolmiei | (Torr. & A.Gray) Brouillet & Gornall | Saxifragaceae | 8 |
| Micromeria douglasii | Benth. | Lamiaceae | 8 |
| Micropus californicus | Fisch. & C.A.Mey. | Asteraceae | 8 |
| Microseris douglasii | (DC.) Sch.Bip. | Asteraceae | 8 |
| Microseris laciniata | (Hook.) Sch.Bip. | Asteraceae | 8 |
| Microseris nutans | (Hook.) Sch.Bip. | Asteraceae | 8 |
| Microsteris gracilis | (Hook.) Greene | Polemoniaceae | 8 |
| Mimetanthe pilosa | (Benth.) Greene | Phrymaceae | 8 |
| Mirabilis laevis | (Benth.) Curran | Nyctaginaceae | 8 |
| Mitellastra caulescens | (Nutt.) Howell | Saxifragaceae | 8 |
| Moehringia lateriflora | (L.) Fenzl | Caryophyllaceae | 8 |
| Moehringia macrophylla | (Hook.) Fenzl | Caryophyllaceae | 8 |
| Mollugo verticillata | L. | Molluginaceae | 8 |
| Monarda fistulosa | L. | Lamiaceae | 8 |
| Monardella angustifolia | Elvin, Ertter & Mansfield | Lamiaceae | 8 |
| Monardella odoratissima | Benth. | Lamiaceae | 8 |
| Monardella purpurea | Howell | Lamiaceae | 8 |
| Moneses uniflora | (L.) A.Gray | Ericaceae | 8 |
| Monotropa uniflora | L. | Ericaceae | 8 |
| Montia chamissoi | (Ledeb. ex Spreng.) Greene | Montiaceae | 8 |
| Montia fontana | L. | Montiaceae | 8 |
| Montia howellii | S.Watson | Montiaceae | 8 |
| Montia linearis | (Douglas ex Hook.) Greene | Montiaceae | 8 |
| Montia parvifolia | (Moc. ex DC.) Greene | Montiaceae | 8 |
| Muhlenbergia asperifolia | (Nees & Meyen ex Trin.) Parodi | Poaceae | 8 |
| Muhlenbergia glomerata | (Willd.) Trin. | Poaceae | 8 |
| Muhlenbergia mexicana | (L.) Trin. | Poaceae | 8 |
| Muhlenbergia minutissima | (Steud.) Swallen | Poaceae | 8 |
| Muhlenbergia racemosa | (Michx.) Britton, Sterns & Poggenb. | Poaceae | 8 |
| Muhlenbergia richardsonis | (Trin.) Rydb. | Poaceae | 8 |
| Muhlenbergia uniflora | (Muhl.) Fernald | Poaceae | 8 |
| Munroa squarrosa | (Nutt.) Torr. | Poaceae | 8 |
| Myosotis asiatica | (Vestergr.) Schischk. & Serg. | Boraginaceae | 8 |
| Myosotis laxa | Lehm. | Boraginaceae | 8 |
| Myosotis verna | Nutt. | Boraginaceae | 8 |
| Myrica californica | Cham. | Myricaceae | 8 |
| Myrica gale | L. | Myricaceae | 8 |
| Myriophyllum hippuroides | Nutt. ex Torr. & A.Gray | Haloragaceae | 8 |
| Myriophyllum quitense | Kunth | Haloragaceae | 8 |
| Myriophyllum sibiricum | Kom. | Haloragaceae | 8 |
| Myriophyllum verticillatum | L. | Haloragaceae | 8 |
| Myriopteris gracillima | J.Sm. | Pteridaceae | 8 |
| Myriopteris intertexta | (Maxon) Grusz & Windham | Pteridaceae | 8 |
| Nabalus alatus | Hook. | Asteraceae | 8 |
| Najas flexilis | (Willd.) Rostk. & W.L.E.Schmidt | Hydrocharitaceae | 8 |
| Najas guadalupensis | (Spreng.) Magnus | Hydrocharitaceae | 8 |
| Nama aretioides | (Hook. & Arn.) Brand | Namaceae | 8 |
| Nama densa | Lemmon | Namaceae | 8 |
| Nama lobbii | A.Gray | Namaceae | 8 |
| Narthecium californicum | Baker | Nartheciaceae | 8 |
| Navarretia atractyloides | Hook. & Arn. | Polemoniaceae | 8 |
| Navarretia breweri | (A.Gray) Greene | Polemoniaceae | 8 |
| Navarretia capillaris | (Kellogg) Kuntze | Polemoniaceae | 8 |
| Navarretia divaricata | Greene | Polemoniaceae | 8 |
| Navarretia intertexta | Hook. | Polemoniaceae | 8 |
| Navarretia leptalea | (A.Gray) L.A.Johnson | Polemoniaceae | 8 |
| Navarretia leucocephala | Benth. | Polemoniaceae | 8 |
| Navarretia pubescens | (Benth.) Hook. & Arn. | Polemoniaceae | 8 |
| Navarretia squarrosa | (Eschsch.) Hook. & Arn. | Polemoniaceae | 8 |
| Navarretia tagetina | Greene | Polemoniaceae | 8 |
| Nemophila breviflora | A.Gray | Hydrophyllaceae | 8 |
| Nemophila heterophylla | Fisch. & C.A.Mey. | Hydrophyllaceae | 8 |
| Nemophila maculata | Benth. ex Lindl. | Hydrophyllaceae | 8 |
| Nemophila menziesii | Hook. & Arn. | Hydrophyllaceae | 8 |
| Nemophila parviflora | Douglas ex Benth. | Hydrophyllaceae | 8 |
| Nemophila pedunculata | Douglas ex Benth. | Hydrophyllaceae | 8 |
| Neoholmgrenia andina | (Nutt.) W.L.Wagner & Hoch | Onagraceae | 8 |
| Neokochia americana | (S.Watson) G.L.Chu & S.C.Sand. | Chenopodiaceae | 8 |
| Neottia banksiana | (Lindl.) Rchb.f. | Orchidaceae | 8 |
| Neottia borealis | (Morong) Szlach. | Orchidaceae | 8 |
| Neottia convallarioides | (Sw.) Rich. | Orchidaceae | 8 |
| Neottia cordata | (L.) Rich. | Orchidaceae | 8 |
| Nephrophyllidium crista-galli | (Menzies ex Hook.) Gilg | Menyanthaceae | 8 |
| Nestotus stenophyllus | (A.Gray) R.P.Roberts, Urbatsch & Neubig | Asteraceae | 8 |
| Nicotiana attenuata | Torr. ex S.Watson | Solanaceae | 8 |
| Nicotiana quadrivalvis | Pursh | Solanaceae | 8 |
| Nitrophila occidentalis | (Moq.) S.Watson | Chenopodiaceae | 8 |
| Noccaea fendleri | (A.Gray) Holub | Brassicaceae | 8 |
| Nothocalais troximoides | (A.Gray) Greene | Asteraceae | 8 |
| Nothochelone nemorosa | (Douglas ex Lindl.) Straw | Plantaginaceae | 8 |
| Notholithocarpus densiflorus | (Hook. & Arn.) Manos, Cannon & S.H.Oh | Fagaceae | 8 |
| Nuphar polysepala | Engelm. | Nymphaeaceae | 8 |
| Nuttallanthus texanus | (Scheele) D.A.Sutton | Plantaginaceae | 8 |
| Oemleria cerasiformis | (Torr. & A.Gray ex Hook. & Arn.) J.W.Landon | Rosaceae | 8 |
| Oenanthe sarmentosa | Presl ex DC. | Apiaceae | 8 |
| Oenothera biennis | L. | Onagraceae | 8 |
| Oenothera cespitosa | Nutt. | Onagraceae | 8 |
| Oenothera curtiflora | W.L.Wagner & Hoch | Onagraceae | 8 |
| Oenothera deltoides | Torr. & Frém. | Onagraceae | 8 |
| Oenothera elata | Kunth | Onagraceae | 8 |
| Oenothera flava | (A.Nelson) Garrett | Onagraceae | 8 |
| Oenothera pallida | Lindl. | Onagraceae | 8 |
| Oenothera villosa | Thunb. | Onagraceae | 8 |
| Olsynium douglasii | (A.Dietr.) E.P.Bicknell | Iridaceae | 8 |
| Ophioglossum pusillum | Raf. | Ophioglossaceae | 8 |
| Oplopanax horridus | (Sm.) Miq. | Araliaceae | 8 |
| Opuntia fragilis | (Nutt.) Haw. | Cactaceae | 8 |
| Oreocarya glomerata | Greene | Boraginaceae | 8 |
| Oreocarya humilis | (A.Gray) Greene | Boraginaceae | 8 |
| Oreocarya propria | A.Nelson & J.F.Macbr. | Boraginaceae | 8 |
| Oreocarya spiculifera | Piper | Boraginaceae | 8 |
| Oreostemma alpigenum | (Torr. & A.Gray) Greene | Asteraceae | 8 |
| Orobanche californica | Cham. & Schltdl. | Orobanchaceae | 8 |
| Orobanche corymbosa | (Rydb.) Ferris | Orobanchaceae | 8 |
| Orobanche fasciculata | Nutt. | Orobanchaceae | 8 |
| Orobanche pinorum | Geyer ex Hook. | Orobanchaceae | 8 |
| Orobanche uniflora | L. | Orobanchaceae | 8 |
| Orthilia secunda | (L.) House | Ericaceae | 8 |
| Orthocarpus bracteosus | Benth. | Orobanchaceae | 8 |
| Orthocarpus cuspidatus | Greene | Orobanchaceae | 8 |
| Orthocarpus imbricatus | S.Watson | Orobanchaceae | 8 |
| Orthocarpus luteus | Nutt. | Orobanchaceae | 8 |
| Orthocarpus tenuifolius | (Pursh) Benth. | Orobanchaceae | 8 |
| Osmorhiza berteroi | DC. | Apiaceae | 8 |
| Osmorhiza depauperata | Phil. | Apiaceae | 8 |
| Osmorhiza occidentalis | Torr. | Apiaceae | 8 |
| Oxalis oregana | Nutt. | Oxalidaceae | 8 |
| Oxalis pilosa | Nutt. | Oxalidaceae | 8 |
| Oxalis suksdorfii | Trel. | Oxalidaceae | 8 |
| Oxalis trilliifolia | Hook. | Oxalidaceae | 8 |
| Oxybaphus nyctagineus | (Michx.) Sweet | Nyctaginaceae | 8 |
| Oxyria digyna | (L.) Hill | Polygonaceae | 8 |
| Oxytheca dendroidea | Nutt. | Polygonaceae | 8 |
| Oxytropis borealis | DC. | Fabaceae | 8 |
| Oxytropis campestris | (L.) DC. | Fabaceae | 8 |
| Oxytropis deflexa | (Pall.) DC. | Fabaceae | 8 |
| Oxytropis sericea | Nutt. | Fabaceae | 8 |
| Ozomelis stauropetala | (Piper) Rydb. | Saxifragaceae | 8 |
| Ozomelis trifida | (Graham) Rydb. | Saxifragaceae | 8 |
| Packera cana | (Hook.) W.A.Weber & Á.Löve | Asteraceae | 8 |
| Packera macounii | (Greene) W.A.Weber & Á.Löve | Asteraceae | 8 |
| Packera pseudaurea | (Rydb.) W.A.Weber & Á.Löve | Asteraceae | 8 |
| Packera streptanthifolia | (Greene) W.A.Weber & Á.Löve | Asteraceae | 8 |
| Paeonia brownii | Douglas ex Hook. | Paeoniaceae | 8 |
| Panicum capillare | L. | Poaceae | 8 |
| Panicum dichotomiflorum | Michx. | Poaceae | 8 |
| Pappostipa speciosa | (Trin. & Rupr.) Romasch. | Poaceae | 8 |
| Parietaria pensylvanica | Muhl. ex Willd. | Urticaceae | 8 |
| Parnassia fimbriata | K.D.Koenig | Celastraceae | 8 |
| Parnassia palustris | L. | Celastraceae | 8 |
| Parthenocissus quinquefolia | (L.) Planch. | Vitaceae | 8 |
| Paspalum distichum | L. | Poaceae | 8 |
| Paxistima myrsinites | (Pursh) Raf. | Celastraceae | 8 |
| Pectiantia pentandra | (Hook.) Rydb. | Saxifragaceae | 8 |
| Pectocarya penicillata | (Hook. & Arn.) A.DC. | Boraginaceae | 8 |
| Pectocarya pusilla | (A.DC.) A.Gray | Boraginaceae | 8 |
| Pectocarya setosa | A.Gray | Boraginaceae | 8 |
| Pedicularis attollens | A.Gray | Orobanchaceae | 8 |
| Pedicularis bracteosa | Benth. | Orobanchaceae | 8 |
| Pedicularis centranthera | A.Gray | Orobanchaceae | 8 |
| Pedicularis contorta | Benth. | Orobanchaceae | 8 |
| Pedicularis densiflora | Benth. | Orobanchaceae | 8 |
| Pedicularis groenlandica | Retz. | Orobanchaceae | 8 |
| Pedicularis racemosa | Douglas ex Benth. | Orobanchaceae | 8 |
| Pedicularis semibarbata | A.Gray | Orobanchaceae | 8 |
| Pediocactus nigrispinus | (Hochstätter) Hochstätter | Cactaceae | 8 |
| Pellaea andromedifolia | (Kaulf.) Fée | Pteridaceae | 8 |
| Pellaea brachyptera | (T.Moore) Baker | Pteridaceae | 8 |
| Pellaea bridgesii | Hook. | Pteridaceae | 8 |
| Pellaea mucronata | D.C.Eaton | Pteridaceae | 8 |
| Penstemon acuminatus | Douglas ex Lindl. | Plantaginaceae | 8 |
| Penstemon anguineus | Eastw. | Plantaginaceae | 8 |
| Penstemon attenuatus | Douglas | Plantaginaceae | 8 |
| Penstemon azureus | Benth. | Plantaginaceae | 8 |
| Penstemon barrettiae | A.Gray | Plantaginaceae | 8 |
| Penstemon cardwellii | Howell | Plantaginaceae | 8 |
| Penstemon cinicola | D.D.Keck | Plantaginaceae | 8 |
| Penstemon confertus | Douglas | Plantaginaceae | 8 |
| Penstemon davidsonii | Greene | Plantaginaceae | 8 |
| Penstemon deustus | Douglas | Plantaginaceae | 8 |
| Penstemon eriantherus | Nutt. ex Pursh | Plantaginaceae | 8 |
| Penstemon euglaucus | English | Plantaginaceae | 8 |
| Penstemon fruticosus | (Pursh) Greene | Plantaginaceae | 8 |
| Penstemon gairdneri | Hook. | Plantaginaceae | 8 |
| Penstemon gracilentus | A.Gray | Plantaginaceae | 8 |
| Penstemon hesperius | M.E.Peck | Plantaginaceae | 8 |
| Penstemon humilis | Nutt. ex A.Gray | Plantaginaceae | 8 |
| Penstemon janishiae | N.H.Holmgren | Plantaginaceae | 8 |
| Penstemon kingii | S.Watson | Plantaginaceae | 8 |
| Penstemon laetus | A.Gray | Plantaginaceae | 8 |
| Penstemon newberryi | A.Gray | Plantaginaceae | 8 |
| Penstemon parvulus | (A.Gray) Krautter | Plantaginaceae | 8 |
| Penstemon peckii | Pennell | Plantaginaceae | 8 |
| Penstemon pratensis | Greene | Plantaginaceae | 8 |
| Penstemon procerus | Douglas ex Graham | Plantaginaceae | 8 |
| Penstemon richardsonii | Douglas ex Lindl. | Plantaginaceae | 8 |
| Penstemon roezlii | Regel | Plantaginaceae | 8 |
| Penstemon rupicola | (Piper) Howell | Plantaginaceae | 8 |
| Penstemon rydbergii | A.Nelson | Plantaginaceae | 8 |
| Penstemon serrulatus | Menzies ex Sm. | Plantaginaceae | 8 |
| Penstemon speciosus | Douglas | Plantaginaceae | 8 |
| Penstemon venustus | Douglas | Plantaginaceae | 8 |
| Penstemon wilcoxii | Rydb. | Plantaginaceae | 8 |
| Pentagramma triangularis | (Kaulf.) Yatsk., Windham & E.Wollenw. | Pteridaceae | 8 |
| Peraphyllum ramosissimum | Nutt. | Rosaceae | 8 |
| Perideridia bolanderi | A.Nelson & J.F.Macbr. | Apiaceae | 8 |
| Perideridia gairdneri | (Hook. & Arn.) Mathias | Apiaceae | 8 |
| Persicaria amphibia | (L.) Delarbre | Polygonaceae | 8 |
| Persicaria hydropiperoides | (Michx.) Small | Polygonaceae | 8 |
| Persicaria lapathifolia | (L.) Delarbre | Polygonaceae | 8 |
| Persicaria punctata | Small | Polygonaceae | 8 |
| Persicaria vivipara | (L.) Ronse Decr. | Polygonaceae | 8 |
| Petasites frigidus | (L.) Fr. | Asteraceae | 8 |
| Phacelia bicolor | Torr. ex S.Watson | Hydrophyllaceae | 8 |
| Phacelia bolanderi | A.Gray | Hydrophyllaceae | 8 |
| Phacelia californica | Cham. | Hydrophyllaceae | 8 |
| Phacelia corymbosa | Jeps. | Hydrophyllaceae | 8 |
| Phacelia egena | (Brand) Greene ex J.T.Howell | Hydrophyllaceae | 8 |
| Phacelia glandulifera | Piper | Hydrophyllaceae | 8 |
| Phacelia gymnoclada | Torr. ex S.Watson | Hydrophyllaceae | 8 |
| Phacelia hastata | Douglas ex Lehm. | Hydrophyllaceae | 8 |
| Phacelia heterophylla | Pursh | Hydrophyllaceae | 8 |
| Phacelia humilis | Torr. & A.Gray | Hydrophyllaceae | 8 |
| Phacelia hydrophylloides | Torr. ex A.Gray | Hydrophyllaceae | 8 |
| Phacelia inundata | J.T.Howell | Hydrophyllaceae | 8 |
| Phacelia leptosepala | Rydb. | Hydrophyllaceae | 8 |
| Phacelia linearis | (Pursh) Holz. | Hydrophyllaceae | 8 |
| Phacelia lutea | (Hook. & Arn.) J.T.Howell | Hydrophyllaceae | 8 |
| Phacelia malvifolia | Cham. & Schltdl. | Hydrophyllaceae | 8 |
| Phacelia nemoralis | Greene | Hydrophyllaceae | 8 |
| Phacelia procera | A.Gray | Hydrophyllaceae | 8 |
| Phacelia ramosissima | Douglas ex Lehm. | Hydrophyllaceae | 8 |
| Phacelia rattanii | A.Gray | Hydrophyllaceae | 8 |
| Phacelia sericea | (Graham) A.Gray | Hydrophyllaceae | 8 |
| Phalaris arundinacea | L. | Poaceae | 8 |
| Phalaris caroliniana | Walter | Poaceae | 8 |
| Phegopteris connectilis | (Michx.) Watt | Thelypteridaceae | 8 |
| Philadelphus lewisii | Pursh | Hydrangeaceae | 8 |
| Phleum alpinum | L. | Poaceae | 8 |
| Phlox adsurgens | Torr. ex A.Gray | Polemoniaceae | 8 |
| Phlox austromontana | Coville | Polemoniaceae | 8 |
| Phlox diffusa | Benth. | Polemoniaceae | 8 |
| Phlox douglasii | Hook. | Polemoniaceae | 8 |
| Phlox hoodii | Richardson | Polemoniaceae | 8 |
| Phlox longifolia | Nutt. | Polemoniaceae | 8 |
| Phlox multiflora | A.Nelson | Polemoniaceae | 8 |
| Phlox pulvinata | (Wherry) Cronquist | Polemoniaceae | 8 |
| Phlox speciosa | Pursh | Polemoniaceae | 8 |
| Phoenicaulis cheiranthoides | Nutt. | Brassicaceae | 8 |
| Pholistoma membranaceum | (Benth.) Constance | Hydrophyllaceae | 8 |
| Phoradendron densum | Torr. ex Trel. | Santalaceae | 8 |
| Phoradendron juniperinum | Engelm. ex A.Gray | Santalaceae | 8 |
| Phoradendron macrophyllum | (Engelm.) Cockerell | Santalaceae | 8 |
| Phoradendron villosum | (Nutt.) Nutt. ex Engelm. | Santalaceae | 8 |
| Phragmites australis | (Cav.) Steud. | Poaceae | 8 |
| Phyla nodiflora | (L.) Greene | Verbenaceae | 8 |
| Phyllodoce empetriformis | (Sm.) D.Don | Ericaceae | 8 |
| Phyllodoce glanduliflora | (Hook.) Coville | Ericaceae | 8 |
| Phyllospadix scouleri | Hook. | Zosteraceae | 8 |
| Phyllospadix torreyi | S.Watson | Zosteraceae | 8 |
| Physalis longifolia | Nutt. | Solanaceae | 8 |
| Physaria chambersii | Rollins | Brassicaceae | 8 |
| Physaria kingii | (S.Watson) O'Kane & Al-Shehbaz | Brassicaceae | 8 |
| Physocarpus capitatus | (Pursh) Kuntze | Rosaceae | 8 |
| Physocarpus malvaceus | (Greene) Kuntze | Rosaceae | 8 |
| Physostegia parviflora | Nutt. ex A.Gray | Lamiaceae | 8 |
| Phytolacca americana | L. | Phytolaccaceae | 8 |
| Picea breweriana | S.Watson | Pinaceae | 8 |
| Picea engelmannii | Parry ex Engelm. | Pinaceae | 8 |
| Picea sitchensis | (Bong.) Carrière | Pinaceae | 8 |
| Picrothamnus desertorum | Nutt. | Asteraceae | 8 |
| Pilularia americana | A.Br. | Marsileaceae | 8 |
| Pinguicula macroceras | Pall. ex Link | Lentibulariaceae | 8 |
| Pinus albicaulis | Engelm. | Pinaceae | 8 |
| Pinus attenuata | Lemmon | Pinaceae | 8 |
| Pinus contorta | Douglas ex Loudon | Pinaceae | 8 |
| Pinus flexilis | E.James | Pinaceae | 8 |
| Pinus jeffreyi | A.Murray bis & al. | Pinaceae | 8 |
| Pinus lambertiana | Douglas | Pinaceae | 8 |
| Pinus monticola | Douglas ex D.Don | Pinaceae | 8 |
| Pinus ponderosa | Douglas ex C.Lawson | Pinaceae | 8 |
| Piptatheropsis exigua | (Thurb.) Romasch., P.M.Peterson & Soreng | Poaceae | 8 |
| Pityopus californicus | (Eastw.) H.F.Copel. | Ericaceae | 8 |
| Plagiobothrys austiniae | (Greene) I.M.Johnst. | Boraginaceae | 8 |
| Plagiobothrys bracteatus | (Howell) I.M.Johnst. | Boraginaceae | 8 |
| Plagiobothrys figuratus | (Piper) I.M.Johnst. | Boraginaceae | 8 |
| Plagiobothrys fulvus | (Hook. & Arn.) I.M.Johnst. | Boraginaceae | 8 |
| Plagiobothrys greenei | (A.Gray) I.M.Johnst. | Boraginaceae | 8 |
| Plagiobothrys nothofulvus | (A.Gray) A.Gray | Boraginaceae | 8 |
| Plagiobothrys salsus | (Brandegee) I.M.Johnst. | Boraginaceae | 8 |
| Plagiobothrys scouleri | (Hook. & Arn.) I.M.Johnst. | Boraginaceae | 8 |
| Plagiobothrys stipitatus | I.M.Johnst. | Boraginaceae | 8 |
| Plagiobothrys tenellus | (Nutt.) A.Gray | Boraginaceae | 8 |
| Plantago aristata | Michx. | Plantaginaceae | 8 |
| Plantago elongata | Pursh | Plantaginaceae | 8 |
| Plantago erecta | E.Morris | Plantaginaceae | 8 |
| Plantago macrocarpa | Cham. & Schltdl. | Plantaginaceae | 8 |
| Plantago maritima | L. | Plantaginaceae | 8 |
| Plantago patagonica | Jacq. | Plantaginaceae | 8 |
| Plantago subnuda | Pilg. | Plantaginaceae | 8 |
| Plantago virginica | L. | Plantaginaceae | 8 |
| Platanthera aquilonis | Sheviak | Orchidaceae | 8 |
| Platanthera dilatata | (Pursh) Lindl. ex L.C.Beck | Orchidaceae | 8 |
| Platanthera elegans | Lindl. | Orchidaceae | 8 |
| Platanthera elongata | (Rydb.) R.M.Bateman | Orchidaceae | 8 |
| Platanthera ephemerantha | R.M.Bateman | Orchidaceae | 8 |
| Platanthera huronensis | Lindl. | Orchidaceae | 8 |
| Platanthera orbiculata | (Pursh) Lindl. | Orchidaceae | 8 |
| Platanthera sparsiflora | (S.Watson) Schltr. | Orchidaceae | 8 |
| Platanthera stricta | Lindl. | Orchidaceae | 8 |
| Platanthera transversa | (Suksd.) R.M.Bateman | Orchidaceae | 8 |
| Platanthera unalascensis | (Spreng.) Kurtz | Orchidaceae | 8 |
| Platystemon californicus | Benth. | Papaveraceae | 8 |
| Pleiacanthus spinosus | (Nutt.) Rydb. | Asteraceae | 8 |
| Pleuricospora fimbriolata | A.Gray | Ericaceae | 8 |
| Pleuropogon refractus | (A.Gray) Benth. ex Vasey | Poaceae | 8 |
| Poa alpina | L. | Poaceae | 8 |
| Poa cusickii | Vasey | Poaceae | 8 |
| Poa fendleriana | (Steud.) Vasey | Poaceae | 8 |
| Poa glauca | Vahl | Poaceae | 8 |
| Poa macrantha | Vasey | Poaceae | 8 |
| Poa nemoralis | L. | Poaceae | 8 |
| Poa palustris | L. | Poaceae | 8 |
| Poa pratensis | L. | Poaceae | 8 |
| Poa secunda | J.Presl | Poaceae | 8 |
| Poa unilateralis | Scribn. ex Vasey | Poaceae | 8 |
| Poa wheeleri | Vasey | Poaceae | 8 |
| Pogogyne zizyphoroides | Benth. | Lamiaceae | 8 |
| Polemonium californicum | Eastw. | Polemoniaceae | 8 |
| Polemonium carneum | A.Gray | Polemoniaceae | 8 |
| Polemonium micranthum | Benth. | Polemoniaceae | 8 |
| Polemonium occidentale | Greene | Polemoniaceae | 8 |
| Polemonium pulcherrimum | Hook. | Polemoniaceae | 8 |
| Polemonium viscosum | Nutt. | Polemoniaceae | 8 |
| Polyctenium fremontii | Greene | Brassicaceae | 8 |
| Polygonum achoreum | S.F.Blake | Polygonaceae | 8 |
| Polygonum aviculare | L. | Polygonaceae | 8 |
| Polygonum minimum | S.Watson | Polygonaceae | 8 |
| Polygonum paronychia | Cham. & Schltdl. | Polygonaceae | 8 |
| Polygonum spergulariiforme | Meisn. ex Small | Polygonaceae | 8 |
| Polypodium amorphum | Suksd. | Polypodiaceae | 8 |
| Polypodium glycyrrhiza | D.C.Eaton | Polypodiaceae | 8 |
| Polypodium hesperium | Maxon | Polypodiaceae | 8 |
| Polypodium scouleri | Hook. & Grev. | Polypodiaceae | 8 |
| Polypogon interruptus | Kunth | Poaceae | 8 |
| Polystichum andersonii | Hopkins | Dryopteridaceae | 8 |
| Polystichum californicum | (D.C.Eaton) Diels | Dryopteridaceae | 8 |
| Polystichum imbricans | (D.C.Eaton) D.H.Wagner | Dryopteridaceae | 8 |
| Polystichum kruckebergii | W.H.Wagner | Dryopteridaceae | 8 |
| Polystichum lemmonii | Underw. | Dryopteridaceae | 8 |
| Polystichum lonchitis | (L.) Roth | Dryopteridaceae | 8 |
| Polystichum munitum | (Kaulf.) C.Presl | Dryopteridaceae | 8 |
| Polystichum scopulinum | (D.C.Eaton) Maxon | Dryopteridaceae | 8 |
| Populus deltoides | W.Bartram ex Marshall | Salicaceae | 8 |
| Populus tremuloides | Michx. | Salicaceae | 8 |
| Porterella carnosula | (Hook. & Arn.) Torr. | Campanulaceae | 8 |
| Potamogeton alpinus | Balb. | Potamogetonaceae | 8 |
| Potamogeton amplifolius | Tuck. | Potamogetonaceae | 8 |
| Potamogeton berchtoldii | Fieber | Potamogetonaceae | 8 |
| Potamogeton diversifolius | Raf. | Potamogetonaceae | 8 |
| Potamogeton epihydrus | Raf. | Potamogetonaceae | 8 |
| Potamogeton foliosus | Raf. | 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 robbinsii | Oakes | Potamogetonaceae | 8 |
| Potamogeton zosteriformis | Fernald | Potamogetonaceae | 8 |
| Potentilla biennis | Greene | Rosaceae | 8 |
| Potentilla brevifolia | Nutt. | Rosaceae | 8 |
| Potentilla breweri | S.Watson | Rosaceae | 8 |
| Potentilla daucifolia | Greene | Rosaceae | 8 |
| Potentilla douglasii | Greene | Rosaceae | 8 |
| Potentilla drummondii | Lehm. | Rosaceae | 8 |
| Potentilla flabellifolia | Hook. ex Torr. & A.Gray | Rosaceae | 8 |
| Potentilla glaucophylla | Lehm. | Rosaceae | 8 |
| Potentilla gordonii | (Hook.) Greene | Rosaceae | 8 |
| Potentilla gracilis | Douglas ex Hook. | Rosaceae | 8 |
| Potentilla millefolia | Rydb. | Rosaceae | 8 |
| Potentilla newberryi | A.Gray | Rosaceae | 8 |
| Potentilla norvegica | L. | Rosaceae | 8 |
| Potentilla ovina | Macoun | Rosaceae | 8 |
| Potentilla rivalis | Nutt. | Rosaceae | 8 |
| Potentilla supina | L. | Rosaceae | 8 |
| Potentilla tilingii | (Regel) Greene | Rosaceae | 8 |
| Potentilla villosa | Pall. ex Pursh | Rosaceae | 8 |
| Prenanthella exigua | (A.Gray) Rydb. | Asteraceae | 8 |
| Primula conjugens | (Greene) A.R.Mast & Reveal | Primulaceae | 8 |
| Primula hendersonii | (A.Gray) A.R.Mast & Reveal | Primulaceae | 8 |
| Primula jeffreyi | (Van Houtte) A.R.Mast & Reveal | Primulaceae | 8 |
| Primula latiloba | (A.Gray) A.R.Mast & Reveal | Primulaceae | 8 |
| Primula pauciflora | (Greene) A.R.Mast & Reveal | Primulaceae | 8 |
| Primula tetrandra | (Suksd.) A.R.Mast & Reveal | Primulaceae | 8 |
| Proboscidea louisianica | (Mill.) Thell. | Martyniaceae | 8 |
| Prosartes hookeri | Torr. | Liliaceae | 8 |
| Prosartes parvifolia | S.Watson | Liliaceae | 8 |
| Prosartes trachycarpa | S.Watson | Liliaceae | 8 |
| Prunella vulgaris | L. | Lamiaceae | 8 |
| Prunus americana | Marshall | Rosaceae | 8 |
| Prunus emarginata | (Douglas ex Hook.) Eaton | Rosaceae | 8 |
| Prunus pumila | L. | Rosaceae | 8 |
| Prunus subcordata | Benth. | Rosaceae | 8 |
| Prunus virginiana | L. | Rosaceae | 8 |
| Pseudognaphalium californicum | (DC.) Anderb. | Asteraceae | 8 |
| Pseudognaphalium canescens | (DC.) Anderb. | Asteraceae | 8 |
| Pseudognaphalium macounii | (Greene) Kartesz | Asteraceae | 8 |
| Pseudognaphalium stramineum | (Kunth) Anderb. | Asteraceae | 8 |
| Pseudoroegneria spicata | (Pursh) Á.Löve | Poaceae | 8 |
| Pseudotrillium rivale | (S.Watson) S.B.Farmer | Melanthiaceae | 8 |
| Pseudotsuga menziesii | (Mirb.) Franco | Pinaceae | 8 |
| Psilocarphus brevissimus | Nutt. | Asteraceae | 8 |
| Psilocarphus elatior | A.Gray | Asteraceae | 8 |
| Psilocarphus tenellus | Nutt. | Asteraceae | 8 |
| Psorodendron kingii | (S.Watson) Rydb. | Fabaceae | 8 |
| Pteridium aquilinum | (L.) Kuhn | Dennstaedtiaceae | 8 |
| Pterospora andromedea | Nutt. | Ericaceae | 8 |
| Puccinellia lemmonii | (Vasey) Scribn. | Poaceae | 8 |
| Puccinellia nuttalliana | (Schult.) Hitchc. | Poaceae | 8 |
| Pulsatilla occidentalis | (S.Watson) Freyn | Ranunculaceae | 8 |
| Purshia tridentata | (Pursh) DC. | Rosaceae | 8 |
| Pyrola aphylla | Sm. | Ericaceae | 8 |
| Pyrola asarifolia | Michx. | Ericaceae | 8 |
| Pyrola chlorantha | Sw. | Ericaceae | 8 |
| Pyrola minor | L. | Ericaceae | 8 |
| Pyrola picta | Sm. | Ericaceae | 8 |
| Pyrrocoma carthamoides | Hook. | Asteraceae | 8 |
| Quercus chrysolepis | Liebm. | Fagaceae | 8 |
| Quercus garryana | Douglas ex Hook. | Fagaceae | 8 |
| Quercus kelloggii | Newb. | Fagaceae | 8 |
| Quercus sadleriana | R.Br.ter | Fagaceae | 8 |
| Rafinesquia californica | Nutt. | Asteraceae | 8 |
| Raillardella argentea | A.Gray | Asteraceae | 8 |
| Raillardella scaposa | A.Gray | Asteraceae | 8 |
| Rainiera stricta | (Greene) Greene | Asteraceae | 8 |
| Ranunculus alismifolius | Geyer ex Benth. | Ranunculaceae | 8 |
| Ranunculus andersonii | A.Gray | Ranunculaceae | 8 |
| Ranunculus californicus | Benth. | Ranunculaceae | 8 |
| Ranunculus eschscholtzii | Schltdl. | Ranunculaceae | 8 |
| Ranunculus flabellaris | Raf. | Ranunculaceae | 8 |
| Ranunculus flammula | L. | Ranunculaceae | 8 |
| Ranunculus glaberrimus | Hook. | Ranunculaceae | 8 |
| Ranunculus gmelinii | DC. | Ranunculaceae | 8 |
| Ranunculus hebecarpus | Hook. & Arn. | Ranunculaceae | 8 |
| Ranunculus lobbii | (Hiern) A.Gray | Ranunculaceae | 8 |
| Ranunculus macounii | Britton | Ranunculaceae | 8 |
| Ranunculus minimus | E.H.L.Krause | Ranunculaceae | 8 |
| Ranunculus occidentalis | Nutt. | Ranunculaceae | 8 |
| Ranunculus orthorhynchus | Hook. | Ranunculaceae | 8 |
| Ranunculus populago | Greene | Ranunculaceae | 8 |
| Ranunculus sceleratus | L. | Ranunculaceae | 8 |
| Ranunculus trichophyllus | Chaix | Ranunculaceae | 8 |
| Ranunculus uncinatus | D.Don ex G.Don | Ranunculaceae | 8 |
| Rhamnus alnifolia | L'Hér. | Rhamnaceae | 8 |
| Rhamnus crocea | Nutt. | Rhamnaceae | 8 |
| Rhinanthus groenlandicus | Chabert | Orobanchaceae | 8 |
| Rhinotropis californica | (Nutt.) J.R.Abbott | Polygalaceae | 8 |
| Rhodiola integrifolia | Raf. | Crassulaceae | 8 |
| Rhododendron albiflorum | Hook. | Ericaceae | 8 |
| Rhododendron columbianum | (Piper) Harmaja | Ericaceae | 8 |
| Rhododendron groenlandicum | (Oeder) Kron & Judd | Ericaceae | 8 |
| Rhododendron macrophyllum | D.Don ex G.Don | Ericaceae | 8 |
| Rhododendron menziesii | Craven | Ericaceae | 8 |
| Rhododendron occidentale | (Torr. & A.Gray) A.Gray | Ericaceae | 8 |
| Rhus aromatica | Aiton | Anacardiaceae | 8 |
| Rhus glabra | L. | Anacardiaceae | 8 |
| Rhynchospora alba | (L.) Vahl | Cyperaceae | 8 |
| Rhynchospora capitellata | (Michx.) Vahl | Cyperaceae | 8 |
| Rhysopterus plurijugus | J.M.Coult. & Rose | Apiaceae | 8 |
| Ribes acerifolium | Howell | Grossulariaceae | 8 |
| Ribes aureum | Pursh | Grossulariaceae | 8 |
| Ribes bracteosum | Douglas | Grossulariaceae | 8 |
| Ribes cereum | Douglas | Grossulariaceae | 8 |
| Ribes divaricatum | Douglas | Grossulariaceae | 8 |
| Ribes erythrocarpum | Coville & Leiberg | Grossulariaceae | 8 |
| Ribes hudsonianum | Richardson | Grossulariaceae | 8 |
| Ribes inerme | Rydb. | Grossulariaceae | 8 |
| Ribes lacustre | (Pers.) Poir. | Grossulariaceae | 8 |
| Ribes laxiflorum | Pursh | Grossulariaceae | 8 |
| Ribes lobbii | A.Gray | Grossulariaceae | 8 |
| Ribes menziesii | Pursh | Grossulariaceae | 8 |
| Ribes montigenum | McClatchie | Grossulariaceae | 8 |
| Ribes oxyacanthoides | L. | Grossulariaceae | 8 |
| Ribes roezlii | Regel | Grossulariaceae | 8 |
| Ribes sanguineum | Pursh | Grossulariaceae | 8 |
| Ribes triste | Pall. | Grossulariaceae | 8 |
| Ribes velutinum | Greene | Grossulariaceae | 8 |
| Ribes viscosissimum | Pursh | Grossulariaceae | 8 |
| Ribes wolfii | Rothr. | Grossulariaceae | 8 |
| Rigiopappus leptocladus | A.Gray | Asteraceae | 8 |
| Romanzoffia californica | Greene | Hydrophyllaceae | 8 |
| Romanzoffia sitchensis | Bong. | Hydrophyllaceae | 8 |
| Romanzoffia tracyi | Jeps. | Hydrophyllaceae | 8 |
| Rorippa curvipes | Greene | Brassicaceae | 8 |
| Rorippa curvisiliqua | (Hook.) Bessey ex Britton | Brassicaceae | 8 |
| Rorippa palustris | (L.) Besser | Brassicaceae | 8 |
| Rosa bridgesii | Crép. ex Rydb. | Rosaceae | 8 |
| Rosa californica | Cham. & Schltdl. | Rosaceae | 8 |
| Rosa gymnocarpa | Nutt. | Rosaceae | 8 |
| Rosa nutkana | C.Presl | Rosaceae | 8 |
| Rosa pisocarpa | A.Gray | Rosaceae | 8 |
| Rosa spithamea | S.Watson | Rosaceae | 8 |
| Rosa woodsii | Lindl. | Rosaceae | 8 |
| Rotala ramosior | (L.) Koehne | Lythraceae | 8 |
| Rubus arcticus | L. | Rosaceae | 8 |
| Rubus idaeus | L. | Rosaceae | 8 |
| Rubus lasiococcus | A.Gray | Rosaceae | 8 |
| Rubus leucodermis | (Douglas ex Hook.) Douglas ex Torr. & A.Gray | Rosaceae | 8 |
| Rubus nivalis | Douglas ex Hook. | Rosaceae | 8 |
| Rubus parviflorus | Nutt. | Rosaceae | 8 |
| Rubus pedatus | Sm. | Rosaceae | 8 |
| Rubus spectabilis | Pursh | Rosaceae | 8 |
| Rubus ursinus | Cham. & Schltdl. | Rosaceae | 8 |
| Rudbeckia glaucescens | Eastw. | Asteraceae | 8 |
| Rudbeckia hirta | L. | Asteraceae | 8 |
| Rudbeckia occidentalis | Nutt. | Asteraceae | 8 |
| Rumex californicus | Rech.f. | Polygonaceae | 8 |
| Rumex crassus | Rech.f. | Polygonaceae | 8 |
| Rumex maritimus | L. | Polygonaceae | 8 |
| Rumex occidentalis | S.Watson | Polygonaceae | 8 |
| Rumex paucifolius | Nutt. | Polygonaceae | 8 |
| Rumex transitorius | Rech.f. | Polygonaceae | 8 |
| Rumex triangulivalvis | (Danser) Rech.f. | Polygonaceae | 8 |
| Rumex venosus | Pursh | Polygonaceae | 8 |
| Rupertia physodes | (Douglas) J.W.Grimes | Fabaceae | 8 |
| Ruppia cirrhosa | (Petagna) Grande | Ruppiaceae | 8 |
| Ruppia maritima | L. | Ruppiaceae | 8 |
| Sabulina austromontana | (S.J.Wolf & Packer) Dillenb. & Kadereit | Caryophyllaceae | 8 |
| Sabulina californica | (A.Gray) Dillenb. & Kadereit | Caryophyllaceae | 8 |
| Sabulina douglasii | (Fenzl ex Torr. & A.Gray) Dillenb. & Kadereit | Caryophyllaceae | 8 |
| Sabulina nuttallii | (Pax) Dillenb. & Kadereit | Caryophyllaceae | 8 |
| Sabulina rubella | (Wahlenb.) Dillenb. & Kadereit | Caryophyllaceae | 8 |
| Sagina decumbens | (Elliott) Torr. & A.Gray | Caryophyllaceae | 8 |
| Sagina maxima | A.Gray | Caryophyllaceae | 8 |
| Sagina saginoides | (L.) H.Karst. | Caryophyllaceae | 8 |
| Sagittaria cuneata | E.Sheld. | Alismataceae | 8 |
| Sairocarpus kingii | (S.Watson) D.A.Sutton | Plantaginaceae | 8 |
| Sairocarpus vexillocalyculatus | (Kellogg) D.A.Sutton | Plantaginaceae | 8 |
| Salicornia perennis | Mill. | Chenopodiaceae | 8 |
| Salicornia rubra | A.Nelson | Chenopodiaceae | 8 |
| Salix amygdaloides | Andersson | Salicaceae | 8 |
| Salix barclayi | Andersson | Salicaceae | 8 |
| Salix bebbiana | Sarg. | Salicaceae | 8 |
| Salix boothii | Dorn | Salicaceae | 8 |
| Salix brachycarpa | Nutt. | Salicaceae | 8 |
| Salix commutata | Bebb | Salicaceae | 8 |
| Salix drummondiana | Barratt | Salicaceae | 8 |
| Salix eastwoodiae | Cockerell ex A.Heller | Salicaceae | 8 |
| Salix exigua | Nutt. | Salicaceae | 8 |
| Salix geyeriana | Andersson | Salicaceae | 8 |
| Salix glauca | L. | Salicaceae | 8 |
| Salix hookeriana | Barratt ex Hook. | Salicaceae | 8 |
| Salix laevigata | Bebb | Salicaceae | 8 |
| Salix lasiandra | Benth. | Salicaceae | 8 |
| Salix lasiolepis | Benth. | Salicaceae | 8 |
| Salix lutea | Nutt. | Salicaceae | 8 |
| Salix melanopsis | Nutt. | Salicaceae | 8 |
| Salix nivalis | Hook. | Salicaceae | 8 |
| Salix pedicellaris | Pursh | Salicaceae | 8 |
| Salix petrophila | Rydb. | Salicaceae | 8 |
| Salix planifolia | Pursh | Salicaceae | 8 |
| Salix scouleriana | Barratt | Salicaceae | 8 |
| Salix sitchensis | Sanson ex Bong. | Salicaceae | 8 |
| Salix vestita | Pursh | Salicaceae | 8 |
| Salix wolfii | Bebb | Salicaceae | 8 |
| Salvia dorrii | (Kellogg) Abrams | Lamiaceae | 8 |
| Sambucus cerulea | Raf. | Viburnaceae | 8 |
| Sambucus racemosa | L. | Viburnaceae | 8 |
| Samolus parviflorus | Raf. | Primulaceae | 8 |
| Sanguisorba occidentalis | Nutt. | Rosaceae | 8 |
| Sanguisorba officinalis | L. | Rosaceae | 8 |
| Sanguisorba stipulata | Raf. | Rosaceae | 8 |
| Sanicula arctopoides | Hook. & Arn. | Apiaceae | 8 |
| Sanicula bipinnatifida | Douglas | Apiaceae | 8 |
| Sanicula crassicaulis | Poepp. ex DC. | Apiaceae | 8 |
| Sanicula graveolens | Poepp. ex DC. | Apiaceae | 8 |
| Sanicula laciniata | Hook. & Arn. | Apiaceae | 8 |
| Sanicula peckiana | J.F.Macbr. | Apiaceae | 8 |
| Sarcobatus vermiculatus | (Hook.) Torr. | Sarcobataceae | 8 |
| Sarcodes sanguinea | Torr. | Ericaceae | 8 |
| Saussurea americana | Eaton | Asteraceae | 8 |
| Saxifraga adscendens | L. | Saxifragaceae | 8 |
| Saxifraga bronchialis | L. | Saxifragaceae | 8 |
| Saxifraga cespitosa | L. | Saxifragaceae | 8 |
| Saxifraga hyperborea | R.Br. | Saxifragaceae | 8 |
| Saxifraga oppositifolia | L. | Saxifragaceae | 8 |
| Sceptridium multifidum | (S.G.Gmel.) M.Nishida | Ophioglossaceae | 8 |
| Scheuchzeria palustris | L. | Scheuchzeriaceae | 8 |
| Schoenoplectus acutus | (Muhl. ex Bigelow) Á.Löve & D.Löve | Cyperaceae | 8 |
| Schoenoplectus americanus | (Pers.) Volkart | Cyperaceae | 8 |
| Schoenoplectus heterochaetus | (Chase) Soják | Cyperaceae | 8 |
| Schoenoplectus pungens | (Vahl) Palla | Cyperaceae | 8 |
| Schoenoplectus subterminalis | (Torr.) Soják | Cyperaceae | 8 |
| Schoenoplectus tabernaemontani | (C.C.Gmel.) Palla | Cyperaceae | 8 |
| Scirpus congdonii | Britton | Cyperaceae | 8 |
| Scirpus cyperinus | (L.) Kunth | Cyperaceae | 8 |
| Scirpus microcarpus | J.Presl & C.Presl | Cyperaceae | 8 |
| Scirpus pendulus | Muhl. | Cyperaceae | 8 |
| Scoliopus hallii | S.Watson | Liliaceae | 8 |
| Scrophularia californica | Cham. & Schltdl. | Scrophulariaceae | 8 |
| Scrophularia lanceolata | Pursh | Scrophulariaceae | 8 |
| Scutellaria angustifolia | Pursh | Lamiaceae | 8 |
| Scutellaria antirrhinoides | Benth. | Lamiaceae | 8 |
| Scutellaria galericulata | L. | Lamiaceae | 8 |
| Scutellaria lateriflora | L. | Lamiaceae | 8 |
| Scutellaria nana | A.Gray | Lamiaceae | 8 |
| Scutellaria tuberosa | Benth. | Lamiaceae | 8 |
| Sedum debile | S.Watson | Crassulaceae | 8 |
| Sedum divergens | S.Watson | Crassulaceae | 8 |
| Sedum lanceolatum | Torr. | Crassulaceae | 8 |
| Sedum laxum | (Britton) A.Berger | Crassulaceae | 8 |
| Sedum oreganum | Nutt. | Crassulaceae | 8 |
| Sedum oregonense | (S.Watson) M.Peck | Crassulaceae | 8 |
| Sedum pumilum | Benth. | Crassulaceae | 8 |
| Sedum radiatum | S.Watson | Crassulaceae | 8 |
| Sedum spathulifolium | Hook. | Crassulaceae | 8 |
| Sedum stenopetalum | Pursh | Crassulaceae | 8 |
| Selaginella douglasii | (Hook. & Grev.) Spring | Selaginellaceae | 8 |
| Selaginella oregana | D.C.Eaton | Selaginellaceae | 8 |
| Selaginella scopulorum | Maxon | Selaginellaceae | 8 |
| Selaginella wallacei | Hieron. | Selaginellaceae | 8 |
| Selaginella watsonii | Underw. | Selaginellaceae | 8 |
| Senecio aronicoides | DC. | Asteraceae | 8 |
| Senecio crassulus | A.Gray | Asteraceae | 8 |
| Senecio fremontii | Torr. & A.Gray | Asteraceae | 8 |
| Senecio hydrophiloides | Rydb. | Asteraceae | 8 |
| Senecio hydrophilus | Nutt. | Asteraceae | 8 |
| Senecio integerrimus | Nutt. | Asteraceae | 8 |
| Senecio serra | Hook. | Asteraceae | 8 |
| Senecio triangularis | Hook. | Asteraceae | 8 |
| Sequoia sempervirens | (D.Don) Endl. | Cupressaceae | 8 |
| Sericocarpus oregonensis | Nutt. | Asteraceae | 8 |
| Sericocarpus rigidus | Lindl. | Asteraceae | 8 |
| Setaria parviflora | (Poir.) Kerguélen | Poaceae | 8 |
| Shepherdia argentea | (Pursh) Nutt. | Elaeagnaceae | 8 |
| Shepherdia canadensis | (L.) Nutt. | Elaeagnaceae | 8 |
| Sibbaldia procumbens | L. | Rosaceae | 8 |
| Sidalcea campestris | Greene | Malvaceae | 8 |
| Sidalcea hendersonii | S.Watson | Malvaceae | 8 |
| Sidalcea hirtipes | C.L.Hitchc. | Malvaceae | 8 |
| Sidalcea malviflora | (DC.) A.Gray | Malvaceae | 8 |
| Sidalcea nelsoniana | Piper | Malvaceae | 8 |
| Sidalcea neomexicana | A.Gray | Malvaceae | 8 |
| Sidalcea oregana | (Nutt. ex Torr. & A.Gray) A.Gray | Malvaceae | 8 |
| Silene acaulis | (L.) Jacq. | Caryophyllaceae | 8 |
| Silene antirrhina | L. | Caryophyllaceae | 8 |
| Silene bernardina | S.Watson | Caryophyllaceae | 8 |
| Silene campanulata | S.Watson | Caryophyllaceae | 8 |
| Silene douglasii | Hook. | Caryophyllaceae | 8 |
| Silene hookeri | Nutt. | Caryophyllaceae | 8 |
| Silene lemmonii | S.Watson | Caryophyllaceae | 8 |
| Silene menziesii | Hook. | Caryophyllaceae | 8 |
| Silene oregana | S.Watson | Caryophyllaceae | 8 |
| Silene parryi | (S.Watson) C.L.Hitchc. & Maguire | Caryophyllaceae | 8 |
| Silene scouleri | Hook. | Caryophyllaceae | 8 |
| Silene verecunda | S.Watson | Caryophyllaceae | 8 |
| Sisyrinchium bellum | S.Watson | Iridaceae | 8 |
| Sisyrinchium californicum | (Ker Gawl.) W.T.Aiton | Iridaceae | 8 |
| Sisyrinchium halophilum | Greene | Iridaceae | 8 |
| Sisyrinchium idahoense | E.P.Bicknell | Iridaceae | 8 |
| Sium suave | Walter | Apiaceae | 8 |
| Smelowskia americana | Rydb. | Brassicaceae | 8 |
| Smilax californica | (A.DC.) A.Gray | Smilacaceae | 8 |
| Solanum americanum | Mill. | Solanaceae | 8 |
| Solanum triflorum | Nutt. | Solanaceae | 8 |
| Solanum umbelliferum | Eschsch. | Solanaceae | 8 |
| Solidago elongata | Nutt. | Asteraceae | 8 |
| Solidago gigantea | Aiton | Asteraceae | 8 |
| Solidago lepida | DC. | Asteraceae | 8 |
| Solidago missouriensis | Nutt. | Asteraceae | 8 |
| Solidago multiradiata | Aiton | Asteraceae | 8 |
| Solidago simplex | Kunth | Asteraceae | 8 |
| Solidago spathulata | DC. | Asteraceae | 8 |
| Solidago velutina | DC. | Asteraceae | 8 |
| Sorbus californica | Greene | Rosaceae | 8 |
| Sorbus scopulina | Greene | Rosaceae | 8 |
| Sorbus sitchensis | M.Roem. | Rosaceae | 8 |
| Sparganium angustifolium | Michx. | Typhaceae | 8 |
| Sparganium emersum | Rehmann | Typhaceae | 8 |
| Sparganium eurycarpum | Engelm. | Typhaceae | 8 |
| Sparganium natans | L. | Typhaceae | 8 |
| Spergularia canadensis | (Pers.) G.Don | Caryophyllaceae | 8 |
| Spergularia macrotheca | (Hornem. ex Cham. & Schltdl.) Heynh. | Caryophyllaceae | 8 |
| Spergularia marina | (L.) Besser | Caryophyllaceae | 8 |
| Sphaeralcea grossulariifolia | (Hook. & Arn.) Rydb. | Malvaceae | 8 |
| Sphaeralcea munroana | (Douglas ex Lindl.) Spach | Malvaceae | 8 |
| Sphenopholis intermedia | (Rydb.) Rydb. | Poaceae | 8 |
| Sphenopholis obtusata | (Michx.) Scribn. | Poaceae | 8 |
| Spinulum annotinum | (L.) A.Haines | Lycopodiaceae | 8 |
| Spiraea douglasii | Hook. | Rosaceae | 8 |
| Spiraea lucida | Douglas ex Greene | Rosaceae | 8 |
| Spiraea splendens | Baumann ex K.Koch | Rosaceae | 8 |
| Spiranthes porrifolia | Lindl. | Orchidaceae | 8 |
| Spiranthes romanzoffiana | Cham. | 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 hookerianus | P.M.Peterson & Saarela | Poaceae | 8 |
| Sporobolus michauxianus | (Hitchc.) P.M.Peterson & Saarela | Poaceae | 8 |
| Stachys ajugoides | Benth. | Lamiaceae | 8 |
| Stachys chamissonis | Benth. | Lamiaceae | 8 |
| Stachys mexicana | Benth. | Lamiaceae | 8 |
| Stachys pilosa | Nutt. | Lamiaceae | 8 |
| Stachys rigida | Nutt. ex Benth. | Lamiaceae | 8 |
| Stanleya pinnata | (Pursh) Britton | Brassicaceae | 8 |
| Stanleya viridiflora | Nutt. | Brassicaceae | 8 |
| Stellaria borealis | Bigelow | Caryophyllaceae | 8 |
| Stellaria crispa | Cham. & Schltdl. | Caryophyllaceae | 8 |
| Stellaria humifusa | Rottb. | Caryophyllaceae | 8 |
| Stellaria longifolia | Muhl. ex Willd. | Caryophyllaceae | 8 |
| Stellaria longipes | Goldie | Caryophyllaceae | 8 |
| Stellaria nitens | Nutt. | Caryophyllaceae | 8 |
| Stenotus acaulis | (Nutt.) Nutt. | Asteraceae | 8 |
| Stephanomeria elata | Nutt. | Asteraceae | 8 |
| Stephanomeria exigua | Nutt. | Asteraceae | 8 |
| Stephanomeria lactucina | A.Gray | Asteraceae | 8 |
| Stephanomeria pauciflora | (Torr.) A.Nelson | Asteraceae | 8 |
| Stephanomeria virgata | Benth. | Asteraceae | 8 |
| Streptanthus cordatus | Nutt. | Brassicaceae | 8 |
| Streptanthus crassicaulis | Torr. | Brassicaceae | 8 |
| Streptanthus glandulosus | Hook. | Brassicaceae | 8 |
| Streptanthus howellii | S.Watson | Brassicaceae | 8 |
| Streptanthus lasiophyllus | Hook. & Arn. ex Hoover | Brassicaceae | 8 |
| Streptanthus longirostris | (S.Watson) S.Watson | Brassicaceae | 8 |
| Streptanthus pilosus | Jeps. | Brassicaceae | 8 |
| Streptanthus tortuosus | Kellogg | Brassicaceae | 8 |
| Streptopus amplexifolius | (L.) DC. | Liliaceae | 8 |
| Streptopus lanceolatus | (Aiton) Reveal | Liliaceae | 8 |
| Struthiopteris spicant | (L.) Weiss | Blechnaceae | 8 |
| Stuckenia filiformis | (Pers.) Börner | Potamogetonaceae | 8 |
| Stuckenia pectinata | (L.) Börner | Potamogetonaceae | 8 |
| Stylocline psilocarphoides | M.Peck | Asteraceae | 8 |
| Suaeda calceoliformis | (Hook.) Moq. | Chenopodiaceae | 8 |
| Suaeda nigra | (Raf.) J.F.Macbr. | Chenopodiaceae | 8 |
| Subularia aquatica | L. | Brassicaceae | 8 |
| Suksdorfia ranunculifolia | (Hook.) Engl. | Saxifragaceae | 8 |
| Suksdorfia violacea | A.Gray | Saxifragaceae | 8 |
| Swertia perennis | L. | Gentianaceae | 8 |
| Symphoricarpos albus | (L.) S.F.Blake | Caprifoliaceae | 8 |
| Symphoricarpos longiflorus | A.Gray | Caprifoliaceae | 8 |
| Symphoricarpos occidentalis | (R.Br.) Hook. | Caprifoliaceae | 8 |
| Symphoricarpos rotundifolius | A.Gray | Caprifoliaceae | 8 |
| Symphyotrichum ascendens | (Lindl.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum campestre | (Nutt.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum chilense | (Nees) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum ciliatum | (Ledeb.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum eatonii | (A.Gray) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum ericoides | (L.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum foliaceum | (Lindl. ex DC.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum frondosum | (Nutt.) G.L.Nesom | Asteraceae | 8 |
| Symphyotrichum hallii | (A.Gray) 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 subspicatum | (Nees) G.L.Nesom | Asteraceae | 8 |
| Tanacetum bipinnatum | Sch.Bip. | Asteraceae | 8 |
| Taraxia ovata | (Nutt.) Small | Onagraceae | 8 |
| Taraxia subacaulis | Rydb. | Onagraceae | 8 |
| Taraxia tanacetifolia | (Torr. & A.Gray) Piper | Onagraceae | 8 |
| Tauschia kelloggii | (A.Gray) J.F.Macbr. | Apiaceae | 8 |
| Tauschia stricklandii | (J.M.Coult. & Rose) Mathias & Constance | Apiaceae | 8 |
| Taxus brevifolia | Nutt. | Taxaceae | 8 |
| Tellima grandiflora | (Pursh) Douglas ex Lindl. | Saxifragaceae | 8 |
| Tetradymia canescens | DC. | Asteraceae | 8 |
| Tetradymia glabrata | Torr. & A.Gray | Asteraceae | 8 |
| Tetradymia spinosa | Hook. & Arn. | Asteraceae | 8 |
| Tetrapteron graciliflorum | (Hook. & Arn.) W.L.Wagner & Hoch | Onagraceae | 8 |
| Teucrium canadense | L. | Lamiaceae | 8 |
| Thalictrum alpinum | L. | Ranunculaceae | 8 |
| Thalictrum fendleri | Engelm. ex A.Gray | Ranunculaceae | 8 |
| Thalictrum occidentale | A.Gray | Ranunculaceae | 8 |
| Thalictrum polycarpum | (Torr.) S.Watson | Ranunculaceae | 8 |
| Thalictrum sparsiflorum | Turcz. ex Fisch. & C.A.Mey. | Ranunculaceae | 8 |
| Thalictrum venulosum | Trel. | Ranunculaceae | 8 |
| Thelypodium integrifolium | (Nutt.) Endl. | Brassicaceae | 8 |
| Thelypodium laciniatum | (Hook.) Endl. | Brassicaceae | 8 |
| Thelypodium milleflorum | A.Nelson | Brassicaceae | 8 |
| Thermopsis gracilis | Howell | Fabaceae | 8 |
| Thermopsis montana | Nutt. | Fabaceae | 8 |
| Thuja plicata | Donn ex D.Don | Cupressaceae | 8 |
| Thysanocarpus curvipes | Hook. | Brassicaceae | 8 |
| Thysanocarpus radians | Benth. | Brassicaceae | 8 |
| Tiarella trifoliata | L. | Saxifragaceae | 8 |
| Tiquilia nuttallii | (Hook.) A.T.Richardson | Ehretiaceae | 8 |
| Tolmiea diplomenziesii | Judd, Soltis & P.S.Soltis | Saxifragaceae | 8 |
| Tolmiea menziesii | (Pursh) Torr. & A.Gray | Saxifragaceae | 8 |
| Tomostima platycarpa | (Torr. & A.Gray) Al-Shehbaz, M.Koch & Jordon-Thaden | Brassicaceae | 8 |
| Tomostima reptans | (Lam.) Al-Shehbaz, M.Koch & Jordon-Thaden | Brassicaceae | 8 |
| Tonella floribunda | A.Gray | Plantaginaceae | 8 |
| Tonella tenella | (Benth.) A.Heller | Plantaginaceae | 8 |
| Tonestus lyallii | A.Nelson | Asteraceae | 8 |
| Torreyostellaria jamesiana | (Torr.) Gang Yao, B.Xue & Z.Q.Song | Caryophyllaceae | 8 |
| Townsendia parryi | Eaton | Asteraceae | 8 |
| Townsendia scapigera | D.C.Eaton | Asteraceae | 8 |
| Toxicodendron diversilobum | (Torr. & A.Gray) Greene | Anacardiaceae | 8 |
| Toxicodendron radicans | (L.) Kuntze | Anacardiaceae | 8 |
| Toxicoscordion fremontii | (Torr.) Rydb. | Melanthiaceae | 8 |
| Toxicoscordion micranthum | (Eastw.) A.Heller | Melanthiaceae | 8 |
| Toxicoscordion paniculatum | (Nutt.) Rydb. | Melanthiaceae | 8 |
| Toxicoscordion venenosum | (S.Watson) Rydb. | Melanthiaceae | 8 |
| Trautvetteria caroliniensis | (Walter) Vail | Ranunculaceae | 8 |
| Triantha glutinosa | (Michx.) Baker | Tofieldiaceae | 8 |
| Triantha occidentalis | (S.Watson) R.R.Gates | Tofieldiaceae | 8 |
| Trichogalium boreale | (L.) Fourr. | Rubiaceae | 8 |
| Trichogalium oreganum | (Britton) Kadereit & Schneew. | Rubiaceae | 8 |
| Trichophorum cespitosum | (L.) Hartm. | Cyperaceae | 8 |
| Trichostema lanceolatum | Benth. | Lamiaceae | 8 |
| Trichostema oblongum | Benth. | Lamiaceae | 8 |
| Trichostema simulatum | Jeps. | Lamiaceae | 8 |
| Trifolium albopurpureum | Torr. & A.Gray | Fabaceae | 8 |
| Trifolium barbigerum | Torr. | Fabaceae | 8 |
| Trifolium beckwithii | W.H.Brewer ex S.Watson | Fabaceae | 8 |
| Trifolium bifidum | A.Gray | Fabaceae | 8 |
| Trifolium breweri | S.Watson | Fabaceae | 8 |
| Trifolium ciliolatum | Benth. | Fabaceae | 8 |
| Trifolium cyathiferum | Lindl. | Fabaceae | 8 |
| Trifolium depauperatum | Desv. | Fabaceae | 8 |
| Trifolium dichotomum | Hook. & Arn. | Fabaceae | 8 |
| Trifolium eriocephalum | Nutt. | Fabaceae | 8 |
| Trifolium fucatum | Lindl. | Fabaceae | 8 |
| Trifolium gracilentum | Torr. & A.Gray | Fabaceae | 8 |
| Trifolium gymnocarpon | Nutt. | Fabaceae | 8 |
| Trifolium longipes | Nutt. | Fabaceae | 8 |
| Trifolium macraei | Hook. & Arn. | Fabaceae | 8 |
| Trifolium macrocephalum | (Pursh) Poir. | Fabaceae | 8 |
| Trifolium microcephalum | Pursh | Fabaceae | 8 |
| Trifolium microdon | Hook. & Arn. | Fabaceae | 8 |
| Trifolium obtusiflorum | Hook. | Fabaceae | 8 |
| Trifolium oliganthum | Steud. | Fabaceae | 8 |
| Trifolium owyheense | Gilkey | Fabaceae | 8 |
| Trifolium productum | Greene | Fabaceae | 8 |
| Trifolium variegatum | Nutt. | Fabaceae | 8 |
| Trifolium willdenovii | Spreng. | Fabaceae | 8 |
| Trifolium wormskioldii | Lehm. | Fabaceae | 8 |
| Triglochin maritima | L. | Juncaginaceae | 8 |
| Triglochin palustris | L. | Juncaginaceae | 8 |
| Triglochin scilloides | (Poir.) Mering & Kadereit | Juncaginaceae | 8 |
| Triglochin striata | Ruiz & Pav. | Juncaginaceae | 8 |
| Trillium albidum | J.D.Freeman | Melanthiaceae | 8 |
| Trillium crassifolium | Piper | Melanthiaceae | 8 |
| Trillium kurabayashii | J.D.Freeman | Melanthiaceae | 8 |
| Trillium ovatum | Pursh | Melanthiaceae | 8 |
| Trillium petiolatum | Pursh | Melanthiaceae | 8 |
| Triodanis perfoliata | (L.) Nieuwl. | Campanulaceae | 8 |
| Triphysaria eriantha | (Benth.) T.I.Chuang & Heckard | Orobanchaceae | 8 |
| Triphysaria pusilla | (Benth.) T.I.Chuang & Heckard | Orobanchaceae | 8 |
| Triphysaria versicolor | Fisch. & C.A.Mey. | Orobanchaceae | 8 |
| Triplasis purpurea | (Walter) Chapm. | Poaceae | 8 |
| Triteleia bridgesii | (S.Watson) Greene | Asparagaceae | 8 |
| Triteleia crocea | (Alph.Wood) Greene | Asparagaceae | 8 |
| Triteleia grandiflora | Lindl. | Asparagaceae | 8 |
| Triteleia hendersonii | Greene | Asparagaceae | 8 |
| Tsuga heterophylla | (Raf.) Sarg. | Pinaceae | 8 |
| Tsuga mertensiana | (Bong.) Carrière | Pinaceae | 8 |
| Turritis glabra | L. | Brassicaceae | 8 |
| Typha angustifolia | L. | Typhaceae | 8 |
| Typha latifolia | L. | Typhaceae | 8 |
| Umbellularia californica | (Hook. & Arn.) Nutt. | Lauraceae | 8 |
| Uropappus lindleyi | (DC.) Nutt. | Asteraceae | 8 |
| Urtica gracilis | Aiton | Urticaceae | 8 |
| Utricularia gibba | L. | Lentibulariaceae | 8 |
| Utricularia intermedia | Hayne | Lentibulariaceae | 8 |
| Utricularia macrorhiza | Leconte | Lentibulariaceae | 8 |
| Utricularia minor | L. | Lentibulariaceae | 8 |
| Vaccinium cespitosum | Michx. | Ericaceae | 8 |
| Vaccinium deliciosum | Piper | Ericaceae | 8 |
| Vaccinium myrtillus | L. | Ericaceae | 8 |
| Vaccinium ovalifolium | Sm. | Ericaceae | 8 |
| Vaccinium ovatum | Pursh | Ericaceae | 8 |
| Vaccinium oxycoccos | L. | Ericaceae | 8 |
| Vaccinium parvifolium | Sm. | Ericaceae | 8 |
| Vaccinium scoparium | Leiberg ex Coville | Ericaceae | 8 |
| Vaccinium uliginosum | L. | Ericaceae | 8 |
| Vahlodea atropurpurea | (Wahlenb.) Fr. | Poaceae | 8 |
| Valeriana acutiloba | Rydb. | Caprifoliaceae | 8 |
| Valeriana californica | A.Heller | Caprifoliaceae | 8 |
| Valeriana ciliosa | (Greene) Byng & Christenh. | Caprifoliaceae | 8 |
| Valeriana congesta | (Lindl.) Byng & Christenh. | Caprifoliaceae | 8 |
| Valeriana edulis | Nutt. | Caprifoliaceae | 8 |
| Valeriana occidentalis | A.Heller | Caprifoliaceae | 8 |
| Valeriana sitchensis | Bong. | Caprifoliaceae | 8 |
| Vallisneria americana | Michx. | Hydrocharitaceae | 8 |
| Vancouveria chrysantha | Greene | Berberidaceae | 8 |
| Vancouveria hexandra | C.Morren & Decne. | Berberidaceae | 8 |
| Vancouveria planipetala | Calloni | Berberidaceae | 8 |
| Veratrum californicum | Durand | Melanthiaceae | 8 |
| Veratrum insolitum | Jeps. | Melanthiaceae | 8 |
| Veratrum viride | Aiton | Melanthiaceae | 8 |
| Verbena bracteata | Cav. ex Lag. & Rodr. | Verbenaceae | 8 |
| Verbena hastata | L. | Verbenaceae | 8 |
| Verbena lasiostachys | Link | Verbenaceae | 8 |
| Veronica americana | (Raf.) Schwein. ex Benth. | Plantaginaceae | 8 |
| Veronica californica | M.M.Mart.Ort. & Albach | Plantaginaceae | 8 |
| Veronica catenata | Pennell | Plantaginaceae | 8 |
| Veronica cusickii | A.Gray | Plantaginaceae | 8 |
| Veronica missurica | Raf. | Plantaginaceae | 8 |
| Veronica peregrina | L. | Plantaginaceae | 8 |
| Veronica regina-nivalis | M.M.Mart.Ort. & Albach | Plantaginaceae | 8 |
| Veronica rubra | (Douglas ex Hook.) M.M.Mart.Ort. & Albach | Plantaginaceae | 8 |
| Veronica scutellata | L. | Plantaginaceae | 8 |
| Veronica serpyllifolia | L. | Plantaginaceae | 8 |
| Veronica wormskjoldii | Roem. & Schult. | Plantaginaceae | 8 |
| Vesper purpurascens | (A.Gray) R.L.Hartm. & G.L.Nesom | Apiaceae | 8 |
| Viburnum edule | (Michx.) Raf. | Viburnaceae | 8 |
| Viburnum ellipticum | Hook. | Viburnaceae | 8 |
| Vicia americana | Muhl. ex Willd. | Fabaceae | 8 |
| Vicia hassei | S.Watson | Fabaceae | 8 |
| Vicia nigricans | Hook. & Arn. | Fabaceae | 8 |
| Viola adunca | Sm. | Violaceae | 8 |
| Viola bakeri | Greene | Violaceae | 8 |
| Viola canadensis | L. | Violaceae | 8 |
| Viola cuneata | S.Watson | Violaceae | 8 |
| Viola douglasii | Steud. | Violaceae | 8 |
| Viola glabella | Nutt. | Violaceae | 8 |
| Viola hallii | A.Gray | Violaceae | 8 |
| Viola howellii | A.Gray | Violaceae | 8 |
| Viola langsdorffii | Fisch. ex Ging. | Violaceae | 8 |
| Viola lobata | Benth. | Violaceae | 8 |
| Viola macloskeyi | F.E.Lloyd | Violaceae | 8 |
| Viola nephrophylla | Greene | Violaceae | 8 |
| Viola ocellata | Torr. & A.Gray | Violaceae | 8 |
| Viola orbiculata | (A.Gray) Geyer ex B.D.Jacks. | Violaceae | 8 |
| Viola palustris | L. | Violaceae | 8 |
| Viola praemorsa | Douglas | Violaceae | 8 |
| Viola primulifolia | L. | Violaceae | 8 |
| Viola purpurea | Kellogg | Violaceae | 8 |
| Viola sempervirens | Greene | Violaceae | 8 |
| Viola sheltonii | Torr. | Violaceae | 8 |
| Viola trinervata | (Howell) Howell ex A.Gray | Violaceae | 8 |
| Vitis californica | Benth. | Vitaceae | 8 |
| Vitis riparia | Michx. | Vitaceae | 8 |
| Whipplea modesta | Torr. | Hydrangeaceae | 8 |
| Wolffia borealis | (Engelm.) Landolt | Araceae | 8 |
| Wolffia columbiana | H.Karst. | Araceae | 8 |
| Woodsia oregana | D.C.Eaton | Woodsiaceae | 8 |
| Woodsia scopulina | D.C.Eaton | Woodsiaceae | 8 |
| Woodwardia fimbriata | Sm. | Blechnaceae | 8 |
| Wyethia amplexicaulis | (Nutt.) Nutt. | Asteraceae | 8 |
| Wyethia angustifolia | Nutt. | Asteraceae | 8 |
| Wyethia mollis | A.Gray | Asteraceae | 8 |
| Xanthium orientale | L. | Asteraceae | 8 |
| Xanthium spinosum | L. | Asteraceae | 8 |
| Xerophyllum tenax | (Pursh) Nutt. | Melanthiaceae | 8 |
| Yabea microcarpa | Koso-Pol. | Apiaceae | 8 |
| Zannichellia palustris | L. | Potamogetonaceae | 8 |
| Zeltnera exaltata | (Griseb.) G.Mans. | Gentianaceae | 8 |
| Zizania palustris | L. | Poaceae | 8 |
| Zizia aptera | (A.Gray) Fernald | Apiaceae | 8 |
| Zostera marina | L. | Zosteraceae | 8 |
| Actaea laciniata | (S.Watson) J.Compton | Ranunculaceae | 7 |
| Agoseris monticola | Greene | Asteraceae | 7 |
| Allium sanbornii | Alph.Wood | Amaryllidaceae | 7 |
| Antennaria flagellaris | A.Gray | Asteraceae | 7 |
| Astragalus accidens | S.Watson | Fabaceae | 7 |
| Astragalus cusickii | A.Gray | Fabaceae | 7 |
| Balsamorhiza rosea | A.Nelson & J.F.Macbr. | Asteraceae | 7 |
| Bromus marginatus | Nees ex Steud. | Poaceae | 7 |
| Carex integra | Mack. | Cyperaceae | 7 |
| Carex simulata | Mack. | Cyperaceae | 7 |
| Carex vernacula | L.H.Bailey | Cyperaceae | 7 |
| Castilleja chlorotica | Piper | Orobanchaceae | 7 |
| Castilleja peckiana | Pennell | Orobanchaceae | 7 |
| Chlorogalum angustifolium | Kellogg | Asparagaceae | 7 |
| Corispermum americanum | (Nutt.) Nutt. | Chenopodiaceae | 7 |
| Crepis modocensis | Greene | Asteraceae | 7 |
| Crepis runcinata | (E.James) Torr. & A.Gray | Asteraceae | 7 |
| Enemion stipitatum | J.R.Drumm. & Hutch. | Ranunculaceae | 7 |
| Epilobium rigidum | Hausskn. | Onagraceae | 7 |
| Eriastrum sparsiflorum | (Eastw.) H.Mason | Polemoniaceae | 7 |
| Eriogonum diclinum | Reveal | Polygonaceae | 7 |
| Festuca saximontana | Rydb. | Poaceae | 7 |
| Hesperocyparis bakeri | (Jeps.) Bartel | Cupressaceae | 7 |
| Juncus bolanderi | Engelm. | Juncaceae | 7 |
| Juncus orthophyllus | Coville | Juncaceae | 7 |
| Juncus oxymeris | Engelm. | Juncaceae | 7 |
| Lomatium gormanii | (Howell) J.M.Coult. & Rose | Apiaceae | 7 |
| Lupinus lapidicola | A.Heller | Fabaceae | 7 |
| Matricaria occidentalis | Greene | Asteraceae | 7 |
| Nemacladus rigidus | Curran | Campanulaceae | 7 |
| Penstemon rattanii | A.Gray | Plantaginaceae | 7 |
| Penstemon subserratus | Pennell | Plantaginaceae | 7 |
| Perideridia oregana | (Nutt.) Mathias | Apiaceae | 7 |
| Phacelia tetramera | J.T.Howell | Hydrophyllaceae | 7 |
| Plagiobothrys mollis | (A.Gray) I.M.Johnst. | Boraginaceae | 7 |
| Plantago eriopoda | Torr. | Plantaginaceae | 7 |
| Primula cusickiana | (A.Gray) A.Gray | Primulaceae | 7 |
| Primula poetica | (L.F.Hend.) A.R.Mast & Reveal | Primulaceae | 7 |
| Ribes marshallii | Greene | Grossulariaceae | 7 |
| Sabulina macra | (A.Nelson & J.F.Macbr.) Dillenb. & Kadereit | Caryophyllaceae | 7 |
| Scirpus pallidus | (Britton) Fernald | Cyperaceae | 7 |
| Silene serpentinicola | T.W.Nelson & J.P.Nelson | Caryophyllaceae | 7 |
| Sisyrinchium hitchcockii | Douglass M.Hend. | Iridaceae | 7 |
| Smelowskia ovalis | M.E.Jones | Brassicaceae | 7 |
| Streptanthus major | Jeps. | Brassicaceae | 7 |
| Suaeda occidentalis | (S.Watson) S.Watson | Chenopodiaceae | 7 |
| Townsendia montana | M.E.Jones | Asteraceae | 7 |
| Trifolium howellii | S.Watson | Fabaceae | 7 |
| Zeltnera muehlenbergii | (Griseb.) G.Mans. | Gentianaceae | 7 |
| Astragalus geyeri | A.Gray | Fabaceae | 6 |
| Astragalus misellus | S.Watson | Fabaceae | 6 |
| Astragalus mulfordiae | M.E.Jones | Fabaceae | 6 |
| Boechera rollei | (Rollins) Al-Shehbaz | Brassicaceae | 6 |
| Camassia cusickii | S.Watson | Asparagaceae | 6 |
| Carex cordillerana | Saarela & B.A.Ford | Cyperaceae | 6 |
| Carex halliana | L.H.Bailey | Cyperaceae | 6 |
| Collomia mazama | Coville | Polemoniaceae | 6 |
| Collomia tenella | A.Gray | Polemoniaceae | 6 |
| Dimeresia howellii | A.Gray | Asteraceae | 6 |
| Diplacus cascadensis | G.L.Nesom | Phrymaceae | 6 |
| Drymocallis campanulata | (C.L.Hitchc.) Ertter | Rosaceae | 6 |
| Eriogonum novonudum | M.Peck | Polygonaceae | 6 |
| Gayophytum diffusum | Torr. & A.Gray | Onagraceae | 6 |
| Isoetes occidentalis | L.F.Hend. | Isoetaceae | 6 |
| Kalmiopsis leachiana | (L.F.Hend.) Rehder | Ericaceae | 6 |
| Lathrocasis tenerrima | (A.Gray) L.A.Johnson | Polemoniaceae | 6 |
| Lupinus wyethii | S.Watson | Fabaceae | 6 |
| Luzula hitchcockii | Hämet-Ahti | Juncaceae | 6 |
| Melica spectabilis | Scribn. | Poaceae | 6 |
| Navarretia heterandra | H.Mason | Polemoniaceae | 6 |
| Navarretia sinistra | (M.E.Jones) L.A.Johnson | Polemoniaceae | 6 |
| Ozomelis diversifolia | (Greene) Rydb. | Saxifragaceae | 6 |
| Phacelia leonis | J.T.Howell | Hydrophyllaceae | 6 |
| Phalaris angusta | Nees ex Trin. | Poaceae | 6 |
| Phlox colubrina | Wherry & Constance | Polemoniaceae | 6 |
| Polygonum ramosissimum | Michx. | Polygonaceae | 6 |
| Potentilla sericata | (S.Watson) Greene | Rosaceae | 6 |
| Sabulina howellii | (S.Watson) Dillenb. & Kadereit | Caryophyllaceae | 6 |
| Saxifragopsis fragarioides | Small | Saxifragaceae | 6 |
| Scolochloa festucacea | (Willd.) Link | Poaceae | 6 |
| Allium tolmiei | Baker | Amaryllidaceae | 5 |
| Amsinckiopsis kingii | (S.Watson) Guilliams, Hasenstab & B.G.Baldwin | Boraginaceae | 5 |
| Arceuthobium tsugense | (Rosend.) G.N.Jones | Santalaceae | 5 |
| Astragalus tetrapterus | A.Gray | Fabaceae | 5 |
| Astragalus toanus | M.E.Jones | Fabaceae | 5 |
| Atriplex truncata | (Torr. ex S.Watson) A.Gray | Chenopodiaceae | 5 |
| Boechera microphylla | (Nutt.) Dorn | Brassicaceae | 5 |
| Bromus orcuttianus | Vasey | Poaceae | 5 |
| Carex jonesii | L.H.Bailey | Cyperaceae | 5 |
| Carex oederi | Retz. | Cyperaceae | 5 |
| Carex podocarpa | R.Br. | Cyperaceae | 5 |
| Carex praeceptorum | Mack. | Cyperaceae | 5 |
| Castilleja gracillima | Rydb. | Orobanchaceae | 5 |
| Cerastium viride | A.Heller | Caryophyllaceae | 5 |
| Drymocallis lactea | (Greene) Rydb. | Rosaceae | 5 |
| Drymocallis pseudorupestris | (Rydb.) Rydb. | Rosaceae | 5 |
| Eriocoma lemmonii | (Vasey) Romasch. | Poaceae | 5 |
| Gayophytum racemosum | Torr. & A.Gray | Onagraceae | 5 |
| Gilia modocensis | Eastw. | Polemoniaceae | 5 |
| Hackelia diffusa | I.M.Johnst. | Boraginaceae | 5 |
| Iris innominata | L.F.Hend. | Iridaceae | 5 |
| Iris tenuis | S.Watson | Iridaceae | 5 |
| Lomatium serpentinum | (M.E.Jones) Mathias | Apiaceae | 5 |
| Micranthes hitchcockiana | (Elvander) Brouillet & Gornall | Saxifragaceae | 5 |
| Micromonolepis pusilla | (Torr. ex S.Watson) Ulbr. | Chenopodiaceae | 5 |
| Muhlenbergia andina | (Nutt.) Hitchc. | Poaceae | 5 |
| Navarretia linearifolia | (Howell) L.A.Johnson | Polemoniaceae | 5 |
| Nothocalais alpestris | (A.Gray) K.L.Chambers | Asteraceae | 5 |
| Oreocarya nubigena | Greene | Boraginaceae | 5 |
| Orobanche parishii | (Jeps.) Heckard | Orobanchaceae | 5 |
| Phacelia argentea | A.Nelson & J.F.Macbr. | Hydrophyllaceae | 5 |
| Phacelia mutabilis | Greene | Hydrophyllaceae | 5 |
| Phalaris californica | Hook. & Arn. | Poaceae | 5 |
| Phoradendron libocedri | (Engelm.) Howell | Santalaceae | 5 |
| Polygonum polygaloides | Meisn. | Polygonaceae | 5 |
| Potentilla howellii | Greene | Rosaceae | 5 |
| Pyrola crypta | Jolles | Ericaceae | 5 |
| Ribes binominatum | A.Heller | Grossulariaceae | 5 |
| Rudbeckia alpicola | Piper | Asteraceae | 5 |
| Salix lemmonii | Bebb | Salicaceae | 5 |
| Trichogalium muricatum | (W.Wight) Kadereit & Schneew. | Rubiaceae | 5 |
| Acmispon denticulatus | (Drew) D.D.Sokoloff | Fabaceae | 4 |
| Arceuthobium cyanocarpum | (A.Nelson ex Rydb.) J.M.Coult. & A.Nelson | Santalaceae | 4 |
| Astragalus nudisiliquus | A.Nelson | Fabaceae | 4 |
| Astragalus tweedyi | Canby | Fabaceae | 4 |
| Boechera cusickii | (S.Watson) Al-Shehbaz | Brassicaceae | 4 |
| Bromus maritimus | (Piper) Hitchc. | Poaceae | 4 |
| Calochortus persistens | Ownbey | Liliaceae | 4 |
| Calycadenia fremontii | A.Gray | Asteraceae | 4 |
| Carex abrupta | Mack. | Cyperaceae | 4 |
| Carex pelocarpa | F.J.Herm. | Cyperaceae | 4 |
| Chrysothamnus humilis | Greene | Asteraceae | 4 |
| Delphinium depauperatum | Nutt. | Ranunculaceae | 4 |
| Diplacus deschutesensis | G.L.Nesom | Phrymaceae | 4 |
| Draba incerta | Payson | Brassicaceae | 4 |
| Ericameria resinosa | Nutt. | Asteraceae | 4 |
| Erigeron grandiflorus | Hook. | Asteraceae | 4 |
| Eriogonum crosbyae | Reveal | Polygonaceae | 4 |
| Eriogonum pendulum | S.Watson | Polygonaceae | 4 |
| Erythronium elegans | P.C.Hammond & K.L.Chambers | Liliaceae | 4 |
| Filipendula occidentalis | (S.Watson) Howell | Rosaceae | 4 |
| Gilia salticola | Eastw. | Polemoniaceae | 4 |
| Hackelia bella | I.M.Johnst. | Boraginaceae | 4 |
| Heuchera grossulariifolia | Rydb. | Saxifragaceae | 4 |
| Juncus bryoides | F.J.Herm. | Juncaceae | 4 |
| Juncus covillei | Piper | Juncaceae | 4 |
| Juncus laccatus | P.F.Zika | Juncaceae | 4 |
| Lepidium dictyotum | A.Gray | Brassicaceae | 4 |
| Leptosiphon harknessii | (Curran) J.M.Porter & L.A.Johnson | Polemoniaceae | 4 |
| Lilium occidentale | Purdy | Liliaceae | 4 |
| Lomatium greenmanii | Mathias | Apiaceae | 4 |
| Lupinus andersonii | S.Watson | Fabaceae | 4 |
| Mertensia brachycalyx | Piper | Boraginaceae | 4 |
| Mertensia nevadensis | A.Nelson | Boraginaceae | 4 |
| Micranthes gormanii | (Suksd.) Brouillet & Gornall | Saxifragaceae | 4 |
| Montia diffusa | (Nutt.) Greene | Montiaceae | 4 |
| Nemacladus capillaris | Greene | Campanulaceae | 4 |
| Oreocarya thompsonii | (I.M.Johnst.) Abrams | Boraginaceae | 4 |
| Packera bolanderi | (A.Gray) W.A.Weber & Á.Löve | Asteraceae | 4 |
| Packera flettii | (Wiegand) W.A.Weber & Á.Löve | Asteraceae | 4 |
| Penstemon globosus | (Piper) Pennell & D.D.Keck | Plantaginaceae | 4 |
| Penstemon miser | A.Gray | Plantaginaceae | 4 |
| Penstemon payettensis | A.Nelson & J.F.Macbr. | Plantaginaceae | 4 |
| Phlox caespitosa | Nutt. | Polemoniaceae | 4 |
| Plagiobothrys leptocladus | (Greene) I.M.Johnst. | Boraginaceae | 4 |
| Podagrostis humilis | (Vasey) Björkman | Poaceae | 4 |
| Potentilla cryptocaulis | Clokey | Rosaceae | 4 |
| Pyrrocoma racemosa | Torr. & A.Gray | Asteraceae | 4 |
| Rumex lacustris | Greene | Polygonaceae | 4 |
| Salix delnortensis | C.K.Schneid. | Salicaceae | 4 |
| Silene grayi | S.Watson | Caryophyllaceae | 4 |
| Silene suksdorfii | B.L.Rob. | Caryophyllaceae | 4 |
| Stellaria calycantha | (Ledeb.) Bong. | Caryophyllaceae | 4 |
| Agrostis variabilis | Rydb. | Poaceae | 3 |
| Astragalus hoodianus | Howell | Fabaceae | 3 |
| Boechera suffrutescens | (S.Watson) Dorn | Brassicaceae | 3 |
| Botrychium rubellum | Farrar & Stensvold | Ophioglossaceae | 3 |
| Calamagrostis bolanderi | Thurb. | Poaceae | 3 |
| Cardamine pattersonii | L.F.Hend. | Brassicaceae | 3 |
| Carex scopulorum | Holm | Cyperaceae | 3 |
| Chenopodium desiccatum | A.Nelson | Chenopodiaceae | 3 |
| Cirsium inamoenum | (Greene) D.J.Keil | Asteraceae | 3 |
| Crepis pleurocarpa | A.Gray | Asteraceae | 3 |
| Cryptantha torreyana | (A.Gray) Greene | Boraginaceae | 3 |
| Downingia laeta | (Greene) Greene | Campanulaceae | 3 |
| Draba crassifolia | Graham | Brassicaceae | 3 |
| Eriogonum ternatum | Howell | Polygonaceae | 3 |
| Erysimum inconspicuum | (S.Watson) MacMill. | Brassicaceae | 3 |
| Erythranthe latidens | (A.Gray) G.L.Nesom | Phrymaceae | 3 |
| Erythranthe scouleri | (Hook.) G.L.Nesom | Phrymaceae | 3 |
| Festuca minutiflora | Rydb. | Poaceae | 3 |
| Gentianella amarella | (L.) Börner | Gentianaceae | 3 |
| Lathyrus rigidus | T.G.White | Fabaceae | 3 |
| Lomatium peckianum | Mathias & Constance | Apiaceae | 3 |
| Lupinus onustus | S.Watson | Fabaceae | 3 |
| Marsilea oligospora | Goodd. | Marsileaceae | 3 |
| Oxypolis occidentalis | J.M.Coult. & Rose | Apiaceae | 3 |
| Packera subnuda | (DC.) Trock & T.M.Barkley | Asteraceae | 3 |
| Penstemon ovatus | Douglas | Plantaginaceae | 3 |
| Penstemon pennellianus | D.D.Keck | Plantaginaceae | 3 |
| Phlox viscida | E.E.Nelson | Polemoniaceae | 3 |
| Potentilla jepsonii | Ertter | Rosaceae | 3 |
| Potentilla shockleyi | (S.Watson) Jeps. | Rosaceae | 3 |
| Pyrrocoma lanceolata | (Hook.) Greene | Asteraceae | 3 |
| Pyrrocoma uniflora | (Hook.) Greene | Asteraceae | 3 |
| Ribes watsonianum | Koehne | Grossulariaceae | 3 |
| Romanzoffia thompsonii | Marttala | Hydrophyllaceae | 3 |
| Salix prolixa | Andersson | Salicaceae | 3 |
| Sedum leibergii | Britton | Crassulaceae | 3 |
| Stephanomeria paniculata | Nutt. | Asteraceae | 3 |
| Streptopus streptopoides | (Ledeb.) Frye & Rigg | Liliaceae | 3 |
| Thelypodium brachycarpum | Torr. | Brassicaceae | 3 |
| Thelypodium flexuosum | B.L.Rob. | Brassicaceae | 3 |
| Trichogalium bolanderi | (A.Gray) Kadereit & Schneew. | Rubiaceae | 3 |