| Scientific Name | Common Name(s) | Life History | Growth Form | |
|---|---|---|---|---|
|
Pennisetum ciliare | bufflegrass, buffle grass | Perennial | grass |
|
Pennisetum villosum | feathertop, feather grass, long-style feather grass, long styled feather grass, longstyle feather grass, long-styled feather grass, purple squirreltail grass, white foxtail, feathertop fountain grass | Perennial | grass |
|
Pennisetum x advena 'Rubrum' | 'Rubrum', purple fountain grass, foreign fountaingrass, red fountaingrass, 'Cupreum', rose fountain grass | Perennial | grass |
|
Pentaglottis sempervirens | evergreen bugloss, green alkanet, evergeen alkanet | ||
| Pentaschistis airoides | False hairgrass, Annual pentaschistis | Annual | grass | |
| Perovskia atriplicifolia | Russian Sage | Perennial | shrub | |
|
Persicaria wallichii | Himalayan knotweed, Cultivated knotweed | Perennial | forb |
| Petasites japonicus (Siebold & Zucc.) Maxim. | Japanese sweet coltsfoot, butterbur | Perennial | forb | |
|
Phalaris arundinacea 'Picta' | Picta, reed canary grass, gardener's-garters, ribbon grass, variegated grass, reed canarygrass, canarygrass | ||
| Phellodendron amurense | Amur corktree | Perennial | tree | |
|
Phoenix canariensis | Canary Island date palm, Canary date palm, palmera Canaria (Spanish), date palm, phoenix palm, Canary Island palm, Pineapple palm, Palmera canaria | Perennial | tree |
| Phoenix dactylifera | date palm, date | Perennial | tree | |
|
Photinia serratifolia | Taiwanese photinia, Chinese photinia | Perennial | tree |
|
Photinia x fraseri | Fraser's photinia | Perennial | tree |
|
Phyllostachys aurea | golden bamboo, fish-pole bamboo | Perennial | grass |
| Phyllostachys bambusoides | Bamboo, Castillon | |||
| Physalis subglabrata | Longleaf smooth ground cherry, Husk tomato, Smooth groundcherry | Perennial | forb | |
|
Phytolacca americana | American pokeweed, pigeonberry, pokeroot, inkberry coakum | Perennial | forb |
| Phytolacca heterotepala | Mexican pokeweed | |||
|
Picea abies (L.) H.Karst. | Norway spruce | Perennial | tree |
|
Pinus sylvestris | Scots Pine | Perennial | tree |
|
Pistacia chinensis | Chinese pistachio | Perennial | tree |
| Pistacia chinensis 'Keith Davey' | Keith Davey Chinese pistache, Chinese pistachio 'Keith Davey', Chinese pistache, Chinese pistachio, green almond, mastic tree, pistachio nut tree | Perennial | tree | |
|
Pittosporum tobira | Japanese cheesewood, Japanese pittosporum, Mock orange, Australian-laurel | Perennial | tree |
|
Pittosporum undulatum | Victorian box, Australian cheesewood , engraver-wood , mock orange, wave-leaf pittosporum, white-holly | Perennial | shrub |