Vascular Plants

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Scientific names beginning with A:
Abies amabilisPacific silver fir
Distribution: On both sides of the Cascades in Washington; Alaska south to Siskiyou County, California, mostly west of the Cascade Crest.
Habitat: Mostly at 1000-4000 feet elevation in the mountains.
Abies grandisgrand fir
Distribution: Both sides of the Cascades in Washington; Vancouver Island, British Columbia south to California on both sides of the Cascades; scattered areas in the mountains east to Montana.
Habitat: Coniferous forests, from sea level to mid-elevations in the mountains.
Abies lasiocarpaalpine fir, subalpine fir
Distribution: Widely distributed throughout much of Washington; Alaska south to southern Oregon, east in the higher mountains to Alberta, Canada, and Colorado.
Habitat: Subalpine to alpine slopes, where commonly in krumholtz form.
Abies proceranoble fir
Distribution: Chiefly west of the Cascades in Washington; from northern Washington to the Siskiyou Mountains in California, and in the Coast Range in Oregon.
Habitat: Deep forests where there is sufficient moisture, moderate to fairly high elevations.
Abronia latifoliayellow sand-verbena
Distribution: West of the Cascades in Washington along the coast; Vancouver Island, British Columbia south to California.
Habitat: Coastal beaches and sand dunes.
Abronia melliferahoney-scented sand-verbena, white sand verbena
Distribution: Distributed east of the Cascades in Washington in the Columbia Basin and along the Snake River; north-central Oregon, southeastern Oregon and adjacent Idaho, southeastern Idaho and adjacent Wyoming.
Habitat: Dunes and sandy soil at low elevations.
Abronia umbellata
Distribution: Distributed along the coast in Washington; along the coast from British Columbia south to Baja California.
Habitat: Coastal sandy beaches and adjacent dunes.
Abutilon theophrastivelvetleaf
Distribution: Both sides of the Cascades in Washington; introduced noxious weed, common in eastern United States, uncommon in the Pacific Northwest.
Habitat: Rich, moist soils in gardens, cultivated fields and waste areas.
Acer circinatumvine maple
Distribution: Both sides of the Cascades in Washington; Alaska south to northern California.
Habitat: Moist woods from sea level to mid-elevations in the mountains.
Acer glabrum
Distribution: Widely distributed throughout Washington; Alaska south to California, east to the Rockies and Nebraska.
Habitat: Moist woods from sea level to mid-elevations in the mountains.
var. douglasii – Douglas maple
Acer macrophyllumbig-leaf maple
Distribution: Both sides of the Cascades in Washington; Alaska south to northern California.
Habitat: Moist woods from sea level to mid-elevations in the mountains.
Acer negundo
Distribution: Chiefly east of the Cascades in Washington; widely distributed throughout North America.
Habitat: Occasionally escapes from cultivation, chiefly in disturbed areas or riparian zones.
var. negundo – box elder
var. violaceum – box elder
Acer platanoidesNorway maple
Distribution: Introduced in scattered localities throughout Washington; east to Idaho, and in northeastern United States.
Habitat: Escapes from cultivation.
Acer pseudoplatanussycamore maple
Distribution: Introduced in northeastern United States
Habitat: Rarely escapes from cultivation in the Pacific Northwest
Acer saccharinumsilver maple
Distribution: Increasingly common east of the Cascades, occasional west of the Cascades; introduced as an ornamental from eastern and central North America .
Habitat: Moist soil of bottomlands.
Achillea millefoliummilfoil, yarrow
Distribution: Both sides of the Cascades in Washington, from the coast to the alpine; circumboreal; widespread throughout North America.
Habitat: Common in open, dry to somewhat moist areas from low to high elevations; tolerant of disturbance.
Achillea ptarmicapearl yarrow
Distribution: Introduced in Washington to Montana, and northeastern United States
Habitat: Occasionally escaped from cultivation
Achlys californicadeer's-foot
Distribution: On both sides of the Cascades and in the Olympic Mountains in Washington; British Columbia south to California.
Habitat: Moist areas in deep woods to open parks.
Achlys triphylladeerfoot, sweet-after-death, vanillaleaf
Distribution: Both sides of the Cascades in Washington; British Columbia south to California.
Habitat: Moist areas in deep woods to forest openings.
Achnatherum ×bloomeriIndian ricegrass
Achnatherum hendersoniiHenderson's rice grass
Distribution: Yakima and Kittitas counties in Washington; south to Jefferson County, Oregon.
Habitat: Dry, rocky, shallow soil, in sagebrush or ponderosa pine.
Achnatherum hymenoidesIndian rice grass
Distribution: East of the Cascades in Washington; British Columbia south to California, east to Alberta and the Dakotas and Texas.
Habitat: Grasslands, desert plains, and foothills, especially on rocky or sandy soil.
Achnatherum lemmonii
Distribution: Chiefly east of the Cascades in Washington; south-central British Columbia south to California, east to Montana and Arizona.
Habitat: Valleys to mid-elevations in the mountains, often in ponderosa pine forests.
ssp. lemmonii – Lemmon's needlegrass
Achnatherum nelsonii
ssp. dorei – Nelson's needlegrass
Achnatherum occidentale
ssp. californicum – California needlegrass
ssp. pubescens – western needlegrass
Achnatherum richardsoniiRichardson's rice grass
Achnatherum thurberianumThurber's rice grass
Acinos arvensisbasil-thyme
Acmispon americanus
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Montana, south to Mexico
Habitat: Chiefly in sandy to rocky, exposed or wooded areas, more common at low elevations
var. americanus – Spanish-clover, American bird's-foot trefoil
Acmispon denticulatusriver-bar bird's-foot-trefoil
Acmispon nevadensis
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east to Idaho and Nevada.
Habitat: Open, disturbed areas including road cuts, balds, grasslands, and forest edges at low to moderate elevations.
var. nevadensis – Nevada deervetch
Acmispon parviflorusshort-flower bird's-foot-trefoil
Distribution: Occurring chiefly west of the Cascades in Washington and in the Columbia River Gorge; British Columbia south to California.
Habitat: Open slopes and sandy flats, seashore into the mountains.
Aconitum columbianum
Distribution: Alaska to California, east to Montana and New Mexico.
Habitat: Moist woods and meadows, moderate to subalpine elevations.
ssp. columbianum – monkshood
Aconogonon davisiae
Distribution: Cascades and Olympic mountains of Wahington, south to California, east to Idaho and western Montana.
Habitat: Slopes and ridges in the subalpine and alpine.
var. davisiae – Newberry's fleeceflower, Davis's knotweed
Aconogonon phytolaccifolium
Distribution: East of the Cascades in Washington; Alaska south to the Sierra Nevada of California, east to Idaho and western Montana.
Habitat: Subalpine to alpine ridges, meadows and talus slopes.
var. phytolaccifolium – alpine fleeceflower, poke knotweed
Acorus americanusAmerican sweetflag, several-vein sweetflag
Distribution: Very limited distribution in Washington along eastern border with Idaho; widely distributed throughout northern half of North America from Alaska to Newfoundland.
Habitat: Wetlands, lake margins, and riparian zones.
Acorus calamussweet flag
Acroptilon repenshardheads, Russian knapweed, Turkestan thistle
Distribution: Introduced chiefly east of the Cascades in Washington; widely distributed throughout much of North America.
Habitat: Dry, open areas at low elevation and foothills.
Actaea elata
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia south to Oregon.
Habitat: Moist, shady woods at low elevations.
var. elata – tall bugbane
Actaea rubrabaneberry
Distribution: Widely distributed throughout Washington; Alaska south to California, east to the Atlantic Coast.
Habitat: Moist woods and streambanks from low elevations to moderate elevations in the mountains.
Adelinia grandegrand hound's tongue, Pacific hound's tongue
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; Washington south to California.
Habitat: Forest openings and meadows at low to moderate elevations.
Adenocaulon bicolorpathfinder, trailplant
Distribution: Both sides of the Cascades in Washington; British Columbia south to California, east through the Rockies to Wisconsin and Ontario.
Habitat: Moist, shady woods at low to mid-elevations.
Adiantum aleuticumAleutian maidenhair, western maidenhair
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska south to California, east sporadically to the Rocky Mountains, and also in northeastern North America.
Habitat: Moist woods and streambanks, lowlands to mid-elevations in the mountains.
Adonis aestivalissummer pheasant's-eye
Distribution: Introduced and occasionallhy escaping, but marginally persistant; uncommon in the Pacific Northwest.
Habitat: Disturbed areas.
Adonis annuablood-drops
Distribution: Introduced from Europe as an ornamental and occasionaly escaping; uncommon in Washington.
Habitat: Disturbed soil near gardens.
Aegilops cylindricajointed goat grass
Distribution: A weedy plant from Europe, introduced in much of western United States.
Habitat: Waste ground and roadsides; a troublesome weed in wheat.
Aegilops triuncialis
Distribution: Introduced occasionally in western North America; native from Mediterranean to central Asia.
Habitat: Disturbed areas, roadsides, railroad beds
var. triuncialis – barbed goatgrass
Aegopodium podagrariabishop's goutweed
Distribution: Introduced in the Pacific Northwest and much of eastern United States
Habitat: Shady and waste places; a tenacious garden weed
Aesculus hippocastanumhorse-chestnut
Distribution: West of the Cascades in Washington; British Columbia south to Oregon; central and eastern North America.
Habitat: Disturbed forested areas, particularly in urban and suburban areas where the species is planted as a street tree.
Agastache foeniculumblue giant-hyssop
Distribution: Eastern Washington; British Columbia east to Quebec, south to Wyoming and Kentucky.
Habitat: Disturbed areas.
Agastache occidentaliswestern giant-hyssop
Distribution: East slopes of the Cascades, Chelan to Yakima Counties, Washington; south to Oregon.
Habitat: Dry, open, often rocky slopes at low to moderate elevations.
Agastache urticifolianettle-leaf giant-hyssop
Distribution: East of the Cascades in Washington; British Columbia to California, east to Colorado.
Habitat: Dry open slopes and draws, foothills to mid-elevations in the mountains
Ageratina occidentaliswestern boneset, western snakeroot
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Idaho and Utah.
Habitat: Rocky places at various altitudes.
Agoseris apargioides
var. maritima – seaside agoseris
Agoseris aurantiaca
Distribution: Both sides of the Cascades in Washington; Alaska to California, east to Wyoming and New Mexico.
Habitat: Mid- to high elevations in the mountains.
var. aurantiaca – orange agoseris, slender agoseris
var. carnea – pink agoseris
Agoseris elatatall agoseris, tall goat-chicory
Distribution: On both sides of the Cascades in Washington; Washington south to California.
Habitat: Meadows and open woods, from the valleys to moderate elevations in the mountains.
Agoseris glauca
Distribution: Widely distributed throughout Washington; Alaska south to California, east to Michigan and New Mexico.
Habitat: Open forests and open areas, low to high elevations in the mountains.
var. dasycephala – field agoseris, pale goat-chicory
var. glauca – pale agoseris, short beaked agoseris
Agoseris grandiflora
Distribution: Distributed on both sides of the Cascades in Washington; British Columbia to California, east to Idaho and Nevada.
Habitat: Meadows and other open places in the lowlands and at moderate elevations in the mountains, often in dry areas.
var. grandiflora – large flowered agoseris, large flower goat-chicory
var. leptophylla – Puget Sound agoseris
Agoseris heterophyllaannual agoseris
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to California, east to Montana and Arizona.
Habitat: Dry, open areas at low to mid-elevations.
Agoseris monticolamountain agoseris, Sierra Nevada agoseris
Distribution: East of the Cascades in Washington; Washington south to California, east to Nevada.
Habitat: Mesic meadows in the subalpine and alpine.
Agoseris retrorsaspear leaved agoseris, spear leaf goat-chicory
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Nevada, Utah, and Arizona.
Habitat: Shrub-steppe and ponderosa pine forest openings.
Agrimonia gryposepalatall hairy grooveburr
×Agropogon lutosusperennial beardgrass
Agropyron cristatumcrested wheatgrass
Distribution: Introduced for forage purposes in many areas of western United States, becoming widely established.
Habitat: Dry, open areas.
Agrostemma githagocommon corncockle
Distribution: Introduced and well established in Washington; also occurring in Oregon, less common in Idaho and Montana.
Habitat: Roadsides and wasteland.
Agrostis capillariscolonial bent
Distribution: Occurring on both sides of the Cascades crest in Washington; widely introduced throughout North America.
Habitat: Open, disturbed areas often at low elevations.
Agrostis castellanaHighland bent, dryland browntop
Agrostis exarataspiked bent
Distribution: Widely distributed throughout Washington; Alaska south to California, east to Alberta, Nebraska and Texas.
Habitat: Moist areas, from near sea level to mid-elevations in the mountains.
Agrostis giganteablack bent
Distribution: Occurring throughout Washington; found in nearly all parts of North America.
Habitat: Disturbed sites, roadsides, edge of agricultural fields, mostly at low elevations.
Agrostis idahoensisIdaho bent
Agrostis mertensiinorthern bent
Agrostis microphyllasmall-leaf bent
Agrostis oregonensisOregon bent
Agrostis pallensseashore bent
Distribution: Near the coast, Grays Harbor County, Washington south to San Francisco, California.
Habitat: Coastal sand dunes and immediately adjacent woods.
Agrostis scabrarough bent
Agrostis stoloniferaspreading bent
Distribution: Widespread throughout Washington; Alaska south to California; also in Idaho, Utah and Colorado.
Habitat: Wet, disturbed areas that include streambanks, flooded fields, and ditches at low to moderate elevations.
Agrostis variabilisalpine bent
Ailanthus altissimatree-of-heaven
Distribution: Occurring mostly east of the Cascades in Washington, but also in scattered localities west of the Cascades; widely distributed throughout North America.
Habitat: Escaped ornamental in roadsides, waste areas, along railroad tracks, and other open, disturbed areas.
Aira caryophyllea
Distribution: Introduced and common west of the Cascades, British Columbia to California
Habitat: A weed in moist to dry, gravelly soil
var. capillaris – delicate hairgrass
var. caryophyllea – silver hairgrass
Aira praecoxearly silver-hair grass
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia south to California; Nova Scotia south to Virginia in eastern North America.
Habitat: Gravelly prairies, sea bluffs and dunes near the coast, also in other disturbed, open areas at low elevations.
Ajuga reptanscarpet bugle
Distribution: Introduced (and occasionally escaping from cultivation) west of the Cascades in Washington; British Columbia south to Oregon; widespread in central and eastern North America.
Habitat: Disturbed ground, often in forest understory.
Alcea roseahollyhock
Distribution: In a few scattered locations in Washington; widely distributed throughout much of North America.
Habitat: Garden escape establishing in disturbed areas.
Alchemilla vulgariscommon lady's-mantle
Alhagi maurorumcamelthorn
Distribution: East of the Cascades in Washington; south to California, east to Idaho and Texas.
Habitat: Disturbed areas in arid lands.
Aliciella leptomeriaGreat Basin gilia [H&C], sand gily-flower [KZ]
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to the Rocky Mountains.
Habitat: Open, sandy and rocky areas in sagebrush steppe from low to middle elevations.
Aliciella lottiaeLott's gily-flower
Distribution: Occurring east of the Cascades crest in the south-central portion of Washington; Washington south to California, east to Idaho and Utah.
Habitat: Open, sandy areas in sagebrush-steppe at low to middle elevations.
Alisma gramineumgrass-leaved water-plantain, narrow-leaf water-plantain
Distribution: East of the Cascades in Washington; British Columbia south to California, east to Minnesota and Wisconsin
Habitat: Marshy areas, often in standing water.
Alisma plantago-aquaticaEuropean water-plantain
Distribution: Introduced occasionally, known from Seattle, Washington.
Habitat: Marshy areas, sometimes largely submerged
Alisma trivialenorthern water-plantain
Distribution: Widely distributed throughout Washington; Alaska south to California, east across the northern half of North America to Newfoundland.
Habitat: Streams, lakes, ponds, wet ditches, wetlands, and cattle ponds.
Alliaria petiolatagarlic mustard
Distribution: Currently restricted to a few counties west of the Cascades in Washington; Alaska south to Utah, east across Canada and the U.S. to the Atlantic Coast.
Habitat: Disturbed soil and waste ground.
Allium acuminatumtaper-tip onion
Distribution: Widely distributed across Washington; British Columbia south to California, east to Wyoming.
Habitat: Common in dry, open, often rocky areas, low to moderate elevations in the mountains.
Allium amplectensnarrow-leaf onion
Distribution: Scattered locations on both sides of the Cascades crest in Washington; British Columbia south to California.
Habitat: Dry slopes and open meadows at low to moderate elevations.
Allium campanulatumrosy Sierra onion
Distribution: In the mountains in eastern Oregon, California dnd Nevada, and on Bethel Ridge, Yakima County, Washington.
Habitat: Dry soils at medium to high elevations.
Allium cepacultivated onion
Allium cernuumnodding onion
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to Oregon, east to the Rocky Mountains; also in central and southeastern U.S.
Habitat: Open, somewhat moist areas, sea level to high elevations in the mountains.
Allium columbianumColumbia onion
Distribution: Occurring in eastern Washington; Washington east to western Idaho and in western Montana.
Habitat: Shallow soils on rock outcrops and wet meadows.
Allium constrictumGrand Coulee onion
Distribution: Grant and Douglas Counties, Washington.
Habitat: Shallow, vernally-moist soils in low, open areas.
Allium crenulatumOlympic onion, scalloped onion
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to Oregon.
Habitat: Forest openings and mountain meadows, moderate to high elevations.
Allium dictuonBlue Mountain onion
Distribution: Blue Mountains of southeast Washington.
Habitat: Open, fairly dry, rocky areas.
Allium douglasiiDouglas' onion
Distribution: East of the Cascades in Washington; central and eastern Washington south to northeastern Oregon.
Habitat: Open, vernally-moist areas at low to moderate elevations.
Allium fibrillumCuddy Mountain onion, fringed onion
Distribution: Occurring chiefly in the southeastern counties of Washington; Washington east to Montana, south to Oregon.
Habitat: Moist, shallow soils in the mountains.
Allium geyeri
Distribution: From the Cascades east in Washington and northern Idaho; disjunct in South Dakota, Utah and Texas.
Habitat: Low meadows and along streams.
var. geyeri – Geyer's onion
var. tenerum – Rydberg's onion
Allium macrumrock onion
Distribution: In Washington, Kittitas and Douglas Counties south to Walla Walla and Klickitat Counties; more common in north-central Oregon.
Habitat: Lithosol and barren, gravelly soils in the shrub-steppe.
Allium neviiNevius's garlic, Nevius's onion
Distribution: East slope and foothills of the Cascades, Kittitas County, Washington, south to Wasco County, Oregon
Habitat: Open areas where the soil is wet into the spring
Allium robinsoniiRobinson's onion
Distribution: Near the Columbia River in Washington; Washington south to north-central Oregon.
Habitat: Sand and gravel near the river to rocky, even lithosol benches.
Allium sativum
Distribution: West of the Cascades in Washington.
Habitat: Disturbed areas near towns, cities, agricultural fields where cultivated.
var. sativum – garlic
Allium schoenoprasumchives
Distribution: Across southern Canada and northern United States; in Washington, along the Wenatchee and Columbia Rivers
Habitat: Wet meadows, rocky or gravelly streambanks and lake shores
Allium scilloidesfragile onion, scilla-like onion
Distribution: Douglas County to Klickitat County, Washington, lower foothills of the Cascades to east of the Columbia River
Habitat: Scablands and dry, barren, gravelly soils.
Allium textiletextile onion, white wild onion
Allium tolmiei
Distribution: South-east Washington; eastern Oregon, western Idaho and north-east California.
Habitat: Rocky, gravelly or clayey soils, generally with sparse cover.
var. tolmiei – Tolmie's onion
Allium validumPacific onion, swamp onion
Allium vinealewild chives, crow garlic, wild garlic
Distribution: Scattered localities throughout Washington.
Habitat: Disturbed areas.
Allotropa virgatacandystick, sugarstick
Distribution: Both sides of the Cascades in Washington; British Columbia south to California.
Habitat: Deep humus of coniferous forests at low to moderate elevations.
Alnus incana
Distribution: Occurring east of the Cascades crest in Washington; Alaska south to New Mexico, also in the north-central and northeastern region of North America.
Habitat: Moist places, streamside, low to high elevations.
ssp. tenuifolia – mountain alder
Alnus rhombifoliaCalifornia alder, white alder
Distribution: Chiefly east of the Cascades crest in Washington; Washington south to California and Nevada, east to Idaho.
Habitat: Near streams at low elevations.
Alnus rubraOregon alder, red alder
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska south to California, disjunct to the east in northern Idaho.
Habitat: Moist areas at low elevations.
Alnus viridis
Distribution: Widely distributed throughout the mountainous areas of Washington; Alaska south to California, east across the northern half of North America to the Atlantic Coast.
Habitat: Moist areas, low to high elevations.
ssp. fruticosa – Siberian alder
ssp. sinuata – mountain alder, Sitka alder
Alopecurus aequalis
Distribution: Widespread throughout much of Washington; widespread throughout much of North America.
Habitat: Wet places, often submersed.
var. aequalis – shortawn fescue
Alopecurus arundinaceuscreeping meadow-foxtail
Alopecurus carolinianustufted meadow-foxtail
Alopecurus geniculatuswater fescue
Distribution: Distributed on both sides of the Cascades in Washington; Alaska south to California, east to the Atlantic Coast in Canada.
Habitat: Wet places, often in standing water.
Alopecurus myosuroidesslender meadow-foxtail
Distribution: Introduced in many parts of North America; occasional in Washington and Oregon.
Habitat: Wet places.
Alopecurus pratensisfield meadow-foxtail
Distribution: Alaska to Newfoundland, south to Oregon, Idaho, Montana, Missouri, and New Jersey. Found on both sides of the Cascades in WA.
Habitat: Swampy areas in meadows, in irrigated fields, and along roadsides.
Alopecurus saccatusPacific meadow-foxtail
Alstroemeria aureaPeruvian lily
Alyssum alyssoidessmall alison, madwort, pale alyssum madwort
Distribution: Chiefly east of the Cascades in Washington; widely distributed throughout North America except for parts of southeastern U.S.
Habitat: Dry, waste areas, becoming common in the shrub-steppe of eastern Washington.
Alyssum desertorumdesert alyssum
Distribution: East of the Cascades in Washington; widely distributed throughout central and western North America.
Habitat: Dry, open ground, often where disturbed.
Alyssum muraleyellowtuft
Amaranthus albuswhite pigweed, tumbleweed
Distribution: Occurring east of the Cascades crest in Washington; widely distributed throughout much of North America.
Habitat: Dry, disturbed areas.
Amaranthus blitoidesmatweed, prostrate pigweed
Distribution: Introduced in the Pacific Northwest; more common east of the Cascades
Habitat: Dry, disturbed areas
Amaranthus blitumlivid amaranth, pale amaranth
Amaranthus californicusCalifornia amaranth
Distribution: Occurring in south-central and southeastern Washington; Alberta to California, east to the Great Plains.
Habitat: Seasonally moist flats and shorelines, wastelots, and other disturbed areas;
Amaranthus cruentusblood amaranth, caterpillar amaranth, purple amaranth
Amaranthus hybridusgreen amaranth, hybrid amaranth, smooth amaranth, green pigweed, smooth pigweed
Distribution: Found in much of the United States, but uncommon in the Pacific Northwest; collected in Whitman County
Habitat: Dry areas, disturbed sites, agricultural fields.
Amaranthus powelliigreen amaranth, Powell's amaranth
Distribution: Introduced in much of the United States; common in the Pacific Northwest
Habitat: Disturbed areas
Amaranthus retroflexusredroot pigweed, rough pigweed
Distribution: In scattered locations throughout Washington, but more commonly east of the Cascade crest; widely distributed throughout much of North America.
Habitat: Disturbed areas.
Amaranthus tuberculatusrough-fruited waterhemp, tall waterhemp
Distribution: Cosmopolitan weed found throughout North America.
Habitat: Moist or wet disturbed areas, particularly in association with agriculture or roadsides.
Ambrosia acanthicarpaflat spine bur-ragweed, annual bursage, bur ragweed
Distribution: Chiefly east of the Cascades, but widespread in western United States, to Texas and the Dakotas
Habitat: Weedy native in dry areas at low elevations
Ambrosia artemisiifoliaannual ragweed, common ragweed
Distribution: Throughout the United States and the Pacific Northwest
Habitat: Drier areas at low elevations
Ambrosia chamissonissilver beachweed, beach bur, cutleaf beach bur, silver burr-ragweed
Distribution: Maritime shoreline from British Columbia to california
Habitat: Common on sandy beaches above high tide level
Ambrosia psilostachyaperennial ragweed, western ragweed
Distribution: Occurring in the eastern portion of Washington; widely distributed throughout North America except for Alaska and far northern Canada.
Habitat: Waste ground.
Ambrosia trifidagiant ragweed
Distribution: Native and widespread in central and eastern United States; an occasional introduction in the Pacific Northwest.
Habitat: Waste places, usually in moist soil.
Amelanchier alnifoliasaskatoon, serviceberry; saskatoon, Cusick's serviceberry, Saskatoon serviceberry, western serviceberry, humptulips western seviceberry
Distribution: Occurring throughout Washington; Alaska to California, east to the Dakotas and New Mexico.
Habitat: Open woods, canyons and hillsides, sea level to subalpine.
Amelanchier utahensisUtah serviceberry
Distribution: Occurring east of the Cascades crest in Washington; Washington south to Baja California, east to the Rocky Mountains.
Habitat: Rimrock, valleys, gullies and hillsides, from sagebrush desert to mid-elevations in the mountains.
Ammannia coccineavalley redstem
Distribution: Known only from a restoration site in King County; California east along Mexican border to central and eastern U.S.
Habitat: Restored wetland.
Ammannia robustawestern ammania, grand redstem
Distribution: Occurring east of the Cascades crest in Washington; widely distributed from the tropics to much of North America.
Habitat: Wet places, often where alkaline.
Ammophila arenaria
Distribution: Introduced along the Pacific coast from southeast Washington the California.
Habitat: Sandy beaches and dunes.
ssp. arenaria – European beach grass
Ammophila breviligulata
ssp. breviligulata – American beachgrass
Amorpha fruticosafalse indigo-bush
Distribution: Occurring chiefly east of the Cascades crest and along the Columbia River in Washington; widely distributed throughout much of North America except extreme northwest corner.
Habitat: Disturbed areas, roadsides, wastelots, and often along streams and in canyons.
Amphiscirpus nevadensisNevada bulrush
Amsinckia lycopsoidesbugloss fiddleneck, tarweed fiddleneck
Distribution: Chiefly east of the Cascades crest in Washington, with scattered localities west of the crest; east to the Atlantic Coast.
Habitat: Dry, open areas at low elevations.
Amsinckia menziesii
Distribution: Widespread in Washington; Alaska south to California, east to the Rocky Mountains, in scattered localities east of the Rocky Mountains to the Atlantic Coast.
Habitat: Moderately dry areas at low to mid-elevations.
var. intermedia – fireweed fiddleneck, Menzie's fiddleneck, rancher's fiddleneck, small-flowered fiddleneck
var. menziesii – harvest fiddleneck, rigid fiddleneck, rancher's fireweed
Amsinckia spectabilis
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to California.
Habitat: Coastal dunes or sandy bluffs.
var. spectabilis – woolly breeches, Scouler's fiddleneck, seaside fiddleneck
Amsinckia tessellata
Distribution: Chiefly east of the Cascades in Washington; British Columbia south to California, east to Idaho, south to New Mexico.
Habitat: Roadsides and dry, open slopes and flats, often in disturbed soil.
var. tessellata – tessellate fiddleneck
Anagallis arvensisscarlet pimpernel
Distribution: Scattered locations on both sides of the Cascades in Washington; widely distributed throughout North America.
Habitat: Weed of disturbed open areas, waste ground.
Anaphalis margaritaceapearly everlasting
Distribution: Widely distributed throughout Washington; occurring throughout North America except for portions of central and southeastern U.S.
Habitat: Dry to somewhat moist open areas, low to mid-elevations.
Anchusa azureaItalian alkanet, Italian bugloss
Distribution: Scattered localities in Washington; British Columbia south to California, scattered localities east of the Cascades to the Atlantic Coast.
Habitat: Disturbed soil.
Anchusa officinaliscommon alkanet, common bugloss
Distribution: Occurring in scattered locations throughout Washington, but mostly east of the Cascades; occurring throught much of western North America, the upper Midwest, and northeastern U.S.
Habitat: Disturbed areas.
Andromeda polifolia
Distribution: Likely in northern Washington; Alaska to Newfoundland, south in the U.S. to Idaho.
Habitat: Sphagnum bogs and other acidic wetlands.
var. polifolia – bog rosemary
Andropogon gerardiibig bluestem
Androsace filiformisslender-stem rock-jasmine
Androsace septentrionalisnorthern fairy-candelabra, rock jasmine, pygmyflower
Distribution: Northern Washington; circumpolar in the arctic, widespread in Canada, pacific coast of the United States east to Dakotas, Minnesota, and Texas.
Habitat: Alpine meadows.
Anemone deltoideathreeleaf anemone, Columbian windflower
Distribution: On both sides of the Cascades in the southern half of Washington; Washington south to California.
Habitat: Moist to drier areas in open to deep woods at low to moderate elevations.
Anemone drummondii
Distribution: Occurring in the Olympic and Cascade Mountains in Washington; Alaska south to California, east to Montana.
Habitat: Alpine and subalpine regions.
var. drummondii – Drummond's anemone
var. lithophila – Drummonds anemone, little belt mountain anemone
Anemone lyalliilittle mountain anemone, Lyall's anemone
Distribution: Chiefly west of the Cascades but occasionally on the east slope in Washington; British Columbia to California.
Habitat: Open prairies at low elevations to subalpine ridges.
Anemone multifida
Distribution: Alaska to California, east to Nebraska and New Mexico in the west, and across the northern tier of states to Maine
Habitat: From the foothills to high elevations in the mountains
var. multifida – cliff anemone, Pacific anemone
var. saxicola – hirsute anemone
Anemone occidentaliswestern pasqueflower
Distribution: In the Olympic and the Cascade mountains in Washington; British Columbia south to California, east to Montana and the Wallowa Mountains of Oregon.
Habitat: Mountain slopes and meadows at mid- to high elevations.
Anemone oregana
Distribution: In Washington occurring on the Olympic Peninsula and chiefly east of the Cascades crest; Chelan County, Washington south to northern California.
Habitat: Moist, open woods, moderate to mid-elevations in the mountains.
var. felix – Oregon anemone, western wood anemone
var. oregana – Oregon anemone, western wood anemone
Anemone parvifloranorthern anemone, small-flowered anemone
Distribution: Occurring in scattered locaions in Washington; Alaska south to the Cascades of northern Washington, east to the Atlantic Coast, south in the Rocky Mountains to Colorado.
Habitat: Mountain meadows and subalpine stream banks.
Anemone patens
Distribution: East of the Cascades crest in Washington; Alaska south to the Wenatchee Mountains of Washington, east to the Rocky Mountains and northern Great Plains.
Habitat: Prairies to mountain slopes, mostly on well-drained soil.
var. multifida – cliff anemone
Anemone piperiPiper's anemone, Piper's windflower
Distribution: East of the Cascades in Washington;Washington to northeast Oregon east to Idaho and western Montana.
Habitat: Shady woods at moderate to mid-elevations in the mountains.
Angelica argutaLyall's angelica, sharptooth angelica
Distribution: Both sides of the Cascades in Washington; British Columbia south to California, east to Alberta and Utah.
Habitat: Stream banks, wet meadows, marshes and bottomlands, from the foothills and valleys to moderate elevations in the mountains.
Angelica canbyiCanby's angelica
Angelica genuflexakneeling angelica
Distribution: Chiefly west of the Cascades in Washington; Alaska south to California, east in British Columbia to the Selkirk Mountains.
Habitat: Stream banks, wet meadows and other moist places, moderate to mid-elevations in the mountains.
Angelica hendersoniiHenderson's angelica
Distribution: Coastal Washington; south to California.
Habitat: Coastal bluffs and sand dunes.
Angelica lucidaseacoast angelica, sea-watch
Distribution: West of the Cascades in Washington; margin of the Pacific Basin, from the Kuril Islands to California.
Habitat: Coastal bluffs and beaches in the Pacific Northwest, occasionally inland elsewhere.
Angelica tomentosa
var. hendersonii – woolly angelica
Anisocarpus madioideswoodland tarplant, tarweed, woodland tarweed
Distribution: Southern British Columbia to southern California.
Habitat: Open woods.
Antennaria alpinaalpine pussytoes
Distribution: Chiefly in the Cascades and Olympic Mountains of Washington; Circumboreal, extending south in the high mountains to California and Colorado.
Habitat: Alpine meadows.
Antennaria anaphaloidestall pussytoes
Distribution: Chiefly east of the Cascades, British Columbia to Oregon, east to Montana and Colorado.
Habitat: Hillsides and open woods at moderate elevations in the mountains, occasionally on grassy foothills.
Antennaria corymbosaflat topped pussytoes, meadow pussytoes
Antennaria dimorphacushion pussytoes, low pussytoes
Distribution: British Columbia to southern California, east to Montana, Nebraska and Colorado; east of the Cascades in central and eastern Washington.
Habitat: Dry, open places in lowlands to foothills.
Antennaria flagellarisstoloniferous everlasting, flagellate pussytoes, whip pussytoes
Distribution: East of the Cascades in Washington and Oregon, east to Wyoming
Habitat: Shrub-steppe to dry, open areas at mid-elevations, often in lithosol
Antennaria geyeriGeyer's pussytoes, pinewoods pussytoes
Antennaria howellii
Distribution: British Columbia to Oregon, east to Montana
Habitat: Open woods at low to moderate elevations; not common.
ssp. howellii – Howell's pussytoes
ssp. neodioica – field pussytoes
ssp. petaloidea – Blue Mountains everlasting
Antennaria lanatawoolly everlasting, woolly pussytoes
Distribution: Both sides of the Cascades in Washington; British Columbia south to Oregon, east to Alberta and Wyoming.
Habitat: Mountain meadows near timberline.
Antennaria luzuloidessilvery brown everlasting, woodrush pussytoes
Distribution: Chiefly east of the Cascades in Washington. British Columbia south to California, east to Colorado and South Dakota.
Habitat: Open, moderately dry areas from foothills to mid-elevations in the mountains.
ssp. luzuloides – silvery brown everlasting, woodrush pussytoes
Antennaria mediaalpine pussytoes, Rocky Mountain pussytoes
Distribution: Circumboreal, south at high elevations in the mountains to California and Arizona
Habitat: Uncommon in high mountain meadows
Antennaria microphyllasmall-leaf pussytoes
Distribution: Alaska to California, east to North Dakota and Arizona, from lower montane to sub-alpine.
Habitat: Moist, open areas, flood plains of streams, margins of alkali depressions.
Antennaria monocephalapygmy pussytoes
Antennaria parvifolialittle-leaf pussytoes
Distribution: Eastern base of the Rocky Mountains, extending westward rarely to eastern Washington and British Columbia.
Habitat: Foothills and dry open areas to moderate elevations.
Antennaria pulcherrima
ssp. pulcherrima – showy pussytoes
Antennaria racemosaslender everlasting, Hooker's pussytoes, raceme pussytoes
Distribution: Widely distributed throughout the forested and mountainous areas of Washington; British Columbia south to California, east to the northern Rocky Mountains.
Habitat: Open, modertely dry areas from low to mid-elevations in the mountains.
Antennaria rosearosy everlasting, rosy pussytoes
Distribution: Alaska to California, east to Quebec and New Mexico.
Habitat: Dry or moist ground, from near sea level to alpine.
ssp. arida – desert pussytoes
ssp. confinis – elegant pussytoes
ssp. pulvinata – pulvinate pussytoes
ssp. rosea – rosy everlasting, rosy pussytoes
Antennaria stenophyllanarrowleaved pussytoes
Distribution: East of the Cascades crest in Washington; Washington south to Nevada, east to Idaho.
Habitat: Shrub-steppe, dry meadows and open woods.
Antennaria umbrinellabrown everlasting, brown-bract pussytoes, umber pussytoes
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains.
Habitat: Uncommon in openings in the forest at moderate elevations.
Anthemis arvensiscorn chamomile, field chamomile
Distribution: Introduced in much of the United States; more common west of the Cascades in Washington
Habitat: Roadsides, disturbed areas
Anthemis cotulamayweed chamomile, stinking chamomile, dogfennel
Distribution: Introduced throughout the United States
Habitat: Weed of roadsides and disturbed area
Anthoxanthum aristatum
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia south to California; eastern half of North America.
Habitat: Meadows, grasslands, forest openings, and other disturbed, open areas at low to moderate elevations.
ssp. aristatum – small sweet vernal grass
Anthoxanthum hirtumhairy sweetgrass, vanillagrass
Distribution: Occurring in scattered locations across Washington; Alaska south to Washington, east across the northern half of North America to the Atlantic Coast.
Habitat: Wet meadows and marshes.
Anthoxanthum occidentaleCalifornia sweet grass, California sweetgrass
Anthoxanthum odoratumsweet vernalgrass
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska south to California, widely distributed throughout the eastern half of North America.
Habitat: Lawns, pastures and wasteland, usually where moist.
Anthriscus caucalisburr chervil
Distribution: Introduced occasionally in eastern United States, and from Washington to California.
Habitat: Moist, open places, usually in disturbed soil.
Anthriscus sylvestriswild chervil
Distribution: Escaped on both sides of the Cascades in Washington; British Columbia south to Oregon and Idaho; eastern North America and Greenland.
Habitat: Moist areas, usually on disturbed soil.
Anticlea elegansglaucous death camas
Distribution: In the Olympic Mountains of Washington and across the northern border east of the Cascacdes crest; Alaska to Oregon, south in the Rockies to New Mexico, east across Canada and the northern United States to Virginia.
Habitat: Meadow, open forests and rocky slopes, mid- to high elevations in the mountains.
Anticlea occidentalisbronze bells, mission bells, western featherbells
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east to Idaho and Montana.
Habitat: Wet cliffs, moist meadows and scree, mostly at mid- to high elevations, but down to near sea level in the Olympic Peninsula and the Columbia River Gorge.
Antirrhinum majusgarden snapdragon, greater snapdragon
Distribution: Occasionally escaped from cultivation in western Washington.
Habitat: Disturbed areas in urban settings.
Antirrhinum orontiumlesser snapdragon, weasel's snout
Distribution: Occasionally escaped from cultivation in western Washington.
Habitat: Disturbed areas in urban settings.
Apera interruptadense silky-bent
Distribution: Occurring chiefly east of the Cascades in Washington; British Columbia south to Oregon, east to Idaho and Montana.
Habitat: Dry wasteland and other disturbed areas in shrub-steppe and open coniferous forests.
Aphanes arvensiswestern lady's-mantle, field parsley-piert
Distribution: Southern British Columbia south east of the Cascades to California; common in eastern United States.
Habitat: Weed of open fields and wooded slopes.
Aphanes australissmall-fruited parsley-piert
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to Washington, also in southeastern U.S.
Habitat: Disturbed, open areas at low elevations.
Aphanes occidentalisparsley-piert
Aphyllon californicum
ssp. californicum – California broomrape
Aphyllon corymbosumflat-topped broomrape
Aphyllon fasciculatumclustered broom-rape, clustered broomrape
Aphyllon ludovicianumSuksdorf's broomrape
Aphyllon pinorumpinewoods broom-rape, pine broomrape
Aphyllon purpureumpurple broomrape
Aphyllon uniflorumnaked broom-rape, naked broomrape
Apium graveolens
Distribution: Introduced, occsionally escapes.
Habitat: Disturbed ground, usually where moist.
Apium prostratumprostrate marshwort
Apocynum androsaemifoliumspreading dogbane
Distribution: Throughout Washington and much of Canada and the United States
Habitat: Common on rather dry soil in open areas from low to fairly high elevations
Apocynum cannabinumIndian-hemp
Distribution: East of the Cascades in Washington; throughout much of North America.
Habitat: Uncommon in waste ground and lightly-cultivated areas, especially orchards.
Apocynum ×floribundum
Distribution: Both sides of the Cascades in Washington; widespread throughout North America.
Habitat: Dry, open areas at low elevations.
Apocynum sibiricum
Distribution: Occurring east of the Cascades crest in Washington; distributed across much of North America.
Habitat: Open areas from sagebrush desert to Pinus ponderosa forests at mid elevations.
var. salignum – clasping-leaved dogbane, Indian hemp
Aquilegia flavescensyellow columbine
Distribution: East of the Cascades, British Columbia to Kittitas County, Washington, east to Alberta, then south to Colorado; also, the Wallowa Mountains of Oregon
Habitat: Moist mountain meadows and talus to alpine slopes
Aquilegia formosared columbine, Sitka columbine
Distribution: Widely distributed throughout Washington; Alaska south to California, coastal and inland to Alberta and Wyoming.
Habitat: Open woods, lowlands to mid-elevations in the mountains.
var. formosa – red columbine, Sitka columbine, western columbine
Aquilegia vulgarisEuropean columbine
Distribution: Introduced as a garden flower, occasionally escaping.
Habitat: Disturbed soil near gardens.
Arabidopsis lyrata
ssp. kamchatica – lyreleaved cress, kamchatka rockcress, lyre-leaved rockcress, western rockcress
Arabidopsis thalianamouse-ear cress, thalecress
Distribution: Widely distributed througout Washington; widely distributed throughout North America.
Habitat: Disturbed areas, particularly near cities and towns.
Arabis crucisetosacrosshaired rockcress
Distribution: Occurring in the southeastern corner of Washington; Snake River canyon, Asotin County, Washington, east to west-central Idaho.
Habitat: Wet banks to moist soil or coniferous woods.
Arabis eschscholtzianahairy rockcress, Pacific coast rockcress
Distribution: Occurring on both sides of the Cascades in Washington; Alaska south to California, east to the northern Rocky Mountains.
Habitat: Open areas, often in waste places, from sea level to mid-elevations in the mountains.
Arabis furcataCascade rockcress, Columbia Gorge rockcress, fork-haired rockcress
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington south to Oregon.
Habitat: Open slopes, meadows, and ridgelines in alpine and subalpine areas.
Arabis nuttalliiNuttall's rockcress
Arabis olympicaOlympics rockcress
Aralia nudicauliswild sarsaparilla
Distribution: Occurring in northeastern region of Washington; Eastern British Columbia, east to the Atlantic Coast, and south in the mountains to Colorado.
Habitat: Moist, shaded soil.
Arbutus menziesiiPacific madrona, Pacific madrone
Distribution: West of the Cascades in Washington; British Columbia south to California.
Habitat: Chiefly in drier, often rocky, areas at low elevations
Arceuthobium americanumlodgepole pine dwarf-mistletoe
Distribution: Chiefly east of the Cascades crest in Washington; southern British Columbia south to California, east to Montana, Colorado and New Mexico.
Habitat: Parasitic on Pinus, usually on Pinus contorta.
Arceuthobium campylopodumfir dwarf-mistletoe, western dwarf-mistletoe, hemlock mistletoe
Distribution: In the Pacific Northwest on Pinus contorta and P. ponderosa (Compare range of these two species)
Habitat: Parasitic on Pinus contorta and P. ponderosa, sea level to mid-elevations in the mountains
Arceuthobium douglasiiDouglas-fir dwarf-mistletoe
Distribution: British Columbia to California, east to Montana and New Mexico.
Habitat: On the branches of Pseudotsuga menziesii.
Arceuthobium laricislarch dwarf-mistletoe
Arctium lappagreat burdock, greater burdock
Distribution: Known from a few scattered locations in Washington; widely distributed throughout much of North America except the central U.S.
Habitat: Disturbed areas including roadsides, wastelots, and forest openings.
Arctium minuscommon burdock, lesser burdock
Distribution: Introduced throughout the United States
Habitat: Weed of roadsides and disturbed area
Arctostaphylos columbianabristly manzanita
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia south to California.
Habitat: Moist, open woods.
Arctostaphylos ×mediamedium manzanita
Distribution: Chiefly on the east side of the Olympic Peninsula, Washington
Habitat: Low to moderate elevations
Arctostaphylos nevadensis
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington south to California, east to Nevada.
Habitat: Chiefly in the mountains at mid-elevations.
ssp. nevadensis – pinemat manzanita
Arctostaphylos patulagreen-leaf manzanita
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Montana and Colorado.
Habitat: Low elevations in the mountains.
Arctostaphylos uva-ursired bearberry, kinnikinnik
Distribution: Widely distributed throughout Washington; Alaska south to California and New Mexico, east to the Atlantic Coast; circumboreal.
Habitat: Coastal bluffs and prairies, rocky balds, dry subalpine meadows, and dry coniferous forest.
Arenaria paludicolamarsh sandwort
Arenaria serpyllifolia
Distribution: Widely distributed across Washington; introduced in most of North America.
Habitat: Weed in various habitats.
var. serpyllifolia – thyme-leaf sandwort
Aristida purpurea
Distribution: British Columbia and eastern Washington, east to the Dakotas, south to Oregon and Arizona.
Habitat: Desert plains and grasslands, into the foothills.
var. longiseta – red threeawn
Armeria maritima
Distribution: West of the Cascades in Washington, chiefly along the coast; Alaska south to California, also Newfoundland and Europe.
Habitat: Along beaches and coastal bluffs, occasionally inland.
ssp. californica – thrift
Armoracia rusticanahorseradish
Distribution: Occurring in scattered locations in eastern portion of Washington; British Columbia south to California, east across the U.S. and Canada to the Atlantic Coast.
Habitat: Disturbed areas including fields, roadsides and wastelots.
Arnica chamissonisleafy arnica, meadow arnica, narrowleaf arnica, silvery arnica, leafy leapordbane
Distribution: Occurring in the Cascades and northeastern corner of Washington; Alaska south to California, east across Canada and to the Rockies in the U.S.
Habitat: Meadows and wet places at moderate elevations.
Arnica cordifoliaheart leaf arnica, hear-leaf leopardbane
Distribution: Pacific Northwest, including southern British Columbia, and east into the Rocky Mountains
Habitat: Moderately dry, open forests from fairly low (where common) to sub-alpine
Arnica discoidearayless arnica, rayless leopardbane
Distribution: Cascades of Klickitat and Skamania counties in Washington; Washington south to California.
Habitat: Open forest at moderate elevations.
Arnica fulgenshillside arnica, orange arnica, shining leopardbane
Distribution: British Columbia to California, uncommon east to North Dakota; east of the Cascades in Washington and Oregon
Habitat: Open places from the foothills to moderate elevations in the mountains
Arnica gracilisslender arnica, slender leopardbane
Distribution: Occurring in mountainous areas throughout Washington; British Columbia south to California, east to Colorado and Utah.
Habitat: Rocky places, usually at rather high elevations in the mountains.
Arnica lanceolata
Distribution: Cascades Mountains to the coast in Washington; Alaska to California, east to western Montana.
Habitat: Streambanks and moist woods at moderate to mid-elevations in the mountains.
ssp. prima – clasping arnica, streambank arnica, streambank leopardbane
Arnica latifoliabroad leaved arnica, mountain arnica, daffodil leopardbane
Distribution: Both sides of the Cascades in Washington; Alaska south through Washington.
Habitat: Common in open forests and open, rocky areas at mid- to high elevations in the mountains.
Arnica longifolialongleaf arnica, seep spring arnica, spear-leaf leopardbane
Distribution: Southern Alberta south to Washington, Colorado and California.
Habitat: Rocky soil in seeps or springs, cliffs, or riverbanks, at moderate to high elevations in the mountains.
Arnica molliscordilleran arnica, hairy arnica, cordilleran leopardbane
Distribution: In the mountains from British Columbia to California, east to Alberta and Colorado
Habitat: Frequent in moist meadows at mid- to high elevations in the mountains
Arnica nevadensisNevada arnica, Sierra arnica, Sierran leopardbane
Distribution: Cascade and Olympic Mountains of Washington, south to California; rare in our range.
Habitat: Open, rocky slopes at high elevations in the mountains.
Arnica ovatasticky arnica, sticky leaf arnica
Distribution: Both sides of the Cascades in Washington; Alaska south to California, east to Montana and Utah.
Habitat: Rocky places at moderate to high elevations in the mountains.
Arnica parryiParry's arnica
Distribution: In the mountains from British Columbia to California, east to Alberta and Colorado
Habitat: Open woods and meadows, moderate to mid-elevations in the mountains
Arnica rydbergiiRydberg's arnica, subalpine arnica, subalpine leopardbane
Distribution: British Columbia south to northern California, east to Alberta and Colorado.
Habitat: Dry meadows and open slopes at high elevations in the mountains.
Arnica sororiabunch arnica, twin arnica, twin leopardbane
Distribution: Chiefly east of the Cascades, British Columbia to California, east to Wyoming.
Habitat: Open, often rather dry places, but usually vernally moist, in the foothills and at moderate elevations in the mountains.
Aronia melanocarpablack chokeberry
Arrhenatherum elatius
Distribution: Introduced more commonly west of the Cascades, British Columbia south to California, east to Idaho and Montana.
Habitat: Meadows and pastures.
var. bulbosum – bulbous oatgrass [Marsh]
var. elatius – bulbous oatgrass [Marsh]
Artemisia absinthiumabsinthe, oldman, wormwood
Distribution: Introduced in the northern half of the United States and southern Canada
Habitat: Weed of roadsides and waste places
Artemisia annuasweet Annie, sweet sagewort, annual wormwood
Distribution: Native of Eurasia, naturalized in eastern United States, rare in the Pacific Northwest.
Habitat: Fields and waste places.
Artemisia arbuscula
Distribution: East of the Cascades in Washington; Pacific Northwest, east into Montana
Habitat: Open, dry plains and hills at moderate to high elevations.
ssp. arbuscula – little sagebrush, low sagebrush
Artemisia biennisbiennial wormwood
Distribution: Native in the Pacific Northwest, but widely distributed elsewhere as a weed.
Habitat: Waste places and streambanks, especially in sandy soil.
Artemisia campestris
Distribution: Occurring on both sides of the Cascades crest in Washington; widely distributed throughout most of Washington.
Habitat: Open places, often in sandy soil.
var. caudata – northern woomwood
var. scouleriana – Pacific sagewort, Scouler's wormwood
var. wormskioldii – Columbia Islands sagewort, Wormskiold's wormwood sagewort
Artemisia cana
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Meadows and forest openings from valley bottoms to moderate elevations in the mountains.
Artemisia douglasianaDouglas mugwort, Douglas sagewort, Douglas wormwood
Distribution: Occurring in Washington chiefly east of the Cascades crest, but also on the west side; widely distributed throughout much of North America.
Habitat: Mostly along stream banks and river bottoms.
Artemisia dracunculusdragon sagewort, tarragon, dragon wormwood
Distribution: Occurring east of the Cascades crest in Washington; widely distributed throughout the central and western portions of North America.
Habitat: Shrub-steppe to dry, open areas at mid-elevations.
Artemisia frigidaprairie sagebrush, prairie sagewort
Distribution: Rocky Mountains and Great Plains states, occasionally in eastern Washington and British Columbia
Habitat: Dry, open plains and foothills
Artemisia furcatathree-forked mugwort, forked wormwood, three-forked wormwood
Distribution: Occurring in the Cascades and Olympic Mountains of Washington; Alaska south to Washington, east to Northwest Territories, Alberta, and Nunavut.
Habitat: Open, rocky ledges and talus slopes at high elevations in the mountains.
Artemisia ludoviciana
Distribution: Occurring on both sides of the Cascades in Washington; distributed widely throughout North America.
Habitat: Fairly dry areas from the foothills to high elevations in the mountains.
ssp. candicans – gray sagewort
ssp. incompta – intermediate sagewort, mountain wormwood
ssp. ludoviciana – western mugwort, Louisiana sagewort, silver wormwood
Artemisia michauxianaMichaux's mugwort, lemon sagewort, Michaux's wormwood
Distribution: British Columbia to California, east to Alberta and Wyoming.
Habitat: Rocky places in the mountains at rather high elevations.
Artemisia norvegica
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska south to California, east to the Rocky Mountains.
Habitat: Subalpine and alpine areas, typically where moist.
ssp. saxatilis – mountain sagewort
Artemisia rigidascabland sagebrush, stiff sagebrush
Distribution: Occurring east of the Cascades crest in Washington; Washington south to Oregon, east to Idaho and Montana.
Habitat: Dry, rocky places from the plains and foothills to moderate elevations in the mountains.
Artemisia spiciformissnowfield sagebrush, spiked sagebrush
Artemisia stellerianadusty miller, oldwoman, beach wormwood, Steller's wormwood
Distribution: Known from a few locations along the north coast in Washington; known only from Washington in western North America; central Canada and U.S. to the Atlantic Coast.
Habitat: Coastal dunes and beaches.
Artemisia suksdorfiicoastal mugwort, Suksdorf's sagewort, coastal wormwood
Distribution: Occurring west of the Cascades crest in Washington, British Columbia south to California.
Habitat: Bluffs and rocky or sandy beaches, less commonly in other low, open places.
Artemisia tilesiiAleutian mugwort, Cascade wormwood
Distribution: Occurring in the Olympic and Cascade Mountains of Washington; Alaska to Oregon, east to Montana and across Canada.
Habitat: Open rocky or gravelly, wet or dry sites, mostly at high elevations in the mountains, descending to sea level northward.
Artemisia tridentata
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Dry plains and hills up to timberline, but not in lithosol or alkaline soil.
ssp. tridentata – big sagebrush
ssp. vaseyana – mountain big sagebrush, Vasey sagebrush
ssp. wyomingensis – Wyoming sagebrush
Artemisia tripartita
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to Oregon, east to Idaho and Nevada.
Habitat: Sagebrush-steppe grasslands and desert.
ssp. tripartita – cutleaf sagebrush, threetip sagebrush
Artemisia vulgarismugwort, lobed wormwood
Distribution: Introduced from Europe, now established in most of eastern United States and adjacent Canada; uncommon in the Pacific Northwest.
Habitat: Waste areas and disturbed soil.
Arum italicumlarge cuckoo pint
Distribution: Limited number of locations in western Washington; south to California; scattered location in central and eastern U.S.
Habitat: Forest understory and disturbed locations near urbanized areas.
Aruncus dioicus
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska south to California.
Habitat: Moist woods, low to mid-elevations in the mountains.
var. acuminatus – Sylvan goatsbeard
Asarum caudatumwild ginger
Distribution: Widely distributed throughout Washington except in central lowlands; British Columbia south to Oregon, east to Idaho and Montana.
Habitat: Moist, shady woods at low to mid-elevations in the mountains.
Asclepias cryptoceraspallid milkweed
Distribution: Asotin County, Washington and Grant County, Oregon, to Payette County, Idaho, south to California and Colorado.
Habitat: Gravelly to heavy clay soil in the hills and lower mountains.
Asclepias fascicularisnarrow-leaf milkweed
Distribution: East of the Cascades in Washington; east to Idaho and Utah, reaching the coast in Oregon.
Habitat: Uncommon in shrub-steppe, usually along vernal stream beds.
Asclepias incarnataswamp milkweed
Distribution: Known from Okanogan County in Washington; Washington, also in Idaho, east across North America to Atlantic Coast.
Habitat: Riparian zone, including standing water
Asclepias speciosashowy milkweed
Distribution: Chiefly east of the Cascades in Washington; British Columbia east to Manitoba, south to Mexico.
Habitat: Open areas at low elevations in dry to moist, loamy to sandy soil
Asparagus officinalisasparagus
Distribution: Introduced throughout the United States
Habitat: Garden escape, often of roadsides.
Asperugo procumbenscatchweed, madwort
Distribution: Introduced in much of the northern part of the United States; common east of the Cascades in Washington and Oregon
Habitat: A weed of moist soil in fields, roadsides and other disturbed areas, mostly east of the Cascades.
Aspidotis densaOregon cliff brake, Indian's dream, podfern
Distribution: British Columbia to California, east to Idaho and Montana
Habitat: Cliff crevices and moist, rocky slopes, foothills to near timberline, often on serpentine
Asplenium trichomanes
Distribution: Throughout most of the United States; more common west of the Cascades in Washington and Oregon.
Habitat: Cliff crevices and talus slopes, generally where moist.
ssp. quadrivalens – maidenhair spleenwort
ssp. trichomanes – maidenhair spleenwort
Asplenium viridegreen spleenwort
Distribution: Both sides of the Cascades crest in Washington; Alaska to California, east across northern North America to New England and the Canadian Maritimes; circumboreal.
Habitat: Cliff crevices, especially on limestone, often near or above timberline.
Astragalus agrestiscock's-head, field milk vetch, purple milk vetch
Distribution: Occurring east of the Cascades crest in Washington; widely distributed in the western, central, and northeastern regions of North America.
Habitat: Moist spots in sagebrush plains, and mountain meadows to alpine slopes.
Astragalus alpinus
Distribution: Circumpolar, arctic to sub-alpine regions, south to Okanogan County, WA, the Wallowa Mountains of Oregon, and the Rocky Mountains of Montana and Idaho.
Habitat: Open, often rocky areas.
var. alpinus – alpine milk-vetch
Astragalus arrectushanging pod milk-vetch, Palouse milk-vetch
Astragalus arthuriiArthur's milk-vetch, waha milk-vetch
Distribution: Occurring in the southeastern corner of Washington; northern foothills of the Wallowa and Blue Mountains in Oregon and Nez Perce County, Idaho.
Habitat: Dry, grassy and rocky meadows, on basalt.
Astragalus asotinensis
Distribution: Endemic to Snake River Canyon of WA and ID.
Habitat: Shrub-steppe at low to moderate elevations.
Astragalus australis
Distribution: Endemic to Olympic Mountains of Washington.
Habitat: Ridge tops and talus slopes.
var. cottonii – Cotton's milk-vetch, Cotton's milkvetch
Astragalus beckwithii
var. weiserensis – beckwith's milk-vetch
Astragalus canadensis
var. brevidens – Canada milk-vetch
var. canadensis – Canada milk-vetch
var. mortonii – Morton's Canadian milkvetch
Astragalus caricinusbuckwheat milk-vetch
Distribution: Occurring east of the Cascades crest in the south-central part of Washington; Washington south to Oregon, east to Idaho.
Habitat: Grasslands, dry and sandy slopes in shrub-steppe habitat.
Astragalus cicerchickpea milk-vetch
Distribution: Scattered locations throughout Washington; distributed throughout much of western North America, and central and eastern Canada.
Habitat: Disturbed areas, often where moist or wet.
Astragalus collinus
Distribution: East of the Cascades, southern British Columbia south to Oregon, east to west-central Idaho along the Snake and Clearwater Rivers.
Habitat: Basaltic grasslands and sagebrush deserts.
var. collinus – hillside milk-vetch
Astragalus columbianusColumbian milk-vetch
Distribution: Occurring east of the Cascades crest in the south-central part of Washington; endemic to Washington;
Habitat: Dry, open areas in shrub-steppe.
Astragalus conjunctus
Distribution: Wasco County, Oregon, to the Blue Mountains, south along the Malheur River to the Steens, and east into Idaho
Habitat: Drier areas, moderate and higher elevations
var. rickardii – stiff milk-vetch
Astragalus cusickii
Distribution: Known only from Asotin County in Washington; Washington south to northeastern Oregon, east to Custer County, Idaho.
Habitat: Sagebrush plains to grassy or rocky slopes, often on talus.
var. cusickii – Cusick's milk vetch
Astragalus diaphanustransparent milk-vetch, John Day milk vetch
Distribution: Along the Columbia River from the mouth of the John Day river in Wasco County, Oregon, to Klickitat County, Washington.
Habitat: Gravel bars, alluvial slopes, and in thin gravelly soil overlying basaltic rock.
Astragalus falcatusRussian-sickle
Astragalus filipesbasalt milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to northeast California, east to Nevada and Idaho.
Habitat: Sagebrush plains and lower foothills.
Astragalus geyeri
Distribution: Southeast Oregon to California and Nevada, east through the Snake River drainage of Idaho.
Habitat: Sandy desert, especially on dunes.
var. geyeri – Geyer's milk-vetch
Astragalus hoodianusHood River milk-vetch
Distribution: Columbia River Gorge, Wasco and Hood River Counties in Oregon, Klickitat County in Washington
Habitat: Dry, open areas
Astragalus howelliiHowell's milk-vetch
Astragalus inflexusbent milk-vetch, hairy milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; Washington south to Oregon, east to Idaho and Montana.
Habitat: Dry hillsides in shrub-steppe habitat.
Astragalus kentrophyta
var. douglasii – thistle milk vetch
Astragalus laxmannii
var. robustior – standing milk-vetch
Astragalus leibergiiLeiberg's milk-vetch
Distribution: Endemic to Douglas, Kittitas and Chelan counties of central Washington.
Habitat: Dry hillsides and plains, commonly in sagebrush scabland on basalt.
Astragalus lentiginosus
Distribution: East of the Cascades crest in Washington; British Columbia south to California, east to Montana and Texas.
Habitat: Open areas, desert flats to subalpine slopes.
var. lentiginosus – freckled milk-vetch, specklepod milk-vetch
Astragalus lyalliiLyall's milk-vetch
Distribution: Endemic to Washington from Kittitas and Douglas counties south to Benton, east to Grant and Adams counties.
Habitat: Sagebrush and desert areas, especially on sand dunes.
Astragalus microcystislesser-bladder milk-vetch
Distribution: Northeast Washington and adjacent British Columbia, across Idaho to Montana and Wyoming
Habitat: Prairies and foothills to Ponderosa pine forests
Astragalus misellus
Distribution: Occurring east of the Cascades crest in Washington; Washington south to Oregon.
Habitat: Dry, open areas in shrub-steppe.
var. pauper – pauper milk-vetch
Astragalus miser
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia and northern Washington east to Alberta and South Dakota, and south in the Rockies to Colorado.
Habitat: Moist meadowlands to open, dry ridges, and in grasslands and foothills to above timberline in the mountains.
var. miser – weedy milk-vetch
var. serotinus – weedy milk-vetch
Astragalus pulsiferae
Distribution: Mt. Adams and Klickitat County, Washington, and the ascades and northern Sierra Nevada of California; not reported from Oregon.
Habitat: Sandy and gravelly flats in sagebrush and open pine forests on basalt.
var. pulsiferae – ames milk-vetch
var. suksdorfii – ames milk-vetch
Astragalus purshii
Distribution: East of the Cascades in Washington; British Columbia to California, east to the Dakotas and New Mexico.
Habitat: Prairies and sagebrush deserts, foothills and lower mountains.
var. glareosus – woolly-pod milk-vetch
var. purshii – woolly-pod milk-vetch
var. tinctus – woolly-pod milk-vetch
Astragalus reventiformisYakima milk-vetch
Distribution: East of the Cascades in Washington; Washington south to Sherman County in Oregon.
Habitat: Shrub-steppe to low, dry open forests.
Astragalus reventuslongleaf milk-vetch, Blue Mt.milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; Washington south to northeastern Oregon.
Habitat: Forest openings at low to moderate elevations.
Astragalus ripariusPiper's milk-vetch
Distribution: Along the Snake River from the Clearwater to the Tucannon River, Whitman and Columbia Counties, WA, and in Nex Perce County, ID.
Habitat: Dry bluffs and canyon banks.
Astragalus robbinsii
Distribution: Alaska and British Columbia south on the east side of the Cascades to Okanogan County, Washington,east to Alberta and south in the Rockies to Colorado.
Habitat: Stream banks and alpine slopes.
var. minor – Robbin's milk-vetch
Astragalus sclerocarpusstalked-pod milk-vetch, woody-pod milk-vetch
Distribution: Along the Okanogan and Columbia Rivers from north of Kettle Falls to The Dalles
Habitat: Dunes and sandy barrens, low elevation
Astragalus sheldoniiSheldon's milk-vetch
Distribution: Occurring in the southeastern part of Washington; Washington south to Oregon, east to Idaho.
Habitat: Shrub-steppe and Ponderosa pine forest openings.
Astragalus sinuatuswhited milk-vetch
Distribution: Along Colockum Creek, south of Wenatchee in Chelan County, Washington.
Habitat: Among sagebrush on rocky hillsides.
Astragalus spaldingiiSpalding's milk-vetch
Distribution: East of the Cascades, central Washington to northeast Oregon, east to western Idaho.
Habitat: Sagebrush and grasslands in the foothills and valleys.
Astragalus speirocarpuscurve-pod milk-vetch, medic milk-vetch, spiral-pod milk-vetch
Distribution: Endemic to Washington from Kittitas County east to Grant County, south Klickitat County.
Habitat: Sagebrush desert.
Astragalus succumbenscrouching milk-vetch, sprawling milk-vetch
Distribution: Occurring east of the Cascades crest in Washington from Kittitas and Grant counties south; Washington south to Umatilla and Gilliam Counties, Oregon.
Habitat: Sagebrush deserts, sandy barrens and lower foothills.
Astragalus tenelluspulse milkvetch
Astragalus tweedyiTweedy's milk-vetch
Distribution: Yakima County, Washington, south to north-central Oregon near the olumbia dn lower Deschutes Rivers
Habitat: Sagebrush plains and foothills
Astragalus whitneyi
Distribution: Occurring east of the Cascades in Washington; Washington south to California, east to Idaho and Nevada.
Habitat: High, open, rocky ridges and slopes, often in serpentine.
var. sonneanus – balloon milk-vetch
Athyrium distentifolium
Distribution: Occurring on both sides of the Cascades crest in Washington.
Habitat: Open, rocky slopes and along streams at mid- to high elevations in the mountains.
ssp. americanum – American alpine lady fern
Athyrium filix-femina
Distribution: Circumboreal; throughout the Pacific Northwest
Habitat: Common in moist woods and meadows, low to mid-elevations
var. cyclosorum – lady fern, northwestern lady fern
Athysanus pusillussandweed
Distribution: Both sides of the Cascades in Washington; British Columbia south to California, east to Idaho.
Habitat: Dry, open, often grassy places.
Atriplex argentea
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Great Plains.
Habitat: Sagebrush flats and washes, tolerant of alkaline soils.
var. argentea – silver saltbush, silverscale
Atriplex canescens
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to the Great Plains.
Habitat: Saline areas in the prairies.
var. canescens – hoary saltbush
Atriplex dioicathickleaf orach, saline saltbush
Atriplex gardneri
Distribution: Occurring at low elevations in central Washington; Alberta south to California, east to the Great Plains.
Habitat: Sagebrush-steppe desert.
var. falcata – moundscale, gardner's saltbush, sickle saltbush, saltsage
Atriplex gmelinii
Distribution: Occurring along the coast in Washington; Alaska south to California.
Habitat: On coastal beaches, strands, and rocky outcroppings near the high tide in saline soil.
var. gmelinii – Gmelin's saltbush orach
Atriplex heterospermaorach, Russian atriplex orach
Distribution: Primarily east of the Cascades crest in Washington; occurring in scattered locations throughout North America.
Habitat: Riparian zones and adjacent fields; tolerant of alkaline.
Atriplex hortensisgarden orache, French spinach
Distribution: Occurring east of the Cascades crest in Washington; Alaska south to California, east to the Great Plains and in scattered locations in eastern North America.
Habitat: Disturbed areas, often where seasonally moist.
Atriplex littoralisgrassleaf orache, narrow-leaved orache
Atriplex longipesbare-stemmed goosefoot; nude orach, long-stalked orache, Baltic saltbush
Atriplex oblongifoliaoblongleaf orache
Atriplex patulahalberdleaf orache, spear oracle
Distribution: Occurring on both sides of the Cascades crest in Washington; occurring in scattered locations throughout North America.
Habitat: Coastal and inland, saline or alkaline soil.
Atriplex prostratafat hen, hastate orache, thin-leaf orache
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington south to California, in scattered location across Canada and the U.S. to the Atlantic Coast.
Habitat: Along the coast in saline soils, beaches, and strands; inland in alkaline soils.
Atriplex roseared orach, tumbling orach
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains; scattered locations in central and eastern U.S.
Habitat: Weedy species of irrigated land and roadsides.
Atriplex semibaccataAustralian saltbush, berry saltbush, creeping saltbush
Distribution: Occasionally introduced in eastern and central WA; scattered localities primarily in southwestern US.
Habitat: Disturbed areas from dry to moist, tolerant of alkaline soils.
Atriplex truncatawedge orache, wedgeleaf orache, wedgescale orache
Atropa bella-donnabelladonna, deadly nightshade
Avena barbatabarbed oat
Distribution: Introduced and common in southwest United States; occasional in Washington and western Oregon.
Habitat: Roadsides and waste land.
Avena fatuawild oat
Distribution: Common introduction in most of western North America.
Habitat: A weed in grain fields, roadsides and waste ground.
Avena sativaoat
Distribution: Commonly cultivated throught the United States and Canada, occasionally escaping but usually not persisting.
Habitat: Roadsides and field margins.
Azolla filiculoidesduckweed fern, large mosquito fern
Distribution: Occurring on both sides of the Cascades in Washington; British Columbia south to California, east to Arizona.
Habitat: Ponds, backwaters, slow-moving streams
Azolla mexicanaMexican waterfern fern, mosquito fern
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east to New Mexico and Colorado; disjunct populations in central U.S.
Habitat: Ponds and backwaters, mostly at low elevations.