| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| PTPE | Pteryxia petraea (M.E. Jones) Coult. & Rose | rockloving wavewing | Apiaceae
|
| PTTEA | Pteryxia terebinthina (Hook.) Coult. & Rose var. albiflora (Torr. & Gray) Mathias | turpentine wavewing | Apiaceae
|
| PTTEC | Pteryxia terebinthina (Hook.) Coult. & Rose var. calcarea (M.E. Jones) Mathias | Pteryxia terebinthina var. albiflora | Apiaceae
|
| PTTEC2 | Pteryxia terebinthina (Hook.) Coult. & Rose var. californica (Coult. & Rose) Mathias | California wavewing | Apiaceae
|
| PTTEF | Pteryxia terebinthina (Hook.) Coult. & Rose var. foeniculacea (Nutt. ex Torr. & Gray) Mathias | turpentine wavewing | Apiaceae
|
| PTTET | Pteryxia terebinthina (Hook.) Coult. & Rose var. terebinthina | turpentine wavewing | Apiaceae
|
| PTTE | Pteryxia terebinthina (Hook.) Coult. & Rose | turpentine wavewing | Apiaceae
|
| PTERY | Pteryxia (Nutt. ex Torr. & Gray) Nutt. ex Coult. & Rose | wavewing | Apiaceae
|
| PTKI | Ptilagrostis kingii (Boland.) Barkworth | Sierra false needlegrass | Poaceae
|
| PTMOP | Ptilagrostis mongholica (Turcz. ex Trin.) Griseb. ssp. porteri (Rydb.) Barkworth | Ptilagrostis porteri | Poaceae
|
| PTMO3 | Ptilagrostis mongholica (Turcz. ex Trin.) Griseb. | Ptilagrostis porteri | Poaceae
|
| PTPO | Ptilagrostis porteri (Rydb.) W.A. Weber | Porter's false needlegrass | Poaceae
|
| PTILA | Ptilagrostis Griseb. | false needlegrass | Poaceae
|
| PTCA5 | Ptilidium californicum (Austin) Pearson | | Ptilidiaceae
|
| PTCI | Ptilidium ciliare (L.) Hampe | | Ptilidiaceae
|
| PTPU2 | Ptilidium pulcherrimum (Weber) Vainio | | Ptilidiaceae
|
| PTILI2 | Ptilidium Nees | | Ptilidiaceae
|
| PTCA | Ptilimnium capillaceum (Michx.) Raf. | herbwilliam | Apiaceae
|
| PTCO | Ptilimnium costatum (Ell.) Raf. | ribbed mock bishopweed | Apiaceae
|
| PTFLV | Ptilimnium fluviatile (Rose) Mathias var. viviparum (Rose) Reveal & Broome | Ptilimnium nodosum | Apiaceae
|
| PTFL | Ptilimnium fluviatile (Rose) Mathias | Ptilimnium nodosum | Apiaceae
|
| PTMA6 | Ptilimnium macrospermum Kartesz, sp. nov. ined. | | Apiaceae
|
| PTNO | Ptilimnium nodosum (Rose) Mathias | piedmont mock bishopweed | Apiaceae
|
| PTNU | Ptilimnium nuttallii (DC.) Britt. | laceflower | Apiaceae
|
| PTTE2 | Ptilimnium �texense Coult. & Rose (pro sp.) | | Apiaceae
|
| PTVI3 | Ptilimnium viviparum (Rose) Mathias | Ptilimnium nodosum | Apiaceae
|
| PTILI | Ptilimnium Raf. | mock bishopweed | Apiaceae
|
| PTCR70 | Ptilium crista-castrensis (Hedw.) De Not. | knights plume moss | Hypnaceae
|
| PTILI3 | Ptilium De Not. | ptilium moss | Hypnaceae
|
| PTNU2 | Ptilocalais nutans (Hook.) Greene | Microseris nutans | Asteraceae
|
| PTGR2 | Ptilocalyx greggii Torr. & Gray | Tiquilia greggii | Boraginaceae
|
| PTPA4 | Ptiloria pauciflora (Torr.) Raf. | Stephanomeria pauciflora | Asteraceae
|
| PTRA | Ptiloria ramosa Rydb. | Stephanomeria runcinata | Asteraceae
|
| PTXY | Ptychographa xylographoides Nyl. | | Agyriaceae
|
| PTYCH3 | Ptychographa Nyl. | ptychographa | Agyriaceae
|
| PTPO3 | Ptychomeria portoricensis (Urban) Schlechter | Gymnosiphon niveus | Burmanniaceae
|
| PTDR2 | Ptychomitrium drummondii (Wils.) Sull. | Drummond's ptychomitrium moss | Ptychomitriaceae
|
| PTGA | Ptychomitrium gardneri Lesq. | Gardner's ptychomitrium moss | Ptychomitriaceae
|
| PTIN4 | Ptychomitrium incurvum (Schwaegr.) Spruce | ptychomitrium moss | Ptychomitriaceae
|
| PTLE | Ptychomitrium leibergii Best | Leiberg's ptychomitrium moss | Ptychomitriaceae
|
| PTSE2 | Ptychomitrium serratum (C. M�ll.) Bruch & Schimp. in Besch. | serrate ptychomitrium moss | Ptychomitriaceae
|
| PTYCH2 | Ptychomitrium F�rnr. | ptychomitrium moss | Ptychomitriaceae
|
| PTEL | Ptychosperma elegans (R. Br.) Blume | | Arecaceae
|
| PTYCH4 | Ptychosperma Labill. | ptychosperma | Arecaceae
|
| PUAG | Puccinellia agrostidea Sorensen | bent alkaligrass | Poaceae
|
| PUAI | Puccinellia airoides (Nutt.) S. Wats. & Coult. | Puccinellia nuttalliana | Poaceae
|
| PUAL | Puccinellia alaskana Scribn. & Merr. | Puccinellia tenella ssp. alaskana | Poaceae
|
| PUAM2 | Puccinellia americana Sorensen | American alkaligrass | Poaceae
|
| PUAN | Puccinellia andersonii Swallen | Anderson's alkaligrass | Poaceae
|
| PUAN2 | Puccinellia angustata (R. Br.) Rand & Redf. | narrow alkaligrass | Poaceae
|
| PUAR | Puccinellia arctica (Hook.) Fern. & Weatherby | arctic alkaligrass | Poaceae
|
| PUBO | Puccinellia borealis Swallen | Puccinellia arctica | Poaceae
|
| PUBO2 | Puccinellia borreri (Bab.) Hayek | Puccinellia fasciculata | Poaceae
|
| PUCA | Puccinellia californica (Beetle) Munz | Torreyochloa californica | Poaceae
|
| PUCOP | Puccinellia coarctata Fern. & Weatherby var. pseudofasciculata Sorensen | Puccinellia distans ssp. borealis | Poaceae
|
| PUCO | Puccinellia coarctata Fern. & Weatherby | Puccinellia distans ssp. borealis | Poaceae
|
| PUCO2 | Puccinellia contracta (Lange) Sorensen | Puccinellia angustata | Poaceae
|
| PUCU | Puccinellia cusickii Weatherby | Puccinellia nuttalliana | Poaceae
|
| PUDIB | Puccinellia distans (Jacq.) Parl. ssp. borealis (Holmb.) W.E. Hughes | weeping alkaligrass | Poaceae
|
| PUDID | Puccinellia distans (Jacq.) Parl. ssp. distans | weeping alkaligrass | Poaceae
|
| PUDIH | Puccinellia distans (Jacq.) Parl. ssp. hauptiana (Trin. ex Krecz.) W.E. Hughes | Hauptian alkaligrass | Poaceae
|
| PUDIA | Puccinellia distans (Jacq.) Parl. var. angustifolia (Blytt) Holmb. | Puccinellia distans ssp. borealis | Poaceae
|
| PUDIM | Puccinellia distans (Jacq.) Parl. var. minor (S. Wats.) Boivin | Puccinellia tenella ssp. langeana | Poaceae
|
| PUDIT | Puccinellia distans (Jacq.) Parl. var. tenuis (Uechtr.) Fern. & Weatherby | Puccinellia distans ssp. distans | Poaceae
|
| PUDI | Puccinellia distans (Jacq.) Parl. | weeping alkaligrass | Poaceae
|
| PUER | Puccinellia erecta (A.S. Hitchc.) Munz | Torreyochloa erecta | Poaceae
|
| PUFA | Puccinellia fasciculata (Torr.) Bickn. | saltmarsh alkaligrass | Poaceae
|
| PUFE | Puccinellia fernaldii (A.S. Hitchc.) E.G. Voss | Torreyochloa pallida var. fernaldii | Poaceae
|
| PUGE | Puccinellia geniculata Krecz. | Puccinellia phryganodes ssp. geniculata | Poaceae
|
| PUGL | Puccinellia glabra Swallen | Puccinellia andersonii | Poaceae
|
| PUGR | Puccinellia grandis Swallen | Puccinellia nutkaensis | Poaceae
|
| PUHA | Puccinellia hauptiana (Trin. ex Krecz.) Kitagawa | Puccinellia distans ssp. hauptiana | Poaceae
|
| PUHO | Puccinellia howellii J.I. Davis | Howell's alkaligrass | Poaceae
|
| PUHU | Puccinellia hultenii Swallen | Hulten's alkaligrass | Poaceae
|
| PUIN | Puccinellia interior Sorensen | interior alkaligrass | Poaceae
|
| PUKAS | Puccinellia kamtschatica Holmb. var. sublaevis Holmb. | Puccinellia sublaevis | Poaceae
|
| PUKA | Puccinellia kamtschatica Holmb. | Alaska alkaligrass | Poaceae
|
| PUKU | Puccinellia kurilensis auct. non (Takeda) Honda p.p. | Puccinellia pumila | Poaceae
|
| PUKU | Puccinellia kurilensis auct. non (Takeda) Honda p.p. | Puccinellia tenella ssp. alaskana | Poaceae
|
| PULAA | Puccinellia langeana (Berlin) Sorensen ex Hult�n ssp. alaskana (Scribn. & Merr.) Sorensen | Puccinellia tenella ssp. alaskana | Poaceae
|
| PULAA2 | Puccinellia langeana (Berlin) Sorensen ex Hult�n ssp. asiatica Sorensen | Puccinellia tenella ssp. tenella | Poaceae
|
| PULA | Puccinellia langeana (Berlin) Sorensen ex Hult�n | Puccinellia tenella ssp. langeana | Poaceae
|
| PULE | Puccinellia lemmonii (Vasey) Scribn. | Lemmon's alkaligrass | Poaceae
|
| PULE2 | Puccinellia lettermanii (Vasey) Ponert | Poa lettermanii | Poaceae
|
| PULO2 | Puccinellia longiglumis Fern. & Weatherby | Puccinellia tenella ssp. langeana | Poaceae
|
| PULU2 | Puccinellia lucida Fern. & Weatherby | shining alkaligrass | Poaceae
|
| PUMA | Puccinellia maritima (Huds.) Parl. | seaside alkaligrass | Poaceae
|
| PUMA3 | Puccinellia maritima auct. non (Huds.) Parl. | Puccinellia americana | Poaceae
|
| PUNU | Puccinellia nutkaensis (J. Presl) Fern. & Weatherby | Nootka alkaligrass | Poaceae
|
| PUNU2 | Puccinellia nuttalliana (J.A. Schultes) A.S. Hitchc. | Nuttall's alkaligrass | Poaceae
|
| PUPA2 | Puccinellia pallida (Torr.) Clausen | Torreyochloa pallida var. pallida | Poaceae
|
| PUPA | Puccinellia parishii A.S. Hitchc. | bog alkaligrass | Poaceae
|
| PUPAH | Puccinellia pauciflora (J. Presl) Munz var. holmii (Beal) C.L. Hitchc. | Torreyochloa pallida var. pauciflora | Poaceae
|
| PUPAM2 | Puccinellia pauciflora (J. Presl) Munz var. microtheca (Buckl.) C.L. Hitchc. | Torreyochloa pallida var. pauciflora | Poaceae
|
| PUPA3 | Puccinellia pauciflora (J. Presl) Munz | Torreyochloa pallida var. pauciflora | Poaceae
|
| PUPAA | Puccinellia paupercula (Holm) Fern. & Weatherby var. alaskana (Scribn. & Merr.) Fern. & Weatherby | Puccinellia tenella ssp. alaskana | Poaceae
|
| PUPAL | Puccinellia paupercula (Holm) Fern. & Weatherby var. longiglumis Fern. & Weatherby | Puccinellia tenella ssp. langeana | Poaceae
|
| PUPA4 | Puccinellia paupercula (Holm) Fern. & Weatherby | Puccinellia tenella ssp. langeana | Poaceae
|
| PUPHG | Puccinellia phryganodes (Trin.) Scribn. & Merr. ssp. geniculata (Krecz.) Tzvelev | jointed alkaligrass | Poaceae
|
| PUPHP | Puccinellia phryganodes (Trin.) Scribn. & Merr. ssp. phryganodes | creeping alkaligrass | Poaceae
|
| PUPH | Puccinellia phryganodes (Trin.) Scribn. & Merr. | creeping alkaligrass | Poaceae
|