| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| PSSA | Pseudophoenix sargentii H. Wendl. ex Sarg. | Florida cherry palm | Arecaceae
|
| PSVI3 | Pseudophoenix vinifera auct. non (Mart.) Becc. | Pseudophoenix sargentii ssp. sargentii | Arecaceae
|
| PSEUD5 | Pseudophoenix H. Wendl. ex Sarg. | pseudophoenix | Arecaceae
|
| PSPU3 | Pseudopyrenula pupula (Ach.) Mull. Arg. | Trypethelium floridanum | Trypetheliaceae
|
| PSSU4 | Pseudopyrenula subgregaria Mull. Arg. | Pseudopyrenula subnuda | Trypetheliaceae
|
| PSSU6 | Pseudopyrenula subnuda Mull. Arg. | | Trypetheliaceae
|
| PSEUD37 | Pseudopyrenula Mull. Arg. | pseudopyrenula | Trypetheliaceae
|
| PSAR6 | Pseudoroegneria arizonica (Scribn. & Merr.) A. L�ve | Elymus arizonicus | Poaceae
|
| PSSPI | Pseudoroegneria spicata (Pursh) A. L�ve ssp. inermis (Scribn. & J.G. Sm.) A. L�ve | beardless wheatgrass | Poaceae
|
| PSSPS | Pseudoroegneria spicata (Pursh) A. L�ve ssp. spicata | bluebunch wheatgrass | Poaceae
|
| PSSP6 | Pseudoroegneria spicata (Pursh) A. L�ve | bluebunch wheatgrass | Poaceae
|
| PSEUD22 | Pseudoroegneria (Nevski) A. L�ve | wheatgrass | Poaceae
|
| PSCY2 | Pseudorontium cyathiferum (Benth.) Rothm. | dog's-mouth | Scrophulariaceae
|
| PSEUD24 | Pseudorontium (Gray) Rothm. | pseudorontium | Scrophulariaceae
|
| PSAE | Pseudosagedia aenea (Wallr.) Hefellner & Kalb | Trichothelium aeneum | Trichotheliaceae
|
| PSCH2 | Pseudosagedia chlorotica (Ach.) Hafellner & Kalb | Trichothelium chloroticum | Trichotheliaceae
|
| PSGU4 | Pseudosagedia guentheri (Flotow) Hafellner & Kalb | Trichothelium guentheri | Trichotheliaceae
|
| PSLI5 | Pseudosagedia linearis (Leighton) Hafellner & Kalb | Trichothelium lineare | Trichotheliaceae
|
| PSNI5 | Pseudosagedia nitidula Mull. Arg. | Trichothelium nitidulum | Trichotheliaceae
|
| PSTH2 | Pseudosagedia thaxteri (R. Sant.) Hafellner & Kalb | Trichothelium thaxteri | Trichotheliaceae
|
| PSPI2 | Pseudosaponaria pilosa (Huds.) S. Ikonnikov | Gypsophila pilosa | Caryophyllaceae
|
| PSJA | Pseudosasa japonica (Sieb. & Zucc. ex Steud.) Makino ex Nakai | arrow bamboo | Poaceae
|
| PSEUD9 | Pseudosasa Makino ex Nakai | arrow bamboo | Poaceae
|
| PSPU4 | Pseudoscleropodium purum (Hedw.) Fleisch. in Broth. | pseudoscleropodium moss | Brachytheciaceae
|
| PSEUD32 | Pseudoscleropodium (Limpr.) Fleisch. in Broth. | pseudoscleropodium moss | Brachytheciaceae
|
| PSJA2 | Pseudostellaria jamesiana (Torr.) W.A. Weber & R.L. Hartman | tuber starwort | Caryophyllaceae
|
| PSEUD20 | Pseudostellaria Pax | pseudostellaria | Caryophyllaceae
|
| PSMO2 | Pseudotaenidia montana Mackenzie | Taenidia montana | Apiaceae
|
| PSDI2 | Pseudotaxiphyllum distichaceum (Mitt.) Iwats. | pseudotaxiphyllum moss | Hypnaceae
|
| PSEL3 | Pseudotaxiphyllum elegans (Brid.) Iwats. | elegant pseudotaxiphyllum moss | Hypnaceae
|
| PSHO4 | Pseudotaxiphyllum homomallifolium (Redf.) Irel. | pseudotaxiphyllum moss | Hypnaceae
|
| PSEUD41 | Pseudotaxiphyllum Iwats. | pseudotaxiphyllum moss | Hypnaceae
|
| PSFL3 | Pseudotsuga flahaultii Flous | Pseudotsuga menziesii var. glauca | Pinaceae
|
| PSMA | Pseudotsuga macrocarpa (Vasey) Mayr | bigcone Douglas-fir | Pinaceae
|
| PSMEF | Pseudotsuga menziesii (Mirbel) Franco var. flahaultii (Flous) Silba | Pseudotsuga menziesii var. glauca | Pinaceae
|
| PSMEG | Pseudotsuga menziesii (Mirbel) Franco var. glauca (Beissn.) Franco | Rocky Mountain Douglas-fir | Pinaceae
|
| PSMEM | Pseudotsuga menziesii (Mirbel) Franco var. menziesii | Douglas-fir | Pinaceae
|
| PSME | Pseudotsuga menziesii (Mirbel) Franco | Douglas-fir | Pinaceae
|
| PSMU2 | Pseudotsuga mucronata (Raf.) Sudw. | Pseudotsuga menziesii | Pinaceae
|
| PSTAG2 | Pseudotsuga taxifolia (Lamb.) Britt. var. glauca (Beissn.) Sudworth | Pseudotsuga menziesii var. glauca | Pinaceae
|
| PSTA2 | Pseudotsuga taxifolia (Lamb.) Britt. | Pseudotsuga menziesii var. menziesii | Pinaceae
|
| PSEUD7 | Pseudotsuga Carr. | Douglas-fir | Pinaceae
|
| PSAM | Psidium amplexicaule Pers. | mountain guava | Myrtaceae
|
| PSAR7 | Psidium araca Raddi | Psidium guineense | Myrtaceae
|
| PSCA5 | Psidium calyptranthoides Alain | Luquillo Mountain guava | Myrtaceae
|
| PSCAL | Psidium cattleianum Sabine var. littorale (Raddi) Mattos | Psidium cattleianum | Myrtaceae
|
| PSCA | Psidium cattleianum Sabine | strawberry guava | Myrtaceae
|
| PSFR3 | Psidium friedrichsthalianum (O. Berg) Niedenzu | wild guava | Myrtaceae
|
| PSGU | Psidium guajava L. | guava | Myrtaceae
|
| PSGU3 | Psidium guineense Sw. | Guinea guava | Myrtaceae
|
| PSIN3 | Psidium insulanum Alain | Psidium longipes var. orbiculare | Myrtaceae
|
| PSLIL | Psidium littorale Raddi var. longipes (Berg) Fosberg | Psidium longipes var. longipes | Myrtaceae
|
| PSLI3 | Psidium littorale Raddi | Psidium cattleianum | Myrtaceae
|
| PSLOL | Psidium longipes (Berg) McVaugh var. longipes | mangroveberry | Myrtaceae
|
| PSLOO | Psidium longipes (Berg) McVaugh var. orbiculare (Berg) McVaugh | Vieques Esland guava | Myrtaceae
|
| PSLO2 | Psidium longipes (Berg) McVaugh | mangroveberry | Myrtaceae
|
| PSMO8 | Psidium montanum Sw. | mountain guava | Myrtaceae
|
| PSSI2 | Psidium sintenisii (Kiaersk.) Alain | Sintenis' guava | Myrtaceae
|
| PSIDI | Psidium L. | guava | Myrtaceae
|
| PSOT | Psiguria ottoniana (Schlecht.) C. Jeffrey | Otton's pygmymelon | Cucurbitaceae
|
| PSPE2 | Psiguria pedata (L.) Howard | Caribbean pygmymelon | Cucurbitaceae
|
| PSTR2 | Psiguria trifoliata (L.) Alain | Psiguria pedata | Cucurbitaceae
|
| PSTR3 | Psiguria trilobata (L.) Howard | threelobe pygmymelon | Cucurbitaceae
|
| PSIGU | Psiguria Neck. ex Arn. | pygmymelon | Cucurbitaceae
|
| PSAS2 | Psilactis asteroides Gray | New Mexico tansyaster | Asteraceae
|
| PSBR5 | Psilactis brevilingulata Schultz-Bip. ex Hemsl. | Trans-Pecos tansyaster | Asteraceae
|
| PSCO7 | Psilactis coulteri auct. p.p. non Gray | Machaeranthera arida | Asteraceae
|
| PSGE | Psilactis gentryi (Standl.) D. Morgan | Mexican tansyaster | Asteraceae
|
| PSHE5 | Psilactis heterocarpa (R.L. Hartman & M.A. Lane) D. Morgan | San Patricio tansyaster | Asteraceae
|
| PSLE5 | Psilactis leptos Shinners | Psilactis asteroides | Asteraceae
|
| PSTE6 | Psilactis tenuis S. Wats. | slender tansyaster | Asteraceae
|
| PSILA2 | Psilactis Gray | tansyaster | Asteraceae
|
| PSBRB | Psilocarphus brevissimus Nutt. var. brevissimus | short woollyheads | Asteraceae
|
| PSBRM | Psilocarphus brevissimus Nutt. var. multiflorus Cronq. | dwarf woollyheads | Asteraceae
|
| PSBR | Psilocarphus brevissimus Nutt. | short woollyheads | Asteraceae
|
| PSEL | Psilocarphus elatior (Gray) Gray | meadow woollyheads | Asteraceae
|
| PSOR | Psilocarphus oregonus Nutt. | Oregon woollyheads | Asteraceae
|
| PSTEG | Psilocarphus tenellus Nutt. var. globiferus (Bertero ex DC.) Morefield | slender woollyheads | Asteraceae
|
| PSTET2 | Psilocarphus tenellus Nutt. var. tenellus | slender woollyheads | Asteraceae
|
| PSTET | Psilocarphus tenellus Nutt. var. tenuis (Eastw.) Cronq. | Psilocarphus tenellus var. globiferus | Asteraceae
|
| PSTE | Psilocarphus tenellus Nutt. | slender woollyheads | Asteraceae
|
| PSILO | Psilocarphus Nutt. | woollyheads | Asteraceae
|
| PSCO8 | Psilocarya corymbifera (C. Wright) Britt. | Rhynchospora scirpoides | Cyperaceae
|
| PSCO4 | Psilocarya corymbiformis Benth. | Rhynchospora scirpoides | Cyperaceae
|
| PSNI | Psilocarya nitens (Vahl) Wood | Rhynchospora nitens | Cyperaceae
|
| PSPO3 | Psilocarya portoricensis Britt. | Rhynchospora nitens | Cyperaceae
|
| PSRU | Psilocarya rufa Nees | Rhynchospora rufa | Cyperaceae
|
| PSSC4 | Psilocarya schiedeana (Nees) Liebm. | Rhynchospora eximia | Cyperaceae
|
| PSSCG | Psilocarya scirpoides Torr. var. grimesii Fern. & Grisc. | Rhynchospora scirpoides | Cyperaceae
|
| PSSC2 | Psilocarya scirpoides Torr. | Rhynchospora scirpoides | Cyperaceae
|
| PSACP | Psilochenia acuminata (Nutt.) W.A. Weber ssp. pluriflora (Babcock & Stebbins) W.A. Weber | Crepis acuminata ssp. pluriflora | Asteraceae
|
| PSAC | Psilochenia acuminata (Nutt.) W.A. Weber | Crepis acuminata ssp. acuminata | Asteraceae
|
| PSAT | Psilochenia atribarba (Heller) W.A. Weber | Crepis atribarba ssp. atribarba | Asteraceae
|
| PSBAC | Psilochenia bakeri (Greene) W.A. Weber ssp. cusickii (Eastw.) W.A. Weber | Crepis bakeri ssp. cusickii | Asteraceae
|
| PSBAI | Psilochenia bakeri (Greene) W.A. Weber ssp. idahoensis (Babcock & Stebbins) W.A. Weber | Crepis bakeri ssp. idahoensis | Asteraceae
|
| PSBA3 | Psilochenia bakeri (Greene) W.A. Weber | Crepis bakeri ssp. bakeri | Asteraceae
|
| PSIN4 | Psilochenia intermedia (Gray) W.A. Weber | Crepis intermedia | Asteraceae
|
| PSMOG | Psilochenia modocensis (Greene) W.A. Weber ssp. glareosa (Piper) W.A. Weber | Crepis modocensis ssp. glareosa | Asteraceae
|
| PSMOR | Psilochenia modocensis (Greene) W.A. Weber ssp. rostrata (Coville) W.A. Weber | Crepis modocensis ssp. rostrata | Asteraceae
|
| PSMOS | Psilochenia modocensis (Greene) W.A. Weber ssp. subacaulis (Kellogg) W.A. Weber | Crepis modocensis ssp. subacaulis | Asteraceae
|
| PSMO4 | Psilochenia modocensis (Greene) W.A. Weber | Crepis modocensis ssp. modocensis | Asteraceae
|