| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| PIJA | Piper jacquemontianum Kunth | Caracas pepper | Piperaceae
|
| PILE4 | Piper leptostachyon Nutt. | Peperomia humilis | Piperaceae
|
| PILO3 | Piper longifolium Ruiz & Pavon | pepper | Piperaceae
|
| PILO4 | Piper longum L. | Indian long pepper | Piperaceae
|
| PIMA8 | Piper maculosum L. | Peperomia maculosa | Piperaceae
|
| PIMA4 | Piper marginatum Jacq. | marigold pepper | Piperaceae
|
| PIME | Piper methysticum G. Forst. | kava | Piperaceae
|
| PINI3 | Piper nigrum L. | black pepper | Piperaceae
|
| PIOB4 | Piper obtusifolium L. | Peperomia obtusifolia | Piperaceae
|
| PIOF2 | Piper officinarum (Miq.) C. DC. | Piper retrofractum | Piperaceae
|
| PIOR | Piper ornatum N. E. Br. | Celebes pepper | Piperaceae
|
| PIPE6 | Piper pellucidum L. | Peperomia pellucida | Piperaceae
|
| PIPE4 | Piper peltatum L. | Lepianthes peltata | Piperaceae
|
| PIPO3 | Piper ponapense C. DC. | pepper | Piperaceae
|
| PIQU2 | Piper quadrifolium L. | Peperomia quadrifolia | Piperaceae
|
| PIRE9 | Piper retrofractum Vahl | Javanese long pepper | Piperaceae
|
| PIRO7 | Piper rotundifolium L. | Peperomia rotundifolia | Piperaceae
|
| PISC | Piper scabrum Sw., non Lam. | Piper hispidum | Piperaceae
|
| PISE5 | Piper serpens Sw. | Peperomia serpens | Piperaceae
|
| PISW | Piper swartzianum (Miq.) C. DC. | spanish elder | Piperaceae
|
| PITE8 | Piper tenellum Sw. | Peperomia tenella | Piperaceae
|
| PITE9 | Piper tetraphyllum G. Forst. | Peperomia tetraphylla | Piperaceae
|
| PITR7 | Piper treleaseanum Britt. & Wilson | Piper glabrescens | Piperaceae
|
| PITU | Piper tuberculatum auct. non Jacq. | Piper swartzianum | Piperaceae
|
| PIUM | Piper umbellatum L. | Lepianthes peltata | Piperaceae
|
| PIWY | Piper wydlerianum (Miq.) C. DC. | Piper jacquemontianum | Piperaceae
|
| PIPER | Piper L. | pepper | Piperaceae
|
| PICA13 | Piperia candida R. Morgan & Ackerman | whiteflower rein orchid | Orchidaceae
|
| PICO8 | Piperia colemanii R. Morgan & Glicenstein | Coleman's piperia | Orchidaceae
|
| PICO9 | Piperia cooperi (S. Wats.) Rydb. | Cooper's rein orchid | Orchidaceae
|
| PIELD2 | Piperia elegans (Lindl.) Rydb. ssp. decurtata R. Morgan & Glicenstein | elegant piperia | Orchidaceae
|
| PIELE4 | Piperia elegans (Lindl.) Rydb. ssp. elegans | elegant piperia | Orchidaceae
|
| PIELE | Piperia elegans (Lindl.) Rydb. var. elata (Jepson) Luer | Piperia elongata | Orchidaceae
|
| PIEL2 | Piperia elegans (Lindl.) Rydb. | elegant piperia | Orchidaceae
|
| PIELM | Piperia elongata Rydb. ssp. michaelii (Greene) Ackerman | Piperia michaelii | Orchidaceae
|
| PIEL4 | Piperia elongata Rydb. | denseflower rein orchid | Orchidaceae
|
| PILA3 | Piperia lancifolia Rydb. | Piperia elongata | Orchidaceae
|
| PILE3 | Piperia leptopetala Rydb. | Piperia elongata | Orchidaceae
|
| PILO2 | Piperia longispica Dur. | Piperia elongata | Orchidaceae
|
| PIMA3 | Piperia maritima (Greene) Rydb. | Piperia elegans ssp. elegans | Orchidaceae
|
| PIMI6 | Piperia michaelii (Greene) Rydb. | Michael's piperia | Orchidaceae
|
| PIMU5 | Piperia multiflora Rydb. | Piperia elegans ssp. elegans | Orchidaceae
|
| PITR3 | Piperia transversa Suksdorf | royal rein orchid | Orchidaceae
|
| PIUN3 | Piperia unalascensis (Spreng.) Rydb. | slender-spire orchid | Orchidaceae
|
| PIYA | Piperia yadonii R. Morgan & Ackerman | Yadon's piperia | Orchidaceae
|
| PIPER2 | Piperia Rydb. | rein orchid | Orchidaceae
|
| PIPE3 | Piptadenia peregrina (L.) Benth. | Anadenanthera peregrina | Fabaceae
|
| PIPE7 | Piptanthocereus peruvianus auct. non (L.) Riccob. | Cereus hildmannianus | Cactaceae
|
| PICA17 | Piptatherum canadense (Poir) Barkworth, comb. nov. ined. | Canadian ricegrass | Poaceae
|
| PICO6 | Piptatherum confine J.A. Schultes | Arundinella confinis | Poaceae
|
| PIEX3 | Piptatherum exiguum (Thurb.) Barkworth, comb. nov. ined. | little ricegrass | Poaceae
|
| PIMI7 | Piptatherum micranthum (Trin. & Rupr.) Barkworth | littleseed ricegrass | Poaceae
|
| PIMI3 | Piptatherum miliaceum (L.) Coss. | smilograss | Poaceae
|
| PIPU7 | Piptatherum pungens (Torr.) Barkworth, comb. nov. ined. | mountain ricegrass | Poaceae
|
| PIRA5 | Piptatherum racemosum Ricker ex A.S. Hitchc. | blackseed ricegrass | Poaceae
|
| PIPTA2 | Piptatherum Beauv. | ricegrass | Poaceae
|
| PITE6 | Piptocarpha tetrantha Urban | mountain ashdaisy | Asteraceae
|
| PIPTO2 | Piptocarpha R. Br. | ashdaisy | Asteraceae
|
| PIAV | Piptochaetium avenaceum (L.) Parodi | blackseed speargrass | Poaceae
|
| PIAV2 | Piptochaetium avenacioides (Nash) Valencia & Costas | Florida speargrass | Poaceae
|
| PIFIC | Piptochaetium fimbriatum (Kunth) A.S. Hitchc. var. confine I.M. Johnston | Piptochaetium fimbriatum | Poaceae
|
| PIFI | Piptochaetium fimbriatum (Kunth) A.S. Hitchc. | pinyon ricegrass | Poaceae
|
| PIPR2 | Piptochaetium pringlei (Beal) Parodi | Pringle's speargrass | Poaceae
|
| PISE4 | Piptochaetium setosum (Trin.) Arech. | bristly speargrass | Poaceae
|
| PIPTO | Piptochaetium J. Presl | speargrass | Poaceae
|
| PIAC6 | Piptocoma acevedoi Pruski | Acevedo's velvetshrub | Asteraceae
|
| PIAN4 | Piptocoma antillana Urban | Antilles velvetshrub | Asteraceae
|
| PIRU4 | Piptocoma rufescens auct. non Cass. | Piptocoma antillana | Asteraceae
|
| PIPTO3 | Piptocoma Cass. | velvetshrub | Asteraceae
|
| PIAL2 | Pipturus albidus (Hook. & Arn.) Gray | Waimea pipturus | Urticaceae
|
| PIBR2 | Pipturus brighamii Skottsberg | Pipturus albidus | Urticaceae
|
| PIFO2 | Pipturus forbesii Krajina | Forbes' pipturus | Urticaceae
|
| PIGAA | Pipturus gaudichaudianus Weddell var. asperrimus Skottsberg | Pipturus albidus | Urticaceae
|
| PIGAH | Pipturus gaudichaudianus Weddell var. hualalaiensis Skottsberg | Pipturus albidus | Urticaceae
|
| PIGA | Pipturus gaudichaudianus Weddell | Pipturus albidus | Urticaceae
|
| PIHAE | Pipturus hawaiensis Levl. var. eriocarpus (Skottsberg) Skottsberg | Pipturus albidus | Urticaceae
|
| PIHAI | Pipturus hawaiensis Levl. var. integrifolius O.& I. Deg. | Pipturus albidus | Urticaceae
|
| PIHAM | Pipturus hawaiensis Levl. var. molokaiensis (Skottsberg) O.& I. Deg. | Pipturus albidus | Urticaceae
|
| PIHA2 | Pipturus hawaiensis Levl. | Pipturus albidus | Urticaceae
|
| PIHE2 | Pipturus helleri Skottsberg | Pipturus albidus | Urticaceae
|
| PIKA | Pipturus kauaiensis Heller | Kauai pipturus | Urticaceae
|
| PIOA | Pipturus oahuensis Skottsberg | Pipturus albidus | Urticaceae
|
| PIPA8 | Pipturus pachyphyllus Skottsberg | Pipturus albidus | Urticaceae
|
| PIPT | Pipturus pterocarpus Skottsberg | Pipturus albidus | Urticaceae
|
| PIRO4 | Pipturus rockii Skottsberg | Pipturus albidus | Urticaceae
|
| PIRU2 | Pipturus ruber Heller | red pipturus | Urticaceae
|
| PISK | Pipturus skottsbergii Krajina | Pipturus albidus | Urticaceae
|
| PIPTU | Pipturus Weddell | pipturus | Urticaceae
|
| PICY | Pireella cymbifolia (Sull.) Card. | pireella moss | Pterobryaceae
|
| PILU3 | Pireella ludoviciae Grout | Pireella pohlii | Pterobryaceae
|
| PIPO2 | Pireella pohlii (Schwaegr.) Card. | Pohl's pireella moss | Pterobryaceae
|
| PIREE | Pireella Card. | pireella moss | Pterobryaceae
|
| PICAE | Piriqueta caroliniana (Walt.) Urban var. exasperata Urban | Piriqueta cistoides ssp. caroliniana | Turneraceae
|
| PICAG | Piriqueta caroliniana (Walt.) Urban var. glabra (DC.) Urban | Piriqueta cistoides ssp. caroliniana | Turneraceae
|
| PICAT | Piriqueta caroliniana (Walt.) Urban var. tomentosa (Wood) Urban | Piriqueta cistoides ssp. caroliniana | Turneraceae
|
| PICAV | Piriqueta caroliniana (Walt.) Urban var. viridis (Small) G.S. Torr. | Piriqueta cistoides ssp. caroliniana | Turneraceae
|
| PICA6 | Piriqueta caroliniana (Walt.) Urban | Piriqueta cistoides ssp. caroliniana | Turneraceae
|
| PICIC | Piriqueta cistoides (L.) Griseb. ssp. caroliniana (Walt.) Arbo | pitted stripeseed | Turneraceae
|
| PICIC2 | Piriqueta cistoides (L.) Griseb. ssp. cistoides | pitted stripeseed | Turneraceae
|
| PICI | Piriqueta cistoides (L.) Griseb. | pitted stripeseed | Turneraceae
|
| PIGL6 | Piriqueta glabrescens Small | Piriqueta cistoides ssp. caroliniana | Turneraceae
|