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Paeoniaceae

• Paeonia brownii — western peony

Pallaviciniaceae

• Moerckia blyttii
• Moerckia hibernica

• Pallavicinia lyellii — pallavicinia

Papaveraceae

• Meconella oregana — white meconella
• Papaver alboroseum — pale poppy
• Papaver alpinum — dwarf poppy
• Papaver dahlianum — polar poppy
• Papaver gorodkovii — Russian poppy
• Papaver lapponicum — Lapland poppy
• Papaver macounii — Macoun's poppy

• Papaver mcconnellii — McConnell's poppy
• Papaver nudicaule — Icelandic poppy
• Papaver pygmaeum — alpine glacier poppy
• Papaver radicatum — Arctic poppy
• Papaver walpolei — Walpole's poppy
• Sanguinaria canadensis — bloodroot
• Stylophorum diphyllum — celandine poppy

Pelliaceae

• Pellia endiviifolia
• Pellia epiphylla — common pellia

• Pellia neesiana

Phytolaccaceae

• Phytolacca americana — common pokeweed

Pinaceae

• Abies amabilis — Pacific silver fir
• Abies balsamea — balsam fir
• Abies grandis — grand fir
• Abies lasiocarpa — subalpine fir
• Abies x phanerolepis
• Larix laricina — tamarack
• Larix lyallii — subalpine larch
• Larix occidentalis — western larch
• Picea engelmannii — Engelmann's spruce
• Picea glauca — white spruce
• Picea mariana — black spruce
• Picea rubens — red spruce
• Picea sitchensis — Sitka spruce
• Picea x lutzii
• Pinus albicaulis — whitebark pine

• Pinus banksiana — jack pine
• Pinus contorta — lodgepole pine
• Pinus flexilis — limber pine
• Pinus monticola — western white pine
• Pinus ponderosa — ponderosa pine
• Pinus resinosa — red pine
• Pinus rigida — pitch pine
• Pinus strobus — eastern white pine
• Pinus x murraybanksiana
• Pseudotsuga menziesii — Douglas-fir
• Tsuga canadensis — eastern hemlock
• Tsuga heterophylla — western hemlock
• Tsuga mertensiana — mountain hemlock

Plagiochilaceae

• Pedinophyllum interruptum
• Plagiochila arctica
• Plagiochila asplenioides
• Plagiochila austinii

• Plagiochila porelloides
• Plagiochila satoi
• Plagiochila schoefieldiana
• Plagiochila semidecurrens

Plagiotheciaceae

• Plagiothecium berggrenianum
• Plagiothecium cavifolium
• Plagiothecium denticulatum
• Plagiothecium laetum

• Plagiothecium latebricola — lurking leskea
• Plagiothecium piliferum
• Plagiothecium undulatum

Plantaginaceae

• Littorella uniflora — American shoregrass
• Plantago bigelovii — Bigelow's plantain
• Plantago canescens — hairy plantain
• Plantago cordata — heartleaf plantain
• Plantago elongata — slender plantain
• Plantago eriopoda — saline plantain

• Plantago macrocarpa — Alaska plantain
• Plantago maritima — seaside plantain
• Plantago patagonica — woolly plantain
• Plantago rugelii — blackseed plantain
• Plantago tweedyi — Tweedy's plantain

Pleuroziaceae

• Pleurozia purpurea

Pleuroziopsidaceae

• Pleuroziopsis ruthenica

Plumbaginaceae

• Armeria maritima — western thrift

• Limonium carolinianum — sea-lavender

Poaceae

• Achnatherum hymenoides — Indian mountain-ricegrass
• Achnatherum lemmonii — Lemmon's needlegrass
• Achnatherum nelsonii — Nelson's needlegrass
• Achnatherum occidentale — western needlegrass
• Achnatherum richardsonii — Canada mountain-ricegrass
• Agrostis aequivalvis — northern bentgrass
• Agrostis alascana — Alaska bentgrass
• Agrostis clavata — clubbed bentgrass
• Agrostis diegoensis — leafy bentgrass
• Agrostis exarata — spike bentgrass
• Agrostis geminata — hairgrass
• Agrostis humilis — mountain bentgrass
• Agrostis hyemalis — winter bentgrass
• Agrostis idahoensis — Idaho bentgrass
• Agrostis mertensii — Arctic bentgrass
• Agrostis microphylla — small-leaf bentgrass
• Agrostis oregonensis — Oregon bentgrass
• Agrostis pallens — seashore bentgrass
• Agrostis perennans — perennial bentgrass
• Agrostis scabra — rough bentgrass
• Agrostis stolonifera — creeping bentgrass
• Agrostis thurberiana — Thurber's bentgrass
• Agrostis variabilis — variable bentgrass
• Alopecurus aequalis — shortawn foxtail
• Alopecurus alpinus — mountain foxtail
• Alopecurus carolinianus — tufted foxtail
• Ammophila breviligulata — American beachgrass
• Andropogon gerardii — big bluestem
• Andropogon hallii — sand bluestem
• Andropogon virginicus — common broom-sedge
• Arctagrostis latifolia — broadleaf arctagrostis
• Arctophila fulva — pendant-grass
• Aristida basiramea — forked three-awn grass
• Aristida dichotoma — Shinner's three-awn grass
• Aristida longespica — slimspike three-awn grass
• Aristida purpurascens — purple needlegrass
• Aristida purpurea — purple three-awn grass
• Beckmannia syzigachne — American sloughgrass
• Bouteloua curtipendula — side-oats gramma
• Bouteloua gracilis — blue gramma
• Bouteloua hirsuta — hairy gramma
• Brachyelytrum erectum — bearded shorthusk
• Brachyelytrum septentrionale — northern shorthusk
• Bromus anomalus — nodding brome
• Bromus carinatus — California brome
• Bromus ciliatus — fringed brome
• Bromus inermis — awnless brome
• Bromus kalmii — wild chess
• Bromus latiglumis — broad-glumed brome
• Bromus nottowayanus — Nottoway brome
• Bromus pacificus — Pacific brome
• Bromus porteri — Porter's chess
• Bromus pubescens — hairy wood brome
• Bromus sitchensis — Alaska brome
• Bromus vulgaris — narrow-flowered brome
• Buchloe dactyloides — buffalo grass
• Calamagrostis canadensis — bluejoint reedgrass
• Calamagrostis coarctata — Nuttall's reedgrass
• Calamagrostis deschampsioides — circumpolar small-reedgrass
• Calamagrostis holmii — Holm's small-reedgrass
• Calamagrostis lapponica — Lapland reedgrass
• Calamagrostis montanensis — plains reedgrass
• Calamagrostis nutkaensis — Pacific small-reedgrass
• Calamagrostis pickeringii — Pickering's reed bentgrass
• Calamagrostis purpurascens — purple reedgrass
• Calamagrostis rubescens — pine reedgrass
• Calamagrostis sesquiflora — one-and-a-half-flower small-reedgrass
• Calamagrostis stricta — slimstem small-reedgrass
• Calamovilfa longifolia — sand reedgrass
• Catabrosa aquatica — brook grass
• Cenchrus longispinus — longspine sandbur
• Chasmanthium latifolium — Indian sea-oats
• Cinna arundinacea — stout wood reedgrass
• Cinna latifolia — slender wood reedgrass
• Coleanthus subtilis — moss grass
• Danthonia californica — California oatgrass
• Danthonia compressa — flattened oatgrass
• Danthonia intermedia — Vasey's oatgrass
• Danthonia parryi — Parry's oatgrass
• Danthonia spicata — poverty oatgrass
• Danthonia unispicata — few-flowered oatgrass
• Deschampsia alpina — alpine hairgrass
• Deschampsia beringensis — Bering hairgrass
• Deschampsia brevifolia — shortleaf hairgrass
• Deschampsia caespitosa — tufted hairgrass
• Deschampsia danthonioides — annual hairgrass
• Deschampsia elongata — slender hairgrass
• Deschampsia flexuosa — wavy hairgrass
• Deschampsia holciformis — Pacific hairgrass
• Deschampsia mackenzieana — MacKenzie's hairgrass
• Diarrhena americana — American beakgrain
• Diarrhena obovata — beak grass
• Dichanthelium acuminatum — tapered rosette grass
• Dichanthelium boreale — northern witchgrass
• Dichanthelium boscii — Bosc's witchgrass
• Dichanthelium clandestinum — deer-tongue witchgrass
• Dichanthelium depauperatum — starved witchgrass
• Dichanthelium dichotomum — cypress witchgrass
• Dichanthelium latifolium — broadleaf witchgrass
• Dichanthelium leibergii — Leiberg's rosette grass
• Dichanthelium leucothrix — roughish witchgrass
• Dichanthelium linearifolium — slimleaf witchgrass
• Dichanthelium longiligulatum — coastal plain witchgrass
• Dichanthelium meridionale — matting witchgrass
• Dichanthelium oligosanthes — Heller's witchgrass
• Dichanthelium ovale — egg-leaf witchgrass
• Dichanthelium sabulorum — hemlock witchgrass
• Dichanthelium scabriusculum — woolly witchgrass
• Dichanthelium sphaerocarpon — roundfruit panicgrass
• Dichanthelium spretum — Eaton's witchgrass
• Dichanthelium villosissimum — whitehair witchgrass
• Dichanthelium wilcoxianum — Wilcox' panicgrass
• Dichanthelium xanthophysum — slender dichanthelium
• Digitaria cognata — mountain hairgrass
• Distichlis spicata — seashore saltgrass
• Dupontia fisheri — Fisher's dupontia
• Echinochloa muricata — rough barnyard grass
• Echinochloa walteri — Walter's barnyard grass
• Elymus alaskanus — Alaska wild rye
• Elymus albicans — Montana wild rye
• Elymus calderi — Calder's wild rye
• Elymus canadensis — nodding wild rye
• Elymus diversiglumis — interrupted wild rye
• Elymus elymoides — bottlebrush squirrel-tail
• Elymus glaucus — smooth wild rye
• Elymus hirsutus — boreal wild rye
• Elymus hystrix — bottlebrush grass
• Elymus lanceolatus — streamside wild rye
• Elymus macrourus — thickspike wild rye
• Elymus riparius — river wild rye
• Elymus scribneri — Scribner's wild rye
• Elymus sibiricus — Siberian wild rye
• Elymus submuticus — wild rye
• Elymus trachycaulus — slender wild rye
• Elymus villosus — hairy wild rye
• Elymus virginicus — Virginia wild rye
• Elymus vulpinus — Rydberg's wild rye
• Elymus wiegandii — Wiegand's wild rye
• Elymus x dorei — Dore's wild rye
• Elymus x ebingeri — Ebinger's wild rye
• Elymus x hansenii — Hansen's wild rye
• Elymus x maltei — Malte's wild rye
• Elymus x mossii — Moss' wild rye
• Elymus x palmerensis — Palmer's wild rye
• Elymus x pseudorepens — quackgrass
• Eragrostis capillaris — tiny lovegrass
• Eragrostis frankii — Frank's lovegrass
• Eragrostis hypnoides — teal lovegrass
• Eragrostis pectinacea — purple lovegrass
• Eragrostis spectabilis — purple lovegrass
• Festuca altaica — rough fescue
• Festuca baffinensis — Baffin fescue
• Festuca brachyphylla — shortleaf fescue
• Festuca brevissima — Alaska fescue
• Festuca campestris — blue rough fescue
• Festuca edlundiae — Arctic festuca
• Festuca frederikseniae — North Atlantic fescue
• Festuca hallii — Hall's rough fescue
• Festuca heteromalla — spreading fescue
• Festuca hyperborea — boreal fescue
• Festuca idahoensis — Idaho fescue
• Festuca lenensis — tundra fescue
• Festuca minutiflora — smallflower fescue
• Festuca occidentalis — western fescue
• Festuca richardsonii — Richardson's fescue
• Festuca rubra — red fescue
• Festuca saximontana — Rocky Mountain fescue
• Festuca subulata — nodding fescue
• Festuca subuliflora — crinkle-awn fescue
• Festuca subverticillata — nodding fescue
• Festuca viridula — mountain fescue
• Festuca viviparoidea — northern fescue
• Glyceria borealis — small floating mannagrass
• Glyceria canadensis — Canada mannagrass
• Glyceria elata — tall mannagrass
• Glyceria grandis — American mannagrass
• Glyceria laxa — northern mannagrass
• Glyceria leptostachya — slimhead mannagrass
• Glyceria melicaria — slender mannagrass
• Glyceria obtusa — blunt mannagrass

• Glyceria occidentalis — northwestern mannagrass
• Glyceria pulchella — MacKenzie Valley mannagrass
• Glyceria septentrionalis — floating mannagrass
• Glyceria striata — fowl mannagrass
• Glyceria x gatineauensis — Gatineau mannagrass
• Helictotrichon hookeri — spike-oat
• Hesperostipa comata — needle-and-thread
• Hesperostipa curtiseta — western porcupine grass
• Hesperostipa spartea — porcupine needlegrass
• Hierochloe alpina — alpine sweet grass
• Hierochloe hirta — northern sweet grass
• Hierochloe odorata — vanilla grass
• Hierochloe pauciflora — Arctic sweet grass
• Hordeum brachyantherum — meadow barley
• Hordeum jubatum — foxtail barley
• Hordeum pusillum — little barley
• Koeleria asiatica — Oriental junegrass
• Koeleria macrantha — prairie junegrass
• Leersia oryzoides — rice cutgrass
• Leersia virginica — Virginia cutgrass
• Leymus cinereus — Great Basin lyme grass
• Leymus innovatus — northwestern wildrye
• Leymus mollis — sea lyme grass
• Leymus triticoides — beardless lyme grass
• Leymus x vancouverensis — Vancouver Island lyme grass
• Melica bulbosa — western melicgrass
• Melica fugax — small melicgrass
• Melica harfordii — Harford's melicgrass
• Melica hitchcockii — Alberta melicgrass
• Melica smithii — Smith's melicgrass
• Melica spectabilis — showy melicgrass
• Melica subulata — Alaska onion grass
• Milium effusum — tall millet grass
• Monroa squarrosa — munro grass
• Muhlenbergia andina — foxtail muhly
• Muhlenbergia asperifolia — alkali muhly
• Muhlenbergia cuspidata — plains mühlenbergia
• Muhlenbergia filiformis — Pullup muhly
• Muhlenbergia frondosa — wirestem muhly
• Muhlenbergia glomerata — marsh muhly
• Muhlenbergia mexicana — Mexican muhly
• Muhlenbergia racemosa — green muhly
• Muhlenbergia richardsonis — softleaf muhly
• Muhlenbergia schreberi — Schreiber's muhly
• Muhlenbergia sobolifera — cliff muhly
• Muhlenbergia sylvatica — woodland muhly
• Muhlenbergia tenuiflora — slender muhly
• Muhlenbergia uniflora — fall dropseed muhly
• Nassella viridula — green needlegrass
• Oryzopsis asperifolia — white-grained mountain-ricegrass
• Panicum capillare — old witch panicgrass
• Panicum dichotomiflorum — spreading panicgrass
• Panicum flexile — wiry witch grass
• Panicum gattingeri — Gattinger's panicgrass
• Panicum philadelphicum — Philadelphia panicgrass
• Panicum rigidulum — redtop panicgrass
• Panicum virgatum — old switch panicgrass
• Pascopyrum smithii — western wheatgrass
• Paspalum setaceum — slender paspalum
• Phalaris arundinacea — reed canarygrass
• Phippsia algida — ice grass
• Phippsia concinna — snow grass
• Phleum alpinum — mountain timothy
• Phragmites australis — common reed
• Piptatherum canadense — Canada mountain ricegrass
• Piptatherum exiguum — little ricegrass
• Piptatherum micranthum — little mountain-ricegrass
• Piptatherum pungens — slender mountain-ricegrass
• Piptatherum racemosum — blackfruit mountain-ricegrass
• Piptochaetium avenaceum — blackseed needlegrass
• Pleuropogon refractus — nodding false semaphore grass
• Pleuropogon sabinei — sabine-grass
• Poa abbreviata — northern bluegrass
• Poa alpina — alpine bluegrass
• Poa alsodes — grove meadow grass
• Poa arctica — Arctic bluegrass
• Poa arida — prairie bluegrass
• Poa confinis — dune bluegrass
• Poa cusickii — Cusick's bluegrass
• Poa eminens — largeflower bluegrass
• Poa fendleriana — muttongrass
• Poa flexuosa — flexible bluegrass
• Poa gaspensis — Gaspé Peninsula bluegrass
• Poa glauca — white bluegrass
• Poa hartzii — Hartz' bluegrass
• Poa howellii — Howell's bluegrass
• Poa interior — inland bluegrass
• Poa laxa — Mt. Washington bluegrass
• Poa laxiflora — loose-flowered bluegrass
• Poa leibergii — Leiberg's bluegrass
• Poa leptocoma — bog bluegrass
• Poa lettermanii — Letterman's bluegrass
• Poa macrantha — sand-dune bluegrass
• Poa marcida — weak bluegrass
• Poa nemoralis — woods bluegrass
• Poa nervosa — Hooker's bluegrass
• Poa palustris — fowl bluegrass
• Poa porsildii — Porsild's bluegrass
• Poa pratensis — Kentucky bluegrass
• Poa pseudoabbreviata — polar bluegrass
• Poa reflexa — nodding bluegrass
• Poa saltuensis — drooping bluegrass
• Poa secunda — curly bluegrass
• Poa stenantha — narrowflower bluegrass
• Poa suksdorfii — western bluegrass
• Poa sylvestris — woodland bluegrass
• Poa tolmatchewii — Tolmatchew's bluegrass
• Poa wheeleri Wheeler's bluegrass
• Poa x limosa — Lassen County bluegrass
• Pseudoroegneria spicata — Bluebunch wheatgrass
• Puccinellia agrostidea — tundra alkali grass
• Puccinellia ambigua — Alberton alkali grass
• Puccinellia americana — American alkali grass
• Puccinellia andersonii — Anderson's alkali grass
• Puccinellia angustata — northern alkali grass
• Puccinellia arctica — Arctic alkali grass
• Puccinellia bruggemannii — Prince Patrick alkali grass
• Puccinellia deschampsioides — polar alkali grass
• Puccinellia distans — spreading alkali grass
• Puccinellia fasciculata — saltmarsh goosegrass
• Puccinellia grandis — Pacific alkali grass
• Puccinellia interior — inland alkali grass
• Puccinellia kurilensis — dwarf alkali grass
• Puccinellia laurentiana — Tracadigash Mountain alkali grass
• Puccinellia lemmonii — Lemmon's alkali grass
• Puccinellia lucida — shining alkali grass
• Puccinellia macra — Bonaventure Island alkali grass
• Puccinellia nutkaensis — Alaska alkali grass
• Puccinellia nuttalliana — Nuttall's alkali grass
• Puccinellia phryganodes — creeping alkali grass
• Puccinellia poacea — floodplain alkali grass
• Puccinellia tenella — tundra alkali grass
• Puccinellia vaginata — Arctic tussock alkali grass
• Puccinellia vahliana — Vahl's alkali grass
• Schedonnardus paniculatus — tumble grass
• Schizachne purpurascens — purple oat
• Schizachyrium scoparium — little bluestem
• Scolochloa festucacea — sprangletop
• Sorghastrum nutans — yellow Indiangrass
• Spartina alterniflora — saltwater cordgrass
• Spartina gracilis — alkali cordgrass
• Spartina patens — saltmeadow cordgrass
• Spartina pectinata — freshwater cordgrass
• Spartina x caespitosa — marsh cordgrass
• Sphenopholis intermedia — slender wedgescale
• Sphenopholis nitida — shiny wedgegrass
• Sphenopholis obtusata — prairie wedgegrass
• Sporobolus airoides — alkali sacaton
• Sporobolus compositus — tall dropseed
• Sporobolus cryptandrus — sand dropseed
• Sporobolus heterolepis — northern dropseed
• Sporobolus neglectus — small dropseed
• Sporobolus vaginiflorus — sheathed dropseed
• Torreyochloa pallida — pale manna grass
• Triplasis purpurea — purple sandgrass
• Trisetum canescens — nodding trisetum
• Trisetum melicoides — purple false oats
• Trisetum montanum — mountain oats
• Trisetum sibiricum — Siberian false oats
• Trisetum spicatum — narrow false oats
• Trisetum wolfii — beardless oats
• Vahlodea atropurpurea — mountain hairgrass
• Vulpia microstachys — small six-weeks grass
• Vulpia octoflora — slender eight-flowered fescue
• Zizania aquatica — eastern wild rice
• Zizania palustris — northern wild rice
• x Agroelymus bowdenii
• x Dupoa labradorica
• x Elyhordeum chatangensis
• x Elyhordeum macounii
• x Elyhordeum montanense
• x Elyhordeum schaackianum
• x Elyleymus colvillensis
• x Elyleymus hirtiflorus
• x Elyleymus jamesensis
• x Elyleymus turneri
• x Elyleymus uclueletensis
• x Elyleymus ungavensis
• x Pucciphippsia vacillans

Podostemaceae

• Podostemum ceratophyllum — threadfoot

Polemoniaceae

• Collomia grandiflora — largeflower collomia
• Collomia heterophylla — varied-leaved collomia
• Collomia linearis — narrow-leaved collomia
• Collomia tenella — diffuse collomia
• Gilia sinuata — rosy gilia
• Gilia tenerrima — delicate gilia
• Ipomopsis aggregata — scarlet skyrocket
• Ipomopsis minutiflora — smallflower standing-cypress
• Leptodactylon pungens — granite prickly-phlox
• Linanthus bicolor — bicoloured desert-gold
• Linanthus harknessii — harkness linanthus
• Linanthus septentrionalis — northern desert-gold
• Navarretia divaricata — mountain navarretia
• Navarretia intertexta — needleleaf navarretia
• Navarretia leucocephala — whiteflower navarretia
• Navarretia squarrosa — skunkweed
• Phlox alyssifolia — alyssum-leaf phlox
• Phlox caespitosa — carpet phlox

• Phlox diffusa — spreading phlox
• Phlox divaricata — wild blue phlox
• Phlox gracilis — slender phlox
• Phlox hoodii — Hood's phlox
• Phlox longifolia — longleaf phlox
• Phlox maculata — northern meadow phlox
• Phlox richardsonii — Richardson's phlox
• Phlox sibirica — Siberian phlox
• Phlox speciosa — showy phlox
• Polemonium acutiflorum — tall Jacob's-ladder
• Polemonium boreale — northern Jacob's-ladder
• Polemonium californicum — California polemonium
• Polemonium elegans — elegant polemonium
• Polemonium micranthum — annual polemonium
• Polemonium occidentale — western Jacob's-ladder
• Polemonium pulcherrimum — showy Jacob's-ladder
• Polemonium vanbruntiae — bog Jacob's-ladder
• Polemonium viscosum — skunk polemonium

Polygalaceae

• Polygala alba — white milkwort
• Polygala incarnata — pink milkwort
• Polygala paucifolia — gaywing milkwort
• Polygala polygama — racemed milkwort

• Polygala sanguinea — field milkwort
• Polygala senega — Seneca snakeroot
• Polygala verticillata — whorled milkwort

Polygonaceae

• Eriogonum androsaceum — rock-jasmine wild buckwheat
• Eriogonum cernuum — nodding wild buckwheat
• Eriogonum flavum — yellow wild buckwheat
• Eriogonum heracleoides — parsnip-flower wild buckwheat
• Eriogonum niveum — snow wild buckwheat
• Eriogonum ovalifolium — oval-leaf buckwheat
• Eriogonum pauciflorum — smallflower wild buckwheat
• Eriogonum pyrolifolium — pyrola-leaved wild buckwheat
• Eriogonum strictum — blue mountain wild buckwheat
• Eriogonum umbellatum — sulphur-flower wild buckwheat
• Koenigia islandica — island kœnigia
• Oxyria digyna — mountain-sorrel
• Polygonella articulata — eastern jointweed
• Polygonum achoreum — leathery knotweed
• Polygonum alpinum — alpine smartweed
• Polygonum amphibium — water smartweed
• Polygonum arifolium — halberd-leaf tearthumb
• Polygonum bellardii — narrowleaf knotweed
• Polygonum bistorta — meadow bistort
• Polygonum bistortoides — American bistort
• Polygonum boreale — northern knotweed
• Polygonum buxiforme — Small's knotweed
• Polygonum careyi — Carey's smartweed
• Polygonum caurianum — Alaska knotweed
• Polygonum cilinode — fringed black-bindweed
• Polygonum douglasii — Douglas' knotweed
• Polygonum erectum — erect knotweed
• Polygonum fowleri — Fowler's knotweed
• Polygonum franktonii — Nova Scotia knotweed
• Polygonum hudsonianum — Hudson Bay knotweed
• Polygonum hydropiper — marshpepper smartweed

• Polygonum hydropiperoides — mild water-pepper
• Polygonum lapathifolium — dockleaf smartweed
• Polygonum minimum — leafy dwarf knotweed
• Polygonum oxyspermum — sharpfruit knotweed
• Polygonum paronychia — beach knotweed
• Polygonum pensylvanicum — Pennsylvania smartweed
• Polygonum polygaloides — white-margin knotweed
• Polygonum punctatum — dotted smartweed
• Polygonum raii — Ray's knotweed
• Polygonum ramosissimum — bushy knotweed
• Polygonum robustius — stout smartweed
• Polygonum sagittatum — arrowleaf tearthumb
• Polygonum scandens — climbing false buckwheat
• Polygonum tenue — slender knotweed
• Polygonum virginianum — Virginia knotweed
• Polygonum viviparum — viviparous knotweed
• Rumex acetosa — garden sorrel
• Rumex altissimus — tall dock
• Rumex aquaticus — western dock
• Rumex arcticus — Arctic dock
• Rumex beringensis — Bering Sea dock
• Rumex maritimus — seaside dock
• Rumex occidentalis
• Rumex orbiculatus — water dock
• Rumex pallidus — seabeach dock
• Rumex paucifolius — alpine sheep sorrel
• Rumex salicifolius — willow dock
• Rumex venosus — veined dock
• Rumex verticillatus — swamp dock
• Rumex x alexidis
• Rumex x franktonis — Frankton's dock

Polypodiaceae

• Polypodium amorphum — irregular polypody
• Polypodium appalachianum — Appalachian rockcap fern
• Polypodium glycyrrhiza — licorice fern
• Polypodium hesperium — western polypody

• Polypodium scouleri — coast polypody
• Polypodium sibiricum — Siberian polypody
• Polypodium virginianum — rock polypody
• Polypodium x incognitum

Polytrichaceae

• Atrichum altecristatum
• Atrichum angustatum
• Atrichum crispum
• Atrichum haussknechtii
• Atrichum oerstedianum
• Atrichum selwynii
• Atrichum tenellum
• Atrichum undulatum — wavy catherinea
• Bartramiopsis lescurii
• Oligotrichum aligerum
• Oligotrichum falcatum
• Oligotrichum hercynicum
• Oligotrichum parallelum
• Pogonatum brachyphyllum — haircap
• Pogonatum contortum
• Pogonatum dentatum — haircap
• Pogonatum pensilvanicum

• Pogonatum urnigerum — haircap
• Polytrichastrum alpinum — alpine polytrichastrum moss
• Polytrichum commune — common haircap moss
• Polytrichum formosum
• Polytrichum hyperboreum
• Polytrichum juniperinum — juniper moss
• Polytrichum longisetum — haircap
• Polytrichum lyallii
• Polytrichum ohioense
• Polytrichum pallidisetum
• Polytrichum piliferum — hairmoss
• Polytrichum sexangulare
• Polytrichum sphaerothecium
• Polytrichum strictum — bog haircap moss
• Polytrichum swartzii
• Psilopilum cavifolium
• Psilopilum laevigatum

Pontederiaceae

• Heteranthera dubia — grassleaf mud-plantain

• Pontederia cordata — pickerelweed

Porellaceae

• Porella cordaeana
• Porella navicularis
• Porella pinnata

• Porella platyphylla
• Porella platyphylloidea
• Porella roellii

Portulacaceae

• Calandrinia ciliata — red maids
• Cistanthe tweedyi — Tweedy's bitterroot
• Cistanthe umbellata — Mount Hood pussy-paws
• Claytonia caroliniana — Carolina spring-beauty
• Claytonia cordifolia — heartleaf spring-beauty
• Claytonia exigua — serpentine spring-beauty
• Claytonia lanceolata — lanceleaf spring-beauty
• Claytonia megarhiza — alpine spring-beauty
• Claytonia ogilviensis — Ogilve Mountain spring-beauty
• Claytonia parviflora — littleflower spring-beauty
• Claytonia perfoliata — miner's-lettuce
• Claytonia rubra — redstem spring-beauty
• Claytonia sarmentosa — Alaska spring-beauty
• Claytonia scammaniana — Scamman's spring-beauty
• Claytonia sibirica — Siberian spring-beauty
• Claytonia tuberosa — tuber spring-beauty

• Claytonia virginica — narrowleaf spring-beauty
• Claytonia washingtoniana — Washington spring-beauty
• Lewisia columbiana — Columbian bitterroot
• Lewisia pygmaea — alpine bitterroot
• Lewisia rediviva — Oregon bitterroot
• Lewisia triphylla — three-leaf bitterroot
• Montia bostockii — Bostock's miner's-lettuce
• Montia chamissoi — Chamisso's miner's-lettuce
• Montia dichotoma — dwarf miner's-lettuce
• Montia diffusa — diffuse montia
• Montia fontana — fountain miner's-lettuce
• Montia howellii — Howell's miner's-lettuce
• Montia linearis — linearleaf miner's-lettuce
• Montia parvifolia — littleleaf miner's-lettuce
• Talinum sediforme — Okanogan flameflower

Potamogetonaceae

• Potamogeton alpinus — northern pondweed
• Potamogeton amplifolius — largeleaf pondweed
• Potamogeton bicupulatus — snail-seed pondweed
• Potamogeton confervoides — algæ-like pondweed
• Potamogeton epihydrus — Nuttall's pondweed
• Potamogeton filiformis — slender pondweed
• Potamogeton foliosus — leafy pondweed
• Potamogeton friesii — Fries' pondweed
• Potamogeton gramineus — grassy pondweed
• Potamogeton hillii — Hill's pondweed
• Potamogeton illinoensis — Illinois pondweed
• Potamogeton methyensis — Methy Lake pondweed
• Potamogeton natans — floating pondweed
• Potamogeton nodosus — longleaf pondweed
• Potamogeton oakesianus — Oakes' pondweed
• Potamogeton oblongus — cinnamon-spot pondweed
• Potamogeton obtusifolius — bluntleaf pondweed
• Potamogeton ogdenii — Ogden's pondweed
• Potamogeton pectinatus — Sago pondweed
• Potamogeton perfoliatus — claspingleaf pondweed
• Potamogeton praelongus — whitestem pondweed
• Potamogeton pulcher — spotted pondweed

• Potamogeton pusillus — slender pondweed
• Potamogeton richardsonii — redheadgrass
• Potamogeton robbinsii — flatleaf pondweed
• Potamogeton spirillus — spiral pondweed
• Potamogeton strictifolius — straightleaf pondweed
• Potamogeton subsibiricus — Yenisei River pondweed
• Potamogeton vaginatus — sheathed pondweed
• Potamogeton vaseyi — Vasey's pondweed
• Potamogeton x faxonii — Faxon's pondweed
• Potamogeton x griffithii — Griffith's pondweed
• Potamogeton x hagstroemii — Hagstrøm's pondweed
• Potamogeton x haynesii — Haynes' pondweed
• Potamogeton x nericus
• Potamogeton x nitens
• Potamogeton x saxonicus — Saxon pondweed
• Potamogeton x schreberi — Schreiber's pondweed
• Potamogeton x scoliophyllus
• Potamogeton x sparganiifolius
• Potamogeton x spathuliformis
• Potamogeton x suecicus
• Potamogeton zosteriformis — flatstem pondweed

Pottiaceae

• Acaulon muticum
• Acaulon triquetrum
• Aloina bifrons
• Aloina brevirostris
• Aloina rigida
• Anoectangium aestivum
• Anoectangium tenuinerve
• Astomum muehlenbergianum
• Astomum phascoides
• Barbula amplexifolia
• Barbula convoluta
• Barbula coreensis
• Barbula eustegia
• Barbula indica
• Barbula unguiculata
• Bryoerythrophyllum columbianum
• Bryoerythrophyllum ferruginascens
• Bryoerythrophyllum recurvirostre
• Crossidium aberrans
• Crossidium seriatum
• Crumia latifolia
• Desmatodon cernuus
• Desmatodon convolutus
• Desmatodon guepinii
• Desmatodon heimii
• Desmatodon latifolius
• Desmatodon laureri
• Desmatodon leucostoma
• Desmatodon obtusifolius
• Desmatodon porteri
• Desmatodon randii
• Desmatodon systylius
• Didymodon asperifolius
• Didymodon fallax
• Didymodon johansenii
• Didymodon leskeoides
• Didymodon michiganensis
• Didymodon nevadensis
• Didymodon nigrescens
• Didymodon rigidulus
• Didymodon subandreaeoides
• Didymodon tophaceus
• Didymodon vinealis
• Eucladium verticillatum — lime-seep eucladium
• Geheebia gigantea
• Gymnostomum aeruginosum
• Gymnostomum calcareum
• Gyroweisia reflexa
• Gyroweisia tenuis
• Hymenostylium insigne
• Hymenostylium recurvirostre — hymenostylium moss

• Hyophila involuta — hyophila moss
• Molendoa sendtneriana
• Oxystegus spiralis
• Oxystegus tenuirostris
• Paraleptodontium recurvifolium
• Phascum cuspidatum
• Phascum floerkeanum
• Phascum vlassovii
• Pleurochaete squarrosa
• Pottia bryoides
• Pottia davalliana
• Pottia intermedia
• Pottia nevadensis
• Pottia truncata
• Pottia wilsonii
• Pseudocrossidium revolutum
• Pterygoneurum kozlovii
• Pterygoneurum lamellatum
• Pterygoneurum ovatum
• Pterygoneurum subsessile
• Stegonia latifolia
• Stegonia pilifera
• Timmiella crassinervis
• Tortella arctica
• Tortella fragilis
• Tortella humilis
• Tortella inclinata
• Tortella tortelloides
• Tortella tortuosa — twisted moss
• Tortula amplexa
• Tortula bartramii
• Tortula bolanderi
• Tortula brevipes
• Tortula cainii
• Tortula caninervis — tortula moss
• Tortula laevipila
• Tortula latifolia
• Tortula mucronifolia
• Tortula muralis
• Tortula norvegica
• Tortula papillosa
• Tortula papillosissima
• Tortula princeps
• Tortula ruralis — tortula moss
• Tortula scotteri
• Tortula subulata
• Trichostomopsis australasiae
• Trichostomum arcticum
• Trichostomum crispulum
• Weissia controversa
• Weissia hedwigii

Primulaceae

• Anagallis minima — chaffweed
• Androsace chamaejasme — sweetflower rock-jasmine
• Androsace filiformis — slender rock-jasmine
• Androsace occidentalis — western rock-jasmine
• Androsace septentrionalis — pygmyflower rock-jasmine
• Dodecatheon conjugens — Bonneville shootingstar
• Dodecatheon dentatum — white shootingstar
• Dodecatheon frigidum — northern shootingstar
• Dodecatheon hendersonii — Henderson's shootingstar
• Dodecatheon jeffreyi — Jeffrey's shootingstar
• Dodecatheon meadia — shootingstar
• Dodecatheon pulchellum — few-flower shootingstar
• Douglasia alaskana — Alaska rock-jasmine
• Douglasia arctica — MacKenzie's river douglasia
• Douglasia gormanii — Gorman's douglasia
• Douglasia laevigata — cliff douglasia
• Douglasia montana — mountain douglasia
• Douglasia ochotensis — Alaska douglasia
• Glaux maritima — sea milkwort
• Lysimachia ciliata — fringed loosestrife

• Lysimachia hybrida — lanceleaf loosestrife
• Lysimachia lanceolata — lanceleaf loosestrife
• Lysimachia quadriflora — four-flower loosestrife
• Lysimachia quadrifolia — whorled yellow loosestrife
• Lysimachia terrestris — swamp loosestrife
• Lysimachia thyrsiflora — water loosestrife
• Lysimachia x commixta
• Lysimachia x producta
• Primula borealis — slender primrose
• Primula cuneifolia — wedgeleaf primrose
• Primula egaliksensis — Greenland primrose
• Primula eximia — Arctic primrose
• Primula incana — Jones' primrose
• Primula laurentiana — St. Lawrence primrose
• Primula mistassinica — bird's-eye primrose
• Primula nutans — sleepy primrose
• Primula stricta — stiff primrose
• Samolus valerandi — Valerand's brookweed
• Trientalis borealis — northern starflower
• Trientalis europaea — Arctic starflower

Pseudolepicoleaceae

• Blepharostoma trichophyllum

Pteridaceae

• Adiantum aleuticum — Aleutian maidenhair fern
• Adiantum capillus-veneris — southern maidenhair fern
• Adiantum pedatum — northern maidenhair fern
• Adiantum viridimontanum — green mountain maidenhair fern
• Aspidotis densa — Indian's-dream
• Cheilanthes feei — Fee's lipfern
• Cheilanthes gracillima — lace lipfern

• Cryptogramma acrostichoides — American rockbrake
• Cryptogramma cascadensis — Cascade rockbrake
• Cryptogramma sitchensis — Sitka rockbrake
• Cryptogramma stelleri — fragile rockbrake
• Pellaea atropurpurea — purplestem rockbrake
• Pellaea gastonyi — Gastony's rockbrake
• Pellaea glabella — smooth rockbrake
• Pentagramma triangularis — western gold fern

Pterigynandraceae

• Heterocladium dimorphum
• Heterocladium macounii
• Heterocladium procurrens
• Iwatsukiella leucotricha

• Myurella julacea
• Myurella sibirica
• Myurella tenerrima
• Pterigynandrum filiforme

Ptilidiaceae

• Ptilidium ciliare — northern naugehyde liverwort

• Ptilidium pulcherrimum

Ptychomitriaceae

• Campylostelium saxicola — rock-loving swan-necked moss

• Ptychomitrium gardneri
• Ptychomitrium incurvum

Pyrolaceae

• Chimaphila maculata — spotted wintergreen
• Chimaphila menziesii — Menzies' wintergreen
• Chimaphila umbellata — common wintergreen
• Moneses uniflora — one-flower wintergreen
• Orthilia secunda — one-side wintergreen
• Pyrola americana — American wintergreen

• Pyrola asarifolia — pink wintergreen
• Pyrola chlorantha — greenflower wintergreen
• Pyrola elliptica — shinleaf
• Pyrola grandiflora — Arctic wintergreen
• Pyrola minor — lesser wintergreen
• Pyrola picta — whitevein wintergreen