| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| PAMY | Paxistima myrsinites (Pursh) Raf. | Oregon boxleaf | Celastraceae
|
| PAXIS | Paxistima Raf. | paxistima | Celastraceae
|
| PEAR10 | Peccania arizonica (Tuck.) Herre | | Lichinaceae
|
| PEKA8 | Peccania kansana (Tuck.) Forss. | | Lichinaceae
|
| PESU9 | Peccania subnigra (de Lesd.) Wetmore | | Lichinaceae
|
| PETE17 | Peccania texana (Tuck.) Wetmore | | Lichinaceae
|
| PECCA | Peccania A. Massal. | peccania | Lichinaceae
|
| PECAA2 | Pecluma camptophyllaria (F�e) M.G. Price ssp. abbreviata (A.M. Evans) Kartesz & Gandhi | Colombian rockcap fern | Polypodiaceae
|
| PECAC | Pecluma camptophyllaria (F�e) M.G. Price ssp. camptophyllaria | Colombian rockcap fern | Polypodiaceae
|
| PECA26 | Pecluma camptophyllaria (F�e) M.G. Price | Colombian rockcap fern | Polypodiaceae
|
| PECO29 | Pecluma consimilis (Mett.) M.G. Price | montane rockcap fern | Polypodiaceae
|
| PEDI8 | Pecluma dispersa (A.M. Evans) M.G. Price | widespread rockcap fern | Polypodiaceae
|
| PEPE29 | Pecluma pectinata (L.) M.G. Price | combleaf rockcap fern | Polypodiaceae
|
| PEPL5 | Pecluma plumula (Humb. & Bonpl. ex Willd.) M.G. Price | plumed rockcap fern | Polypodiaceae
|
| PEPTC | Pecluma ptilodon (Kunze) M.G. Price ssp. caespitosum (Jenman) Windham | palmleaf rockcap fern | Polypodiaceae
|
| PEPTC2 | Pecluma ptilodon (Kunze) M.G. Price var. caespitosum (Jenman) Lellinger | Pecluma ptilodon ssp. caespitosum | Polypodiaceae
|
| PEPT2 | Pecluma ptilodon (Kunze) M.G. Price | palmleaf rockcap fern | Polypodiaceae
|
| PECLU | Pecluma M.G. Price | rockcap fern | Polypodiaceae
|
| PEBR20 | Pectiantia breweri (Gray) Rydb. | Mitella breweri | Saxifragaceae
|
| PEOV5 | Pectiantia ovalis (Greene) Rydb. | Mitella ovalis | Saxifragaceae
|
| PEPE16 | Pectiantia pentandra (Hook.) Rydb. | Mitella pentandra | Saxifragaceae
|
| PEANA | Pectis angustifolia Torr. var. angustifolia | narrowleaf pectis | Asteraceae
|
| PEANF | Pectis angustifolia Torr. var. fastigiata (Gray) Keil | lemonscent | Asteraceae
|
| PEANT | Pectis angustifolia Torr. var. tenella (DC.) Keil | lemonscent | Asteraceae
|
| PEAN | Pectis angustifolia Torr. | lemonscent | Asteraceae
|
| PECA18 | Pectis carthusianorum Less. | Caribbean cinchweed | Asteraceae
|
| PECI7 | Pectis ciliaris L. | donkeyweed | Asteraceae
|
| PECY | Pectis cylindrica (Fern.) Rydb. | Sonoran cinchweed | Asteraceae
|
| PEELF | Pectis elongata Kunth var. floribunda (A. Rich.) Keil | tropical cinchweed | Asteraceae
|
| PEEL6 | Pectis elongata Kunth | tropical cinchweed | Asteraceae
|
| PEFE3 | Pectis febrifuga van Hall | Pectis linearis | Asteraceae
|
| PEFIS | Pectis filipes Harvey & Gray var. subnuda Fern. | fivebract cinchweed | Asteraceae
|
| PEFI | Pectis filipes Harvey & Gray | fivebract cinchweed | Asteraceae
|
| PEFL12 | Pectis floribunda A. Rich. | Pectis elongata var. floribunda | Asteraceae
|
| PEFL14 | Pectis �floridana Keil | | Asteraceae
|
| PEGL16 | Pectis glaucescens (Cass.) Keil | sanddune cinchweed | Asteraceae
|
| PEHU4 | Pectis humifusa Sw. | yerba de San Juan | Asteraceae
|
| PEIM | Pectis imberbis Gray | beardless cinchweed | Asteraceae
|
| PELE10 | Pectis leptocephala (Cass.) Urban | Pectis glaucescens | Asteraceae
|
| PELI8 | Pectis linearifolia Urban | Florida cinchweed | Asteraceae
|
| PELI14 | Pectis linearis Llave | West Indian cinchweed | Asteraceae
|
| PELI9 | Pectis linifolia L. | romero macho | Asteraceae
|
| PELO | Pectis longipes Gray | longstalk cinchweed | Asteraceae
|
| PEMU10 | Pectis multisetosa Rydb. | Pectis prostrata | Asteraceae
|
| PEPA34 | Pectis palmeri S. Wats. | Pectis rusbyi | Asteraceae
|
| PEPAG | Pectis papposa Harvey & Gray var. grandis Keil | manybristle cinchweed | Asteraceae
|
| PEPAP3 | Pectis papposa Harvey & Gray var. papposa | manybristle cinchweed | Asteraceae
|
| PEPA2 | Pectis papposa Harvey & Gray | manybristle cinchweed | Asteraceae
|
| PEPO3 | Pectis portoricensis Urban | Pectis ciliaris | Asteraceae
|
| PEPOC | Pectis postrata Cav. var. cylindrica Fern. | Pectis cylindrica | Asteraceae
|
| PEPRU | Pectis prostrata Cav. var. urceolata Fern. | Pectis prostrata | Asteraceae
|
| PEPR | Pectis prostrata Cav. | spreading cinchweed | Asteraceae
|
| PERU6 | Pectis rusbyi Greene ex Gray | Rusby's cinchweed | Asteraceae
|
| PETE | Pectis tenella DC. | Pectis angustifolia var. tenella | Asteraceae
|
| PETE10 | Pectis tenuicaulis Urban | island cinchweed | Asteraceae
|
| PETE12 | Pectis texana Cory | Pectis angustifolia var. fastigiata | Asteraceae
|
| PECTI | Pectis L. | cinchweed | Asteraceae
|
| PEGRP | Pectocarya gracilis I.M. Johnston var. platycarpa Munz & Johnston | Pectocarya platycarpa | Boraginaceae
|
| PEHE | Pectocarya heterocarpa (I.M. Johnston) I.M. Johnston | chuckwalla combseed | Boraginaceae
|
| PELIF2 | Pectocarya linearis (Ruiz & Pav�n) DC. ssp. ferocula (I.M. Johnston) Thorne | sagebrush combseed | Boraginaceae
|
| PELIF | Pectocarya linearis (Ruiz & Pav�n) DC. var. ferocula I.M. Johnston | Pectocarya linearis ssp. ferocula | Boraginaceae
|
| PELIP2 | Pectocarya linearis (Ruiz & Pav�n) DC. var. penicillata (Hook. & Arn.) M.E. Jones | Pectocarya penicillata | Boraginaceae
|
| PELIP3 | Pectocarya linearis (Ruiz & Pav�n) DC. var. platycarpa (Munz & Johnston) Cronq. | Pectocarya platycarpa | Boraginaceae
|
| PELI | Pectocarya linearis (Ruiz & Pav�n) DC. | sagebrush combseed | Boraginaceae
|
| PEPEH | Pectocarya penicillata (Hook. & Arn.) A. DC. var. heterocarpa I.M. Johnston | Pectocarya heterocarpa | Boraginaceae
|
| PEPE26 | Pectocarya penicillata (Hook. & Arn.) A. DC. | sleeping combseed | Boraginaceae
|
| PEPE33 | Pectocarya peninsularis I.M. Johnston | peninsular pectocarya | Boraginaceae
|
| PEPL | Pectocarya platycarpa (Munz & Johnston) Munz & Johnston | broadfruit combseed | Boraginaceae
|
| PEPU | Pectocarya pusilla (A. DC.) Gray | little combseed | Boraginaceae
|
| PERE | Pectocarya recurvata I.M. Johnston | curvenut combseed | Boraginaceae
|
| PESE | Pectocarya setosa Gray | moth combseed | Boraginaceae
|
| PECTO | Pectocarya DC. ex Meisn. | combseed | Boraginaceae
|
| PEVE5 | Pediculariopsis verticillata (L.) A.& D. L�ve | Pedicularis verticillata | Scrophulariaceae
|
| PEAL12 | Pedicularis albolabiata (Hult�n) Kozh. | Pedicularis sudetica ssp. albolabiata | Scrophulariaceae
|
| PEAL17 | Pedicularis albomarginata M.E. Jones | Pedicularis crenulata | Scrophulariaceae
|
| PEAN11 | Pedicularis anaticeps Pennell | Pedicularis parryi ssp. purpurea | Scrophulariaceae
|
| PEAN9 | Pedicularis angustifolia Benth. | Mogollon Mountain lousewort | Scrophulariaceae
|
| PEAN12 | Pedicularis angustissima Greene | Pedicularis angustifolia | Scrophulariaceae
|
| PEAR8 | Pedicularis arctica R. Br. | Pedicularis langsdorfii ssp. arctica | Scrophulariaceae
|
| PEAT6 | Pedicularis atrosanguinea Pennell & J.W. Thompson | Pedicularis bracteosa var. atrosanguinea | Scrophulariaceae
|
| PEAT8 | Pedicularis attenuata Benth. | Pedicularis densiflora ssp. densiflora | Scrophulariaceae
|
| PEATA | Pedicularis attollens Gray ssp. attollens | little elephantshead | Scrophulariaceae
|
| PEATP3 | Pedicularis attollens Gray ssp. protogyna Pennell | little elephantshead | Scrophulariaceae
|
| PEAT | Pedicularis attollens Gray | little elephantshead | Scrophulariaceae
|
| PEAU4 | Pedicularis auriculata Sm. | Pedicularis lanceolata | Scrophulariaceae
|
| PEBRP3 | Pedicularis bracteosa Benth. ssp. paysoniana (Pennell) W.A. Weber | Pedicularis bracteosa var. paysoniana | Scrophulariaceae
|
| PEBRA | Pedicularis bracteosa Benth. var. atrosanguinea (Pennell & J.W. Thompson) Cronq. | bracted lousewort | Scrophulariaceae
|
| PEBRB | Pedicularis bracteosa Benth. var. bracteosa | bracted lousewort | Scrophulariaceae
|
| PEBRC | Pedicularis bracteosa Benth. var. canbyi (Gray) Cronq. | Canby's lousewort | Scrophulariaceae
|
| PEBRF | Pedicularis bracteosa Benth. var. flavida (Pennell) Cronq. | towering lousewort | Scrophulariaceae
|
| PEBRL | Pedicularis bracteosa Benth. var. latifolia (Pennell) Cronq. | widepetal lousewort | Scrophulariaceae
|
| PEBRP | Pedicularis bracteosa Benth. var. pachyrhiza (Pennell) Cronq. | towering lousewort | Scrophulariaceae
|
| PEBRP2 | Pedicularis bracteosa Benth. var. paysoniana (Pennell) Cronq. | Payson's lousewort | Scrophulariaceae
|
| PEBRS | Pedicularis bracteosa Benth. var. siifolia (Rydb.) Cronq. | smoothflower lousewort | Scrophulariaceae
|
| PEBR | Pedicularis bracteosa Benth. | bracted lousewort | Scrophulariaceae
|
| PEBR18 | Pedicularis brunnescens Heller | Pedicularis densiflora ssp. densiflora | Scrophulariaceae
|
| PECAC3 | Pedicularis canadensis L. ssp. canadensis | Canadian lousewort | Scrophulariaceae
|
| PECAF | Pedicularis canadensis L. ssp. fluviatilis (Heller) W.A. Weber | Canadian lousewort | Scrophulariaceae
|
| PECAD4 | Pedicularis canadensis L. var. dobbsii Fern. | Pedicularis canadensis ssp. canadensis | Scrophulariaceae
|
| PECA | Pedicularis canadensis L. | Canadian lousewort | Scrophulariaceae
|
| PECA32 | Pedicularis canbyi Gray | Pedicularis bracteosa var. canbyi | Scrophulariaceae
|