Canada's Plant Hardiness Site

Data have been entered for 7138 species.

(Last updated Wed Jan 14 11:46:39 EST 2015)
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Pachysandra procumbens Alleghany pachysandra
Pachysandra terminalis Japanese pachysandra
Packera aurea golden groundsel
Packera cana woolly groundsel
Packera cymbalaria dwarf arctic groundsel
Packera glabella grassleaf groundsel
Packera hesperia western ragwort
Packera indecora rayless mountain groundsel
Packera millefolium piedmont ragwort
Packera obovata roundleaf groundsel
Packera pauciflora alpine groundsel
Packera paupercula balsam groundsel
Packera plattensis prairie groundsel
Packera pseudaurea var. semicordata heartleaf groundsel
Packera schweinitziana Schweinitz's groundsel
Packera subnuda
Packera tridenticulata
Paeonia anomala Russian fernleaf peony
Paeonia delavayi maroon tree peony
Paeonia lactiflora common garden peony
Paeonia mlokosewitschii golden peony
Paeonia officinalis cottage peony
Paeonia suffruticosa Japanese tree peony
Paeonia tenuifolia fringed peony
Panax quinquefolius Canadian ginseng
Panax trifolius groundnut
Panicum capillare common witchgrass
Panicum dichotomiflorum fall panicgrass
Panicum dichotomiflorum subsp. puritanorum spreading panicgrass
Panicum flexile wiry witchgrass
Panicum miliaceum broomcorn millet
Panicum philadelphicum Philadelphia witchgrass
Panicum philadelphicum subsp. gattingeri Gattinger's witchgrass
Panicum philadelphicum subsp. philadelphicum Philadelphia witchgrass
Panicum rigidulum redtop panicgrass
Panicum rigidulum subsp. pubescens redtop panicgrass
Panicum rigidulum subsp. rigidulum redtop panicgrass
Panicum virgatum switch grass
Papaver alboroseum pale poppy
Papaver alpinum Hybrids hybrid alpine poppy
Papaver atlanticum Atlas poppy
Papaver dubium longpod poppy
Papaver gorodkovii arctic poppy
Papaver keelei Macoun's poppy
Papaver nudicaule Iceland poppy
Papaver orientale Oriental poppy
Papaver pygmaeum dwarf alpine poppy
Papaver rhoeas corn poppy
Papaver somniferum opium poppy
Papaver walpolei Walpole's poppy
Paradisea liliastrum St. Bruno's lily
Parietaria pensylvanica Pennsylvania pellitory
Paris quadrifolia herb paris
Parnassia fimbriata fringed grass-of-Parnassus
Parnassia glauca fen grass-of-Parnassus
Parnassia grandifolia largeleaf grass-of-Parnassus
Parnassia kotzebuei Kotzebue's grass-of-Parnassus
Parnassia palustris mountain grass-of-Parnassus
Parnassia parviflora smallflower grass-of-Parnassus
Paronychia ahartii
Paronychia argyrocoma
Paronychia canadensis smooth forked nailwort
Paronychia chartacea subsp. chartacea
Paronychia fastigiata hairy forked nailwort
Paronychia sessiliflora creeping nailwort
Parrotia persica Persian parrotia
Parrya nudicaulis
Parthenium alpinum
Parthenium integrifolium wild quinine
Parthenocissus inserta thicket creeper
Parthenocissus quinquefolia Boston ivy
Parthenocissus quinquefolia var. engelmannii Engelman's ivy
Parthenocissus tricuspidata Japanese creeper
Parthenocissus vitacea false Virginia creeper
Pascopyrum smithii bluestem wheatgrass
Paspalum setaceum beadgrass
Paspalum setaceum var. stramineum yellow sand paspalum
Passiflora caerulea blue crown passionflower
Passiflora incarnata purple passionflower
Pastinaca sativa wild parsnip
Paulownia tomentosa princess tree
Paxistima canbyi Canby's mountain-lover
Paxistima myrsinites Oregon box
Pectocarya penicillata sleeping combseed
Pedicularis bracteosa
Pedicularis canadensis wood betony
Pedicularis capitata
Pedicularis contorta
Pedicularis flammea redtipped lousewort
Pedicularis furbishiae
Pedicularis groenlandica elephantshead
Pedicularis hirsuta
Pedicularis labradorica Labrador woodbetony
Pedicularis lanata
Pedicularis lanceolata swamp woodbetony
Pedicularis lapponica Lapland woodbetony
Pedicularis macrodonta muskeg lousewort
Pedicularis oederi
Pedicularis palustris
Pedicularis parviflora sparseflowered lousewort
Pedicularis racemosa
Pedicularis sudetica Sudetic wood betony
Pedicularis sudetica subsp. interioides inland Sudetic wood betony
Pediocactus simpsonii Simpson's hedgehog cactus
Pediomelum argophyllum
Pediomelum esculentum prairie turnip
Pellaea atropurpurea purplestem cliffbrake
Pellaea gastonyi Gastony's cliffbrake
Pellaea glabella smooth cliffbrake
Pellaea glabella subsp. glabella smooth cliffbrake
Pellaea glabella subsp. simplex simple cliffbrake
Peltandra sagittifolia white arrow arum
Peltandra virginica green arrow arum
Pennisetum alopecuroides Chinese fountain grass
Penstemon albidus white beardtongue
Penstemon barbatus Hybrids beardtongue
Penstemon calycosus longsepal beardtongue
Penstemon canescens
Penstemon cobaea
Penstemon cobaea subsp. purpureus
Penstemon confertus yellow penstemon
Penstemon digitalis foxglove beardtongue
Penstemon ellipticus rocky ledge penstemon
Penstemon eriantherus fuzzytongue penstemon
Penstemon filiformis
Penstemon fruticosus bush penstemon
Penstemon fruticosus var. fruticosus shrubby penstemon
Penstemon fruticosus var. scouleri littleleaf bush penstemon
Penstemon gracilis slender beardtongue
Penstemon harringtonii
Penstemon haydenii
Penstemon hirsutus hairy beardtongue
Penstemon lemhiensis
Penstemon lyallii Lyall's penstemon
Penstemon nitidus waxleaf beardtongue
Penstemon oklahomensis
Penstemon pallidus pale beardtongue
Penstemon peckii
Penstemon pinifolius pineneedle beardtongue
Penstemon procerus smallflower beardtongue
Penstemon serrulatus coast beardtongue
Penstemon strictus stiff beardtongue
Penstemon tubiflorus tubular penstemon
Pentagramma triangularis subsp. triangularis goldenback fern
Penthorum sedoides Virginia stonecrop
Perideridia americana eastern yampah
Perideridia gairdneri false caraway
Perilla frutescens beefsteak plant
Peritoma serrulata Rocky Mountain beeplant
Perityle intricata desert rock daisy
Perovskia atriplicifolia Russian sage
Persea borbonia redbay
Persea palustris swamp red bay
Persicaria amphibia amphibious knotweed;
Persicaria arifolia arumleaf tearthumb
Persicaria careyi Carey's smartweed
Persicaria hydropiper marsh-pepper smartweed
Persicaria hydropiperoides swamp smartweed
Persicaria lapathifolia pale smartweed
Persicaria maculosa spotted lady's-thumb
Persicaria minor small waterpepper
Persicaria orientalis oriental smartweed
Persicaria pensylvanica pink knotweed
Persicaria polymorpha giant fleeceflower
Persicaria punctata dotted smartweed
Persicaria robustior stout smartweed
Persicaria sagittata arrow-vine
Persicaria virginiana jumpseed
Petalostemon candidum white prairie clover
Petalostemon purpureum purple prairie clover
Petasites frigidus arctic sweet coltsfoot
Petasites frigidus var. palmatus northern sweet coltsfoot
Petasites frigidus var. sagittatus arrowhead sweet coltsfoot
Petasites japonicus var. giganteus giant Japanese butterbur
Petrorhagia saxifraga tunic flower
Petunia Xhybrida garden petunia
Phacelia franklinii Franklin's phacelia
Phacelia hastata
Phacelia hastata var. hastata
Phacelia linearis
Phacelia minutissima
Phacelia mollis
Phacelia nashiana
Phacelia purshii
Phacelia sericea
Phacelia thermalis
Phacelia verna
Phalaris arundinacea reed canarygrass
Phalaris canariensis annual canarygrass
Phaseolus polystachios
Phedimus aizoon aizoön stonecrop
Phegopteris connectilis long beech fern
Phegopteris hexagonoptera broad beech fern
Phellodendron amurense Chinese corktree
Phellodendron japonicum
Philadelphus coronarius sweet mockorange
Philadelphus inodorus
Philadelphus lewisii Lewis' mockorange
Philadelphus pekinensis Peking mockorange
Philadelphus pubescens hoary mockorange
Philadelphus Xvirginalis virginal mockorange
Phippsia algida icegrass
Phippsia concinna snowgrass
Phlebodium aureum golden polypody
Phleum alpinum alpine timothy
Phleum pratense common timothy
Phlomis russelliana Jerusalem sage
Phlomis tuberosa sage-leaf mullein
Phlox adsurgens mountain phlox
Phlox alyssifolia blue phlox
Phlox bifida
Phlox bifida subsp. stellaria
Phlox caespitosa tufted phlox
Phlox carolina Carolina phlox
Phlox diffusa spreading phlox
Phlox divaricata wild blue phlox
Phlox douglasii moss phlox
Phlox drummondii annual phlox
Phlox glaberrima smooth phlox
Phlox gracilis slender phlox
Phlox gracilis subsp. gracilis slender phlox
Phlox gracilis subsp. humilis slender phlox
Phlox hoodii Hood's phlox
Phlox longifolia longleaf phlox
Phlox maculata meadow phlox
Phlox maculata subsp. maculata spotted phlox
Phlox paniculata summer phlox
Phlox pilosa prairie phlox
Phlox pilosa subsp. pilosa prairie phlox
Phlox pulchra mountain phlox
Phlox richardsonii subsp. richardsonii Richardson's phlox
Phlox stolonifera creeping phlox
Phlox subulata mountain phlox
Phlox subulata subsp. brittonii Britton's phlox
Pholisma sonorae
Phoradendron leucarpum
Phormium tenax New Zealand flax
Photinia davidiana prostrate stranvaesia
Photinia villosa Oriental photinia
Photinia Xfraseri fraser photinia
Phragmites australis common reed
Phragmites australis subsp. americanus American reed
Phryma leptostachya American lopseed
Phuopsis stylosa crosswort
Phyla lanceolata lance-leaved fogfruit
Phyllodoce caerulea blue mountainheath
Phyllodoce empetriformis pink mountainheath
Phyllodoce glanduliflora
Phyllospadix serrulatus serrulate surfgrass
Phyllostachys aurea golden bamboo
Phyllostachys aureosulcata yellow groove bamboo
Phyllostachys bambusoides giant timber bamboo
Phyllostachys nigra black bamboo
Physalis alkekengi Chinese lanterns
Physalis heterophylla wild ground cherry
Physalis longifolia longleaf ground cherry
Physalis longifolia var. subglabrata smooth groundcherry
Physaria arctica arctic bladderpod
Physaria arenosa sand bladderpod
Physaria arenosa subsp. arenosa sand bladderpod
Physaria calderi Calder’s bladderpod
Physaria didymocarpa double twinpod
Physaria didymocarpa var. didymocarpa double twinpod
Physaria douglasii Columbia bladderpod
Physaria douglasii subsp. douglasii Douglas's bladderpod
Physaria spatulata spatulateleaf bladderpod
Physocarpus capitatus Pacific ninebark
Physocarpus malvaceus mallow-leaf ninebark
Physocarpus monogynus mountain ninebark
Physocarpus opulifolius ninebark
Physostegia ledinghamii
Physostegia parviflora western false dragonhead
Physostegia virginiana obedient plant
Physostegia virginiana subsp. virginiana obedient plant
Phytolacca americana Virginia poke
Picea abies Norway spruce
Picea asperata Dragon spruce
Picea breweriana Brewer's spruce
Picea engelmannii Engelmann spruce
Picea engelmannii var. engelmannii Engelmann spruce
Picea glauca white spruce
Picea glehnii Glehn's spruce
Picea jezoensis Yezo spruce
Picea mariana double spruce
Picea obovata Siberian spruce
Picea omorika Serbian spruce
Picea orientalis Oriental spruce
Picea pungens blue spruce
Picea rubens red spruce
Picea schrenkiana Schrenk's spruce
Picea sitchensis Sitka spruce
Picradeniopsis oppositifolia
Picrasma quassioides India quassiawood
Picris hieracioides
Pieris floribunda flutterbush
Pieris japonica Japanese pieris
Pilea fontana lesser clearweed
Pilea pumila dwarf clearweed
Pilosella aurantiaca devil's paintbrush
Pilosella officinarum mouseear hawkweed
Pilosella piloselloides king devil hawkweed
Pilosella praealta tall king devil
Pilosella Xfloribunda pale hawkweed
Pimpinella saxifraga solidstem burnet saxifrage
Pinckneya bracteata fevertree
Pinguicula ionantha
Pinguicula primuliflora
Pinguicula villosa hairy butterwort
Pinguicula vulgaris common butterwort
Pinus albicaulis whitebark pine
Pinus aristata Rocky Mountain bristlecone pine
Pinus arizonica Arizona pine
Pinus armandii Armand pine
Pinus attenuata knobcone pine
Pinus balfouriana foxtail pine
Pinus banksiana jack pine
Pinus bungeana Bunge's pine
Pinus cembra Swiss stone pine
Pinus cembroides Mexican piñon
Pinus clausa sand pine
Pinus contorta lodgepole pine
Pinus contorta var. contorta shore pine
Pinus contorta var. latifolia lodgepole pine
Pinus coulteri Coulter's pine
Pinus densiflora Japanese red pine
Pinus echinata southern pine
Pinus edulis American piñon
Pinus elliottii slash pine
Pinus engelmannii Arizona longleaf pine
Pinus flexilis Rocky Mountain white pine
Pinus glabra spruce pine
Pinus heldreichii Heldreich pine
Pinus jeffreyi Truckee pine
Pinus koraiensis cedar pine
Pinus lambertiana big sugar pine
Pinus leiophylla var. chihuahuana Chihuahua pine
Pinus longaeva Great Basin bristlecone pine
Pinus monophylla oneleaf pinyon
Pinus monticola western white pine
Pinus mugo scrub mountain pine
Pinus mugo subsp. mugo mugho pine
Pinus muricata bishop pine
Pinus nigra Austrian pine
Pinus nigra subsp. nigra Austrian pine
Pinus nigra subsp. salzmanii Pyrenees pine
Pinus palustris longleaf pine
Pinus parviflora five-needle pine
Pinus peuce Balkan pine
Pinus ponderosa Sierra brownbark pine
Pinus pumila dwarf Siberian pine
Pinus pungens Table Mountain pine
Pinus radiata Monterey pine
Pinus resinosa red pine
Pinus rigida northern pitch pine
Pinus sabiniana foothills pine
Pinus serotina pond pine
Pinus sibirica Siberian cedar
Pinus strobiformus Mexican white pine
Pinus strobus Weymouth pine
Pinus sylvestris Caledonian pine
Pinus taeda Arkansas pine
Pinus thunbergii Japanese black pine
Pinus torreyana subsp. insularis island Torrey pine
Pinus torreyana subsp. torreyana Del Mar pine
Pinus virginiana cedar pine
Pinus wallichiana Himalayan white pine
Piptatherum canadense Richardson's feathergrass
Piptatherum exiguum little ricegrass
Piptatherum micranthum smallflowered ricegrass
Piptatherum pungens sharp piptatherum
Piptatherum racemosum mountain ricegrass
Piptochaetium avenaceum blackseed speargrass
Pisum sativum
Pittosporum tenuifolium tawhiwhi
Pityopsis falcata
Plagiobothrys figuratus subsp. figuratus fragrant popcornflower
Plagiobothrys leptocladus finebranched popcornflower
Plagiobothrys scouleri Scouler's popcornflower
Plagiobothrys scouleri var. hispidulus sleeping popcornflower
Planera aquatica water elm
Plantago aristata largebract plantain
Plantago canescens hairy plantain
Plantago cordata kingroot
Plantago elongata slender plantain
Plantago eriopoda saline plantain
Plantago lanceolata ripplegrass
Plantago macrocarpa Alaska plantain
Plantago major whiteman's foot
Plantago maritima seaside plantain
Plantago maritima subsp. juncoides goosetongue
Plantago media hoary plantain
Plantago patagonica woolly plantain
Plantago psyllium sand plantain
Plantago rugelii blackseed plantain
Plantago virginica Virginia plantain
Platanthera aquilonis leafy northern green orchid
Platanthera blephariglottis whitefringed orchid
Platanthera blephariglottis var. blephariglottis whitefringed orchid
Platanthera chorisiana Chamisso's orchid
Platanthera ciliaris yellowfringed orchid
Platanthera clavellata clubspur orchid
Platanthera cristata
Platanthera dilatata tall white bog orchid
Platanthera dilatata var. dilatata tall white bog orchid
Platanthera elegans subsp. elegans elegant rein orchid
Platanthera flava tubercled orchid
Platanthera flava var. flava southern tubercled orchid
Platanthera flava var. herbiola small palegreen orchis
Platanthera grandiflora large butterfly orchid
Platanthera hookeri Hooker's orchid
Platanthera huronensis tall northern green orchid
Platanthera integra
Platanthera integrilabia
Platanthera lacera green fringed orchid
Platanthera leucophaea prairie white fringed orchid
Platanthera macrophylla Goldie's roundleaf orchid
Platanthera obtusata oneleaf rein orchid
Platanthera orbiculata large roundleaf orchid
Platanthera orbiculata var. orbiculata
Platanthera peramoena
Platanthera praeclara Great Plains white fringed orchid
Platanthera psycodes small butterfly orchid
Platanthera stricta slender rein orchid
Platanthera unalascensis Alaskan rein orchid
Platanthera Xandrewsii Andrews' hybrid orchid
Platanus occidentalis American sycamore
Platanus racemosa western sycamore
Platanus Xhispanica mapleleaf planetree
Platycladus orientalis Chinese arborvitae
Platycodon grandiflorus balloon flower
Pleuropogon sabinei Sabine's semaphoregrass
Pleurozium schreberi Schreber's moss
Pluchea odorata
Pluchea odorata var. succulenta
Poa abbreviata subsp. pattersonii Patterson's bluegrass
Poa alpina alpine bluegrass
Poa alsodes grove bluegrass
Poa annua low speargrass
Poa arctica arctic bluegrass
Poa arctica subsp. arctica arctic bluegrass
Poa arida prairie bluegrass
Poa bulbosa bulbous bluegrass
Poa compressa wiregrass
Poa cusickii Cusick's bluegrass
Poa fendleriana longtongue muttongrass
Poa glauca glaucous bluegrass
Poa glauca subsp. glauca upland bluegrass
Poa glauca subsp. rupicola timberline bluegrass
Poa hartzii Hartz's bluegrass
Poa interior interior bluegrass
Poa laxa subsp. banffiana Banff bluegrass
Poa laxa subsp. fernaldiana Mount Washington bluegrass
Poa laxiflora laxflower bluegrass
Poa leptocoma western bog bluegrass
Poa lettermanii Letterman's bluegrass
Poa macrantha dune bluegrass
Poa marcida weeping bluegrass
Poa nemoralis woodland bluegrass
Poa nervosa veiny bluegrass
Poa paludigena
Poa palustris fowl bluegrass
Poa paucispicula Alaska bluegrass
Poa porsildii Porsild's bluegrass
Poa pratensis Kentucky bluegrass
Poa pratensis subsp. alpigena alpine meadowgrass
Poa pratensis subsp. angustifolia narrowleaf meadowgrass
Poa pratensis subsp. irrigata spreading bluegrass
Poa pratensis subsp. pratensis Kentucky bluegrass
Poa pseudoabbreviata polar bluegrass
Poa saltuensis drooping bluegrass
Poa saltuensis subsp. languida oldpasture bluegrass
Poa secunda Sandberg's bluegrass
Poa secunda subsp. juncifolia alkali bluegrass
Poa secunda subsp. secunda Pacificbluegrass
Poa stenantha narrowflower bluegrass
Poa suksdorfii western bluegrass
Poa sylvestris woodland bluegrass
Poa trivialis rough meadowgrass
Poa wheeleri Wheeler's bluegrass
Podagrostis humilis alpine bentgrass
Podistera yukonensis Yukon podistera
Podophyllum hexandrum Chinese may apple
Podophyllum peltatum Mayapple
Podostemum ceratophyllum threadfoot
Pogogyne floribunda
Pogonia ophioglossoides rose pogonia
Polanisia dodecandra roughseed clammyweed
Polanisia dodecandra subsp. dodecandra
Polemonium acutiflorum tall Jacob's-ladder
Polemonium boreale arctic Jacob's ladder
Polemonium caeruleum Jacob's ladder
Polemonium micranthum annual Jacob's-ladder
Polemonium occidentale western polemonium
Polemonium pauciflorum yellow Jacob's ladder
Polemonium pulcherrimum showy Jacob's-ladder
Polemonium pulcherrimum subsp. pulcherrimum showy Jacob's-ladder
Polemonium reptans creeping Jacob's ladder
Polemonium reptans var. reptans creeping Jacob's-ladder
Polemonium vanbruntiae Van Brunt's Jacob's-ladder
Polemonium viscosum sticky Jacob's-ladder
Polemonium yezoense Japanese Jacob's ladder
Polycnemum majus giant needleleaf
Polygala ambigua obscure milkwort
Polygala chaemaebuxus evergreen milkvetch
Polygala cruciata crossleaf milkwort
Polygala hookeri
Polygala incarnata procession flower
Polygala nuttallii
Polygala polygama racemed milkwort
Polygala sanguinea field milkwort
Polygala senega Seneca snakeroot
Polygala subspinosa
Polygala verticillata whorled milkwort
Polygaloides paucifolia fringed polygala
Polygonatum biflorum giant Solomon's seal
Polygonatum biflorum subsp. commutatum giant Solomon's seal
Polygonatum biflorum subsp. melleum honeyflower Solomon's seal
Polygonatum humile dwarf Japanese Solomon's seal
Polygonatum multiflorum Eurasian Solomon's seal
Polygonatum odoratum fragrant Solomon's seal
Polygonatum pubescens hairy Solomon's seal
Polygonatum Xhybridum garden Solomon's seal
Polygonella basiramia
Polygonella macrophylla
Polygonella myriophylla
Polygonum achoreum striate knotweed
Polygonum articulatum coastal jointweed
Polygonum austiniae Mrs. Austin's knotweed
Polygonum aviculare prostrate knotweed
Polygonum aviculare subsp. buxiforme shore knotweed
Polygonum aviculare subsp. depressum ovalleaf knotweed
Polygonum aviculare subsp. neglectum narrowleaf knotweed
Polygonum douglasii Douglas's knotweed
Polygonum erectum erect knotweed
Polygonum fowleri Fowler's knotweed
Polygonum fowleri subsp. hudsonianum Hudsonian knotweed
Polygonum glaucum
Polygonum minimum broadleaf knotweed
Polygonum oxyspermum subsp. raii Ray's knotweed
Polygonum patulum Bellard's smartweed
Polygonum polygaloides subsp. confertiflorum closeflower knotweed
Polygonum ramosissimum yellowflower knotweed
Polygonum ramosissimum subsp. prolificum bushy knotweed
Polygonum ramosissimum subsp. ramosissimum yellowflower knotweed
Polygonum spergulariiforme scatter knotweed
Polymnia canadensis
Polypodium appalachianum Appalachian polypody
Polypodium glycyrrhiza licorice fern
Polypodium hesperium western polypody
Polypodium sibiricum Siberian polypody
Polypodium virginianum rock polypody
Polypogon monspeliensis rabbitsfoot grass
Polystichum acrostichoides Christmas fern
Polystichum braunii Braun's hollyfern
Polystichum californicum California swordfern
Polystichum kruckebergii Kruckeberg's hollyfern
Polystichum lemmonii Lemmon's hollyfern
Polystichum lonchitis northern hollyfern
Polystichum munitum western swordfern
Polystichum scopulinum mountain hollyfern
Polystichum setiferum soft shield fern
Polystichum setigerum Alaskan hollyfern
Polystichum tsus-simense Korean rock fern
Polystichum Xpotteri Potter’s hollyfern
Polytaenia nuttallii Nuttall's prairie parsley
Poncirus trifoliata Japanese bitter orange
Pontederia cordata pickerelweed
Ponthieva racemosa
Populus alba silver poplar
Populus angustifolia narrowleaf balsam poplar
Populus balsamifera balsam poplar
Populus balsamifera subsp. balsamifera balsam poplar
Populus balsamifera subsp. trichocarpa black cottonwood
Populus deltoides eastern cottonwood
Populus deltoides subsp. deltoides eastern cottonwood
Populus deltoides subsp. monilifera plains cottonwood
Populus deltoides subsp. wislizeni Rio Grande cottonwood
Populus grandidentata bigtooth aspen
Populus heterophylla swamp cottonwood
Populus maximowiczii Japanese poplar
Populus nigra black poplar
Populus simonii Simon's poplar
Populus tremula Swedish columnar aspen
Populus tremuloides trembling aspen
Populus X'Brooks' Brooks poplar
Populus Xacuminata waxleaf cottonwood
Populus Xcanadensis Canadian poplar
Populus Xcanescens curly poplar
Populus Xjackii Jack's hybrid poplar
Populus Xrouleauana Rouleau's hybrid poplar
Portulaca grandiflora moss rose
Portulaca oleracea common purslane
Potamogeton alpinus Northern pondweed
Potamogeton amplifolius bigleaf pondweed
Potamogeton bicupulatus two-cupped pondweed
Potamogeton confervoides Tuckerman's pondweed
Potamogeton crispus curlyleaf pondweed
Potamogeton diversifolius waterthread pondweed
Potamogeton epihydrus ribbonleaf pondweed
Potamogeton foliosus leafy pondweed
Potamogeton friesii Fries' pondweed
Potamogeton gramineus grassy pondweed
Potamogeton hillii Hill's pondweed
Potamogeton illinoensis Illinois pondweed
Potamogeton natans broadleaf pondweed
Potamogeton nodosus longleaf pondweed
Potamogeton oakesianus Oakes' pondweed
Potamogeton oblongus oblongleaf pondweed
Potamogeton obtusifolius bluntleaf pondweed
Potamogeton ogdenii Ogden's pondweed
Potamogeton perfoliatus redhead grass
Potamogeton praelongus longstalk pondweed
Potamogeton pulcher heartleaf pondweed
Potamogeton pusillus small pondweed
Potamogeton pusillus subsp. gemmiparus budding pondweed
Potamogeton pusillus subsp. pusillus small pondweed
Potamogeton pusillus subsp. tenuissimus Berchtold's pondweed
Potamogeton richardsonii Richardson's pondweed
Potamogeton robbinsii fern pondweed
Potamogeton spirillus northern snailseed pondweed
Potamogeton strictifolius narrowleaf pondweed
Potamogeton subsibiricus Yenisei River pondweed
Potamogeton vaseyi Vasey's pondweed
Potamogeton Xnitens hybrid pondweed
Potamogeton zosteriformis flatstem pondweed
Potentilla Hybrids (herbaceous types) hybrid cinquefoil
Potentilla anserina silverweed
Potentilla anserina subsp. groenlandica Egede's silverweed
Potentilla argentea hairy cinquefoil
Potentilla atrosanguinea ruby cinquefoil
Potentilla bimundorum staghorn cinquefoil
Potentilla bipinnatifida plains cinquefoil
Potentilla canadensis Canada cinquefoil
Potentilla crantzii alpine cinquefoil
Potentilla gracilis slender cinquefoil
Potentilla gracilis var. fastigiata slender cinquefoil
Potentilla gracilis var. gracilis slender cinquefoil
Potentilla hippiana woolly cinquefoil
Potentilla hippiana var. hippiana
Potentilla inclinata ashy cinquefoil
Potentilla intermedia downy cinquefoil
Potentilla megalantha strawberry cinquefoil
Potentilla nana polar cinquefoil
Potentilla nepalensis Nepal cinquefoil
Potentilla neumanniana spring cinquefoil
Potentilla nivea snowy cinquefoil
Potentilla norvegica rough cinquefoil
Potentilla norvegica subsp. monspeliensis
Potentilla norvegica subsp. norvegica
Potentilla pensylvanica coastal cinquefoil
Potentilla pensylvanica var. litoralis coastal cinquefoil
Potentilla pulchella pretty cinquefoil
Potentilla pulcherrima beautiful cinquefoil
Potentilla recta upright cinquefoil
Potentilla reptans creeping cinquefoil
Potentilla rivalis riverbank cinquefoil
Potentilla rubricaulis Rocky Mountain cinquefoil
Potentilla simplex oldfield cinquefoil
Potentilla subjuga Colorado cinquefoil
Potentilla supina subsp. paradoxa paradox cinquefoil
Potentilla thurberi scarlet cinquefoil
Potentilla vahliana Vahl’s cinquefoil
Potentilla villosa villous cinquefoil
Poteridium sanguisorba var. polygamum garden burnet
Primula auricula
Primula conjugens var. conjugens slim-pod shootingstar
Primula denticulata drumstick primrose
Primula egaliksensis bog primrose
Primula farinosa bird's-eye primrose
Primula florindae Tibetan primrose
Primula incana silvery primrose
Primula japonica candelabra primula
Primula jeffreyi Sierra shooting star
Primula laurentiana birdseye primrose
Primula marginata
Primula matthioli alpine bells
Primula meadia shootingstar
Primula mistassinica Mistassini primrose
Primula pauciflora prairie shooting star
Primula pauciflora var. cusickii Cusick's shootingstar
Primula pauciflora var. pauciflora darkthroat shootingstar
Primula rosea pink primrose
Primula sieboldii Japanese primrose
Primula stricta coastal primrose
Primula veris English cowslip
Primula vialii Chinese pagoda primrose
Primula vulgaris English primrose
Primula Xbulleesiana candelabra primrose
Primula Xpolyantha hybrid English primrose
Primula Xpruhoniciana juliana hybrid primrose
Primula Xpubescens auricula hybrid primrose
Prinsepia sinensis cherry prinsepia
Prinsepia uniflora hedge prinsepia
Prosartes hookeri Hooker's mandarin
Prosartes lanuginosa yellow fairybells
Prosartes maculata nodding mandarin
Prosartes trachycarpa roughfruit fairybells
Proserpinaca palustris marsh mermaidweed
Proserpinaca pectinata combleaf mermaidweed
Prosopis glandulosa var. glandulosa honey mesquite
Prosopis glandulosa var. torreyana western honey mesquite
Prosopis pubescens screwpod
Prosopis velutina velvet mesquite
Prunella vulgaris healall
Prunella vulgaris subsp. lanceolata healall
Prunella vulgaris subsp. vulgaris healall
Prunus alleghaniensis
Prunus alleghaniensis var. davisii
Prunus americana American plum
Prunus armeniaca Siberian apricot
Prunus avium sweet cherry
Prunus cerasifera cherry plum
Prunus cerasus pie cherry
Prunus domestica Damson plum
Prunus domestica subsp. italica greengage
Prunus emarginata bitter cherry
Prunus geniculata
Prunus glandulosa Chinese bush cherry
Prunus humilis Chinese plum cherry
Prunus incisa Fuji cherry
Prunus laurocerasus cherry laurel
Prunus lusitanica Portugese laurel
Prunus maackii Amur chokecherry
Prunus mahaleb Mahaleb cherry
Prunus mandshurica Manchurian apricot
Prunus maritima beach plum
Prunus nigra Canada plum
Prunus padus European bird cherry
Prunus pensylvanica pincherry
Prunus persica common peach
Prunus pumila Great Lakes sand cherry
Prunus pumila var. besseyi Bessey's cherry
Prunus pumila var. depressa dwarf sand cherry
Prunus pumila var. pumila dwarf cherry
Prunus pyrifolia Chinese sand pear
Prunus salicina Japanese plum
Prunus sargentii northern Japanese hill cherry
Prunus serotina wild black cherry
Prunus serrula birch-bark cherry
Prunus serrulata Mt. Fuji cherry
Prunus spinosa blackthorn
Prunus subhirtella weeping Higan cherry
Prunus susquehanae Susquehana sand cherry
Prunus tenella dwarf Russian almond
Prunus tomentosa Manchu cherry
Prunus triloba f lowering plum
Prunus virginiana bitter cherry
Prunus virginiana var. demissa western choke cherry
Prunus virginiana var. virginiana bitter cherry
Prunus Xcistena dwarf redleaf plum
Prunus yedoensis Yoshino cherry
Psephellus dealbatus pink cornflower
Psephellus hypoleucus pink cornflower
Pseudocydonia sinensis Chinese quince
Pseudofumaria alba white corydalis
Pseudofumaria lutea golden corydalis
Pseudognaphalium macounii clammy everlasting
Pseudognaphalium obtusifolium sweet everlasting
Pseudolarix amabilis golden larch
Pseudorchis straminea Newfoundland orchid
Pseudoroegneria spicata beardless wheatgrass
Pseudosasa japonica Japanese arrow bamboo
Pseudotsuga macrocarpa bigcone spruce
Pseudotsuga menziesii Douglas fir
Pseudotsuga menziesii var. glauca Rocky Mountain Douglas fir
Pseudotsuga menziesii var. menziesii common Douglas fir
Psilocarphus brevissimus dwarf woollyheads
Psilocarphus brevissimus var. brevissimus dwarf woollyheads
Psilocarphus tenellus slender woollyheads
Ptelea trifoliata common hoptree
Ptelea trifoliata subsp. trifoliata common hoptree
Pteridium aquilinum eastern bracken fern
Pteridium aquilinum var. latiusculum eastern bracken
Pterocarya rhoifolia Japanese wingnut
Pterocarya stenoptera Chinese wingnut
Pteroceltis tatarinowii winged hackberry
Pteroglossaspis ecristata
Pterospora andromedea woodland pinedrops
Pterostyrax corymbosus little epaulettetree
Pterostyrax hispida fragrant epaulette tree
Ptilimnium nodosum harperella
Ptilium crista-castrensis plume moss
Puccinellia andersonii Anderson's alkaligrass
Puccinellia angustata narrow alkaligrass
Puccinellia distans relaxed saltmarsh grass
Puccinellia distans subsp. hauptiana Haupt's alkaligrass
Puccinellia nutkaensis weeping alkali-grass
Puccinellia nuttalliana Nuttall's goose grass
Puccinellia phryganodes creeping goose grass
Puccinellia pumila smooth alkali grass
Puccinellia tenella Lange's alkali grass
Puccinellia vahliana Vahl's alkaligrass
Pueraria montana var. lobata kudzu
Pulmonaria 'Excalibur' hybrid lungwort
Pulmonaria Hybrids - others not listed here hybrid lungwort
Pulmonaria angustifolia blue cowslip
Pulmonaria longifolia narrowleaf lungwort
Pulmonaria mollis large lungwort
Pulmonaria rubra Bethlehem sage
Pulmonaria saccharata Bethlehem sage
Purshia tridentata antelope bitterbrush
Puschkinia scilloides striped squill
Pycnanthemum incanum
Pycnanthemum muticum mountain mint
Pycnanthemum tenuifolium slenderleaf mountain mint
Pycnanthemum verticillatum
Pycnanthemum verticillatum var. pilosum hairy mountain mint
Pycnanthemum virginianum Virginia mountain mint
Pyracantha coccinea scarlet firethorn
Pyrola americana roundleaf pyrola
Pyrola asarifolia pink pyrola
Pyrola chlorantha greenflowered pyrola
Pyrola elliptica shinleaf
Pyrola grandiflora arctic pyrola
Pyrola minor lesser pyrola
Pyrola picta white-veined pyrola
Pyrrocoma insecticruris
Pyrrocoma liatriformis
Pyrrocoma lucida
Pyrrocoma radiata
Pyrus calleryana Bradford pear
Pyrus communis common pear
Pyrus fauriei fauriei pear
Pyrus pyrifolia Chinese sand pear
Pyrus salicifolia willowleaf pear
Pyrus ussuriensis Harbin pear
Pyxidanthera brevifolia Sandhills pyxie-moss