| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| PEPAF | Petasites palmatus (Ait.) Gray var. frigidus Macoun | Petasites frigidus var. nivalis | Asteraceae
|
| PEPA31 | Petasites palmatus (Ait.) Gray | Petasites frigidus var. palmatus | Asteraceae
|
| PESA5 | Petasites sagittatus (Banks ex Pursh) Gray | arrowleaf sweet coltsfoot | Asteraceae
|
| PESP7 | Petasites speciosus (Nutt.) Piper | Petasites frigidus var. palmatus | Asteraceae
|
| PETR9 | Petasites trigonophylla Greene | Petasites vitifolius | Asteraceae
|
| PEVI14 | Petasites �vitifolius Greene (pro sp.) | | Asteraceae
|
| PEVU3 | Petasites vulgaris Hill | Petasites hybridus | Asteraceae
|
| PEWA15 | Petasites warrenii St. John | Petasites frigidus var. nivalis | Asteraceae
|
| PETAS | Petasites P. Mill. | butterbur | Asteraceae
|
| PENE7 | Peteria nevadensis Tidestrom | Peteria thompsoniae | Fabaceae
|
| PESC3 | Peteria scoparia Gray | rush peteria | Fabaceae
|
| PETH5 | Peteria thompsoniae S. Wats. | Thompson's peteria | Fabaceae
|
| PETER | Peteria Gray | peteria | Fabaceae
|
| PEPE22 | Petesioides pendula (Urban) Britt. | Wallenia lamarckiana | Myrsinaceae
|
| PEYU | Petesioides yunquensis (Urban) Britt. | Wallenia yunquensis | Myrsinaceae
|
| PEDO | Petitia domingensis Jacq. | bastard stopper | Verbenaceae
|
| PETIT | Petitia Jacq. | petitia | Verbenaceae
|
| PEAL7 | Petiveria alliacea L. | guinea henweed | Phytolaccaceae
|
| PETIV | Petiveria L. | petiveria | Phytolaccaceae
|
| PEFA4 | Petractis farlowii (Tuck. ex Nyl.) Vezda | | Stictidaceae
|
| PETRA3 | Petractis Fr. | petractis | Stictidaceae
|
| PEDI3 | Petradoria discoidea L.C. Anders. | Chrysothamnus gramineus | Asteraceae
|
| PEPUG | Petradoria pumila (Nutt.) Greene ssp. graminea (Woot. & Standl.) L.C. Anders. | giant rockgoldenrod | Asteraceae
|
| PEPUP | Petradoria pumila (Nutt.) Greene ssp. pumila | grassy rockgoldenrod | Asteraceae
|
| PEPUG2 | Petradoria pumila (Nutt.) Greene var. graminea (Woot. & Standl.) Welsh | Petradoria pumila ssp. graminea | Asteraceae
|
| PEPU7 | Petradoria pumila (Nutt.) Greene | grassy rockgoldenrod | Asteraceae
|
| PETRA | Petradoria Greene | rockgoldenrod | Asteraceae
|
| PEKO3 | Petrea kohautiana K. Presl | Petrea volubilis | Verbenaceae
|
| PEVO | Petrea volubilis L. | queen's-wreath | Verbenaceae
|
| PETRE | Petrea L. | petrea | Verbenaceae
|
| PERE3 | Petrogenia repens I.M. Johnston | Bonamia repens | Convolvulaceae
|
| PEAC4 | Petrophyton acuminatum Rydb. | big arroyo rockmat | Rosaceae
|
| PECAA | Petrophyton caespitosum (Nutt.) Rydb. ssp. acuminatum (Rydb.) Munz | Petrophyton acuminatum | Rosaceae
|
| PECAC2 | Petrophyton caespitosum (Nutt.) Rydb. var. caespitosum | mat rockspirea | Rosaceae
|
| PECAE | Petrophyton caespitosum (Nutt.) Rydb. var. elatius (S. Wats.) Tidestrom | mat rockspirea | Rosaceae
|
| PECA12 | Petrophyton caespitosum (Nutt.) Rydb. | mat rockspirea | Rosaceae
|
| PECI4 | Petrophyton cinerascens (Piper) Rydb. | halfshrub rockmat | Rosaceae
|
| PEHE4 | Petrophyton hendersonii (Canby) Rydb. | Olympic Mountain rockmat | Rosaceae
|
| PETRO2 | Petrophyton Rydb. | rockspirea | Rosaceae
|
| PEDU2 | Petrorhagia dubia (Raf.) G. L�pez & Romo | hairypink | Caryophyllaceae
|
| PENA2 | Petrorhagia nanteuilii (Burnat) P.W. Ball & Heywood | proliferous pink | Caryophyllaceae
|
| PEPR4 | Petrorhagia prolifera (L.) P.W. Ball & Heywood | childing pink | Caryophyllaceae
|
| PESA9 | Petrorhagia saxifraga (L.) Link | saxifrage pink | Caryophyllaceae
|
| PEVE3 | Petrorhagia velutina (Guss.) P.W. Ball & Heywood | Petrorhagia dubia | Caryophyllaceae
|
| PETRO | Petrorhagia (Ser.) Link | pink | Caryophyllaceae
|
| PERE8 | Petrosedum reflexum (L.) Grulich | Sedum reflexum | Crassulaceae
|
| PECR2 | Petroselinum crispum (P. Mill.) Nyman ex A.W. Hill | parsley | Apiaceae
|
| PEHO6 | Petroselinum hortense Hoffm. | Petroselinum crispum | Apiaceae
|
| PESA17 | Petroselinum sativum Hoffm. | Petroselinum crispum | Apiaceae
|
| PEVU4 | Petroselinum vulgare Lagasca | Petroselinum crispum | Apiaceae
|
| PETRO6 | Petroselinum J. Hill | parsley | Apiaceae
|
| PEAT7 | Petunia �atkinsiana D. Don ex Loud. | | Solanaceae
|
| PEAX | Petunia axillaris (Lam.) B.S.P. | large white petunia | Solanaceae
|
| PEHY10 | Petunia �hybrida Vilm. | Petunia atkinsiana | Solanaceae
|
| PEIN5 | Petunia integrifolia (Hook.) Schinz & Thellung | violetflower petunia | Solanaceae
|
| PEPA14 | Petunia parviflora Juss. | Calibrachoa parviflora | Solanaceae
|
| PEVI18 | Petunia violacea Lindl. | Petunia integrifolia | Solanaceae
|
| PEVI6 | Petunia violacea auct. non Juss. | Petunia axillaris | Solanaceae
|
| PETUN | Petunia Juss. | petunia | Solanaceae
|
| PEAM7 | Peucedanum ambiguum (Nutt.) Nutt. ex Torr. & Gray | Lomatium ambiguum | Apiaceae
|
| PECA28 | Peucedanum canbyi Coult. & Rose | Lomatium canbyi | Apiaceae
|
| PEFA2 | Peucedanum farinosum Hook. | Lomatium farinosum var. farinosum | Apiaceae
|
| PEGRA | Peucedanum graveolens S. Wats. var. alpinum S. Wats. | Lomatium graveolens var. alpinum | Apiaceae
|
| PEGR16 | Peucedanum graveolens S. Wats. | Lomatium graveolens var. graveolens | Apiaceae
|
| PEKA6 | Peucedanum kauaiense Hbd. | Peucedanum sandwicense | Apiaceae
|
| PEKIA | Peucedanum kingii S. Wats. var. alpinum (S. Wats.) Coult. & Rose | Lomatium graveolens var. alpinum | Apiaceae
|
| PEKI5 | Peucedanum kingii S. Wats. | Lomatium graveolens var. graveolens | Apiaceae
|
| PEMA14 | Peucedanum macrocarpum Nutt. ex Torr. & Gray | Lomatium macrocarpum | Apiaceae
|
| PEME9 | Peucedanum megarrhizum A. Nels. | Lomatium nuttallii | Apiaceae
|
| PEOS2 | Peucedanum ostruthium (L.) W.D.J. Koch | masterwort | Apiaceae
|
| PEPA22 | Peucedanum palustre (L.) Moench | hogfennel | Apiaceae
|
| PESA13 | Peucedanum sandbergii Coult. & Rose | Lomatium sandbergii | Apiaceae
|
| PESAH | Peucedanum sandwicense Hbd. var. hiroe O.& I. Deg. | Peucedanum sandwicense | Apiaceae
|
| PESA6 | Peucedanum sandwicense Hbd. | makou | Apiaceae
|
| PEUCE | Peucedanum L. | peucedanum | Apiaceae
|
| PESC4 | Peucephyllum schottii Gray | Schott's pygmycedar | Asteraceae
|
| PEUCE2 | Peucephyllum Gray | pygmycedar | Asteraceae
|
| PEBO5 | Peumus boldus Molina | boldo | Monimiaceae
|
| PEUMU | Peumus Molina | peumus | Monimiaceae
|
| PFGR | Pfaffia grandiflora (Hook.) R.E. Fries | jojo | Amaranthaceae
|
| PFAFF | Pfaffia Mart. | pfaffia | Amaranthaceae
|
| PHAM10 | Phaca americana (Hook.) Rydb. ex Small | Astragalus americanus | Fabaceae
|
| PHBO5 | Phaca bodinii (Sheldon) Rydb. ex Small | Astragalus bodinii | Fabaceae
|
| PHIN14 | Phaca intonsa (Sheldon) Rydb. ex Small | Astragalus villosus | Fabaceae
|
| PHLO7 | Phaca longifolia (Pursh) Nutt. | Astragalus ceramicus var. filifolius | Fabaceae
|
| PHNE8 | Phaca neglecta Torr. & Gray | Astragalus neglectus | Fabaceae
|
| PHOB2 | Phaca obcordata (Ell.) Rydb. ex Small | Astragalus obcordatus | Fabaceae
|
| PHSA7 | Phaca salsula Pallas | Sphaerophysa salsula | Fabaceae
|
| PHAD | Phacelia adenophora J.T. Howell | glandular yellow phacelia | Hydrophyllaceae
|
| PHAFP | Phacelia affinis Gray var. patens J.T. Howell | Phacelia affinis | Hydrophyllaceae
|
| PHAF | Phacelia affinis Gray | limestone phacelia | Hydrophyllaceae
|
| PHAL9 | Phacelia alba Rydb. | white phacelia | Hydrophyllaceae
|
| PHAL11 | Phacelia alpina Rydb. | Phacelia hastata var. hastata | Hydrophyllaceae
|
| PHAM | Phacelia amabilis Constance | Saline Valley phacelia | Hydrophyllaceae
|
| PHAMM | Phacelia ambigua M.E. Jones var. minutiflora (J. Voss) Atwood | Phacelia crenulata var. minutiflora | Hydrophyllaceae
|
| PHAM8 | Phacelia ambigua M.E. Jones | Phacelia crenulata var. ambigua | Hydrophyllaceae
|
| PHAN | Phacelia anelsonii J.F. Macbr. | Aven Nelson's phacelia | Hydrophyllaceae
|
| PHAR | Phacelia argentea A. Nels. & J.F. Macbr. | sanddune phacelia | Hydrophyllaceae
|
| PHAR2 | Phacelia argillacea Atwood | Attwood's phacelia | Hydrophyllaceae
|
| PHAR13 | Phacelia arizonica Gray | Arizona phacelia | Hydrophyllaceae
|
| PHAU | Phacelia austromontana J.T. Howell | Southern Sierra phacelia | Hydrophyllaceae
|