Vascular Plants

Includes all flowering plants, conifers, ferns and fern-allies.


Browse by scientific name:

A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z
Scientific names beginning with A:
Abies amabilisPacific silver fir
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California.
Habitat: Mostly at 1000-4000 feet elevation in the mountains.
Origin: Native
Growth Duration: Perennial
Abies grandisgrand fir
Distribution: Occurring on both sides of the Cascades crest in Washington; Vancouver Island, British Columbia to California, east to Idaho and Montana.
Habitat: Coniferous forests, from sea level to mid-elevations in the mountains.
Origin: Native
Cones: May-June
Growth Duration: Perennial
Abies lasiocarpaalpine fir, subalpine fir
Distribution: Occurring in mountainous regions throughout Washington; Alaska to southern Oregon, east to the Rocky Mountains.
Habitat: Subalpine to alpine slopes, where commonly in krumholtz form.
Origin: Native
Cones: June-July
Growth Duration: Perennial
ssp. bifolia – Rocky Mountain subalpine fir
ssp. lasiocarpa – subalpine fir
Abies proceranoble fir
Distribution: Occurring chiefly west of the Cascades crest in Washington; Washington to California.
Habitat: Deep forests where there is sufficient moisture, moderate to fairly high elevations.
Origin: Native
Growth Duration: Perennial
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.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Abronia melliferahoney-scented sandverbena, 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.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Abronia umbellatapink sandverbena
Distribution: Occurring west of the Cascades crest along the outer coast in Washington; British Columbia to Baja California.
Habitat: Coastal sandy beaches and adjacent dunes.
Origin: Native
Flowers: May-September
Growth Duration: Perennial
var. acutalata – sand verbena
var. breviflora – sand verbena
Abutilon theophrastivelvetleaf
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, wastelots, and other disturbed open places.
Origin: Introduced from Eurasia
Flowers: July-August
Growth Duration: Annual
Acer campestrefield maple, hedge maple
Distribution: Occurring west of the Cascades crest in Washington; Washington to California, also in scattered locations in eastern North America.
Habitat: Fields, forest edges, and other disturbed areas where escaped from cultivation
Origin: Introduced from Eurasia
Flowers: April-May
Acer circinatumvine maple
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to northern California.
Habitat: Moist woods from sea level to mid-elevations in the mountains.
Origin: Native
Flowers: March-June
Growth Duration: Perennial
Acer glabrumRocky Mountain maple
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains and Great Plains.
Habitat: Moist woods from sea level to mid-elevations in the mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
var. douglasii – Douglas maple
Acer macrophyllumbig-leaf maple
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to southern California.
Habitat: Moist woods from sea level to middle elevations in the mountains.
Origin: Native
Flowers: March-June
Growth Duration: Perennial
Acer negundobox elder, box elder maple
Distribution: Occurring chiefly east of the Cascades in Washington; widely distributed throughout much of North America.
Habitat: Occasionally escapes from cultivation, chiefly in disturbed areas or riparian zones.
Origin: Introduced from eastern North America, escaped from cultivation
Flowers: April-June
Growth Duration: Perennial
Acer platanoidesNorway maple
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington east to Idaho, also widespread in eastern North America.
Habitat: Forest edge, riparian zones, fields, and other disturbed areas where escaped from cultivation.
Origin: Introduced from Europe
Flowers: April-May
Growth Duration: Perennial
Acer pseudoplatanussycamore maple
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Oregon, east to Montana, also in eastern North America.
Habitat: Forest edge, fields, and other disturbed areas where escaped from cultivation.
Origin: Introduced from Europe
Flowers: April-May
Growth Duration: Perennial
Acer saccharinumsilver maple
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Idaho and Montana, also in central and eastern North America where native.
Habitat: Riparian corridors, moist bottomlands, and other areas near water, often disturbed.
Origin: Introduced from central and eastern North America
Flowers: March-April
Growth Duration: Perennial
Achillea millefoliummilfoil, yarrow
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Atlantic Coast; circumboreal
Habitat: Common in open, dry to somewhat moist areas from low to high elevations; tolerant of disturbance.
Origin: Both native and introduced populations
Flowers: February-October
Growth Duration: Perennial
Achillea ptarmicapearl yarrow
Distribution: Reported from Washington but no specimens seen; Alaska to Oregon, east in scattered locations across North America to the Atlantic Coast.
Habitat: Roadsides, wastelots, and other disturbed open areas where occasinally escaping from cultivation.
Origin: Introduced from Eurasia
Flowers: May-August
Growth Duration: Annual, Perennial
Achlys californicadeer's-foot
Distribution: On both sides of the Cascades and in the Olympic Mountains in Washington; British Columbia to California.
Habitat: Moist areas in deep woods to open parks.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Achlys triphylladeerfoot, vanillaleaf
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California.
Habitat: Moist areas in deep woods to forest openings.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
ssp. triphylla – deerfoot, vanillaleaf
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.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
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.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Achnatherum lemmoniiLemmon's needlegrass
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east to the Rocky Mountains.
Habitat: Grassy balds, prairies, sagebrush grasslands, and ponderosa pine forest, from the lowlands to middle elevations in the mountains.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
ssp. lemmonii – Lemmon's needlegrass
Achnatherum nelsonii
Origin: Native
Growth Duration: Perennial
ssp. dorei – Nelson's needlegrass
ssp. nelsonii – Nelson's needlegrass
Achnatherum nevadenseNevada needlegrass
Origin: Native
Achnatherum occidentale
Origin: Native
Growth Duration: Perennial
ssp. californicum – California needlegrass
Achnatherum richardsoniiRichardson's rice grass
Origin: Native
Flowers: June - July
Growth Duration: Perennial
Achnatherum thurberianumThurber's rice grass
Origin: Native
Flowers: Late May - June
Growth Duration: Perennial
Acmispon americanusAmerican bird's-foot trefoil
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Rocky Mountains, south to Mexico.
Habitat: Chiefly in sandy to rocky, exposed or wooded areas, more common at low elevations
Origin: Native
Flowers: April-September
Growth Duration: Annual
var. americanus – American bird's-foot trefoil
Acmispon denticulatusriverbar bird's-foot-trefoil
Distribution: Occurring on both sides of the Cascades in Washington; southern British Columbia to California, disjunct in southern Idaho and southwestern Utah.
Habitat: Sandy to rocky soil in open areas at low to moderate elevations.
Origin: Native
Flowers: April-June
Growth Duration: Annual
Acmispon nevadensisNevada bird's-foot trefoil, Nevada deervetch
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.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
var. nevadensis – Nevada deervetch
Acmispon parviflorussmall-flowered bird's-foot trefoil
Distribution: Occurring chiefly west of the Cascades crest and east in the Columbia River Gorge in Washington; British Columbia to California.
Habitat: Open slopes and sandy flats, seashore into the mountains.
Origin: Native
Flowers: April-September
Growth Duration: Annual
Aconitum columbianumColumbian monkshood
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains.
Habitat: Moist woods and meadows, moderate to subalpine elevations.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
ssp. columbianum – Columbian monkshood
Aconogonon davisiaeNewberry's fleeceflower, Davis' knotweed, Davis's knotweed
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.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Aconogonon phytolaccifoliumalpine fleeceflower
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.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
var. phytolaccifolium – 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.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Acorus calamussweet flag
Origin: Introduced from Eurasia
Growth Duration: Perennial
Actaea elatatall bugbane
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to Oregon.
Habitat: Moist, shady woods at low elevations.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
var. elata – tall bugbane
Actaea laciniatacut-leaved bugbane, Mt. Hood bugbane
Distribution: Occurring west of the Cascades crest in southwestern Washington; southwestern Washington to adjacent northwestern Oregon.
Habitat: Moist woods at middle elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Actaea rubrabaneberry
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Moist woods and streambanks from low elevations to middle elevations in the mountains.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Adelinia grandisAdeline's hound's-tongue, Pacific hound's-tongue, grand hound
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; Washington to California.
Habitat: Forest openings and meadows at low to moderate elevations.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Adenocaulon bicolorpathfinder, trailplant
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east the northern Rocky Mountains, northern Great Plains, and Great Lakes region.
Habitat: Moist, shady woods at low to middle elevations.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Adiantum aleuticummaidenhair fern, northern maidenhair fern
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east sporadically to the Rocky Mountains, also in the Great Lakes region and northeastern North America.
Habitat: Moist woods and streambanks, from low to middle elevations in the mountains.
Origin: Native
Growth Duration: Perennial
var. aleuticum – Aleutian maidenhair fern, western maidenhair fern
Adonis aestivalissummer pheasant's-eye
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Montana, Idaho, and Utah.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Europe
Flowers: May-June
Growth Duration: Annual
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.
Origin: Introduced from southern Europe
Flowers: June - July
Growth Duration: Annual
Aegopodium podagrariabishop's goutweed
Distribution: Occurring in scattered locations west of the Cascades crest in the Puget Trough in Washington; southern British Columbia to Oregon, also in eastern North America.
Habitat: Disturbed forest understory and edge, where often dumped as garden waste.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Perennial
Aesculus hippocastanumhorse-chestnut
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Oregon, also in central and eastern North America.
Habitat: Disturbed forested areas, particularly in urban and suburban areas where the species is planted as a street tree.
Origin: Introduced from Europe
Flowers: May-June
Growth Duration: Perennial
Agastache occidentaliswestern giant-hyssop
Distribution: Occurring east of the Cascades crest in Washington; Washington to Oregon.
Habitat: Dry, open, often rocky slopes at low to moderate elevations.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Agastache urticifolianettle-leaf giant-hyssop
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Dry open slopes and draws, foothills to mid-elevations in the mountains
Origin: Native
Flowers: May-August
Growth Duration: Perennial
var. urticifolia – nettle-leaf giant-hyssop
Ageratina occidentaliswestern boneset, western snakeroot
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Montana, Utah, and Nevada.
Habitat: Rocky places at various altitudes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Agoseris ×agrestisfield agoseris
Origin: Native
Agoseris apargioidesseaside agoseris
Distribution: Occurring west of the Cascades crest in Washington along the outer coast. Washington to California.
Habitat: Coastal dunes and beach heads.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
var. maritima – seaside agoseris
Agoseris aurantiacaorange agoseris
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, Great Plains, and Quebec.
Habitat: Meadows and forest openings at from middle elevations to the alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
var. aurantiaca – orange agoseris, slender agoseris
var. carnea – pink agoseris
Agoseris ×elatatall agoseris, tall goat-chicory
Distribution: Occurring on both sides of the Cascades crest in Washington; south-central British Columbia to California.
Habitat: Meadows and open woods, from the valleys to middle elevations in the mountains.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Agoseris glaucapale agoseris, short-beaked agoseris
Distribution: Occurring chiefly east of the Cascades crest in Washington; Yukon Territory to California, east to the Rocky Mountains, northern Great Plains, and Great Lakes region.
Habitat: Open forests and open areas, from low to high elevations in the mountains.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
var. dasycephala – pale goat-chicory
var. glauca – pale agoseris, short beaked agoseris
Agoseris grandifloralarge-flowered agoseris
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Montana, Idaho and Nevada.
Habitat: Prairies, balds, meadows, and forest openings, often where seasonally dry, from low to middle elevations in the mountains.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
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 to California, east to Idaho, Montana, Utah, and Arizona.
Habitat: Dry, open areas at low to mid-elevations.
Origin: Native
Flowers: April-July
Growth Duration: Annual
Agoseris monticolamountain agoseris, Sierra Nevada agoseris
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Nevada.
Habitat: Mesic meadows in the subalpine and alpine, often in soils of volcanic origin.
Origin: Native
Flowers: July-August
Growth Duration: Perennial
Agoseris retrorsaspear leaved agoseris, spear leaf goat-chicory
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Nevada, Utah, and Arizona.
Habitat: Sagebrush desert, grassy slopes, and ponderosa pine forest openings at low to middle elevations.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Agrimonia gryposepalatall hairy agrimony, tall hairy grooveburr
Distribution: Reported from Washington but currently no specimens exist; British Columbia to California, east to the Rocky Mountains.
Habitat: Edges, openings, draws, thickets, and open forest.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
×Agropogon lutosusperennial beardgrass
Origin: Introduced
Agropyron cristatumcrested wheatgrass
Distribution: Introduced for forage purposes in many areas of western United States, becoming widely established.
Habitat: Dry, open areas.
Origin: Introduced
Flowers: June - August
Growth Duration: Perennial
Agropyron fragileSiberian wheatgrass
Origin: Introduced
Agrostemma githagocommon corncockle
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Roadsides and wasteland.
Origin: Introduced from Europe
Flowers: June-July
Growth Duration: Annual
var. githago – common corncockle
Agrostis caninavelvet bentgrass
Origin: Introduced from Eurasia
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.
Origin: Introduced
Flowers: June-August
Growth Duration: Perennial
Agrostis castellanaHighland bent, dryland browntop
Origin: Introduced
Agrostis densifloraCalifornia bentgrass
Distribution: Occurring west of the Cascades crest in western Washington along the outer coast; coastal Washington to California.
Habitat: Coastal bluffs.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
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.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
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.
Origin: Introduced
Flowers: June-September
Growth Duration: Perennial
Agrostis idahoensisIdaho bent
Origin: Native
Flowers: July - August
Growth Duration: Perennial
Agrostis mertensiiMerten's bentgrass, northern bentgrass
Origin: Native
Flowers: July - August
Growth Duration: Perennial
Agrostis microphyllasmall-leaf bent
Origin: Native
Flowers: May - June
Growth Duration: Annual
Agrostis ×murbeckii
Origin: Introduced
Agrostis oregonensisOregon bent
Origin: Native
Flowers: July - August
Growth Duration: Perennial
Agrostis pallensseashore bent
Distribution: Near the coast, Grays Harbor County, Washington south to San Francisco, California.
Habitat: Coastal sand dunes and immediately adjacent woods.
Origin: Native
Flowers: Late June - August
Growth Duration: Perennial
Agrostis scabrarough bent
Origin: Native
Flowers: June - August
Growth Duration: Perennial
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.
Origin: Introduced?
Flowers: June-September
Growth Duration: Perennial
Agrostis variabilisalpine bent
Origin: Native
Flowers: Late July - September
Growth Duration: Perennial
Ailanthus altissimatree-of-heaven
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across most of North America to the Atlantic Coast.
Habitat: Escaped ornamental in roadsides, waste areas, along railroad tracks, and other open, disturbed areas.
Origin: Introduced from China
Flowers: May-July
Growth Duration: Perennial
Aira caryophylleasilver hairgrass
Distribution: Occurring west of the Cascades crest in Washington and east in the Columbia River Gorge; British Columbia to California, east to Idaho and Wyoming, also in the southeastern U.S. and northeastern North America.
Habitat: Balds, prairies, meadows, forest openings, roadsides, wastelots, and other open areas at low to middle elevations.
Origin: Introduced Eurasia and North Africa
Flowers: May-August
Growth Duration: Annual
var. caryophyllea – silver hairgrass
Aira elegansdelicate hairgrass
Origin: Introduced
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.
Origin: Introduced
Flowers: April-September
Growth Duration: Annual
Ajuga reptanscarpet bugle
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Oregon, east in scattered locations in Idaho and Montana; widespread in central and eastern North America.
Habitat: Disturbed ground, often in forest understory.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial
Alhagi maurorumcamelthorn
Distribution: Occurring east of the Cascades crest in Washington; Washington and California, scattered eastward to the Rocky Mountains and Texas.
Habitat: Disturbed areas in arid lands at low to moderate elevations.
Origin: Introduced from Asia
Flowers: June-August
Growth Duration: Perennial
Aliciella leptomeriaGreat Basin gilia, sand gily-flower
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.
Origin: Native
Flowers: April-June
Growth Duration: Annual
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.
Origin: Native
Flowers: April-June
Growth Duration: Annual
Alisma gramineumgrass-leaved water-plantain, narrow-leaf water-plantain
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Minnesota and Wisconsin.
Habitat: Marshy areas, often in standing water.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Alisma plantago-aquaticaEuropean water plantain
Distribution: Currently only known from King County in Washington; Alaska, where native, to British Columbia, where also introduced.
Habitat: Marshy areas, sometimes largely submerged.
Origin: Introduced from Eurasia and Alaska
Flowers: June-September
Growth Duration: Perennial
Alisma trivialenorthern water plantain
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across much of North America to the Atlantic Coast.
Habitat: Streams, lakes, ponds, wet ditches, wetlands, and cattle ponds.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Alliaria petiolatagarlic mustard
Distribution: Occurring west of the Cascades crest in lowland western Washington; British Columbia to Oregon, also in Utah, widespread from central Great Plains to eastern North America.
Habitat: Disturbed forest understory, often where moist, at low elevations.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Annual, Biennial
Allium acuminatumtaper-tip onion
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east to Wyoming.
Habitat: Balds, grasslands, rocky outcroppings, dry slopes, and other open areas from low to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium amplectensnarrow-leaf onion
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California.
Habitat: Dry slopes and open meadows at low to middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium campanulatumrosy Sierra onion
Distribution: Occurring east of the Cascades crest where known from Yakima County in Washington; Washington to California, east to Nevada.
Habitat: Dry soils at medium to high elevations.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Allium cernuumnodding onion
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia 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.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium columbianumColumbia onion
Distribution: Occurring east of the Cascades crest in far eastern Washington; Washington to Idaho and Montana.
Habitat: Seasonally wet soils on rock outcrops, wet meadows.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium constrictumGrand Coulee onion
Distribution: Occurring east of the Cascades crest in Grant and Douglas counties in Washington.
Habitat: Shallow, vernally-moist soils in low, open areas.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium crenulatumscalloped onion
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon.
Habitat: Forest openings and mountain meadows, moderate to high elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium dictuonBlue Mountain onion
Distribution: Occurring east of the Cascades crest in Washington, where endemic to Columbia County.
Habitat: Open, fairly dry, rocky areas at low to middle elevations.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Allium douglasiiDouglas' onion
Distribution: Occurring east of the Cascades crest in Washington; central and eastern Washington to northeastern Oregon.
Habitat: Open, vernally-moist areas at low to moderate elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
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.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium geyeriGeyer's onion
Distribution: Occurring east of the Cascades crest in Washington; southern Vancouver Island to Arizona, east to the Rocky Mountains and northern Great Plains.
Habitat: Low meadows and along streams.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
var. geyeri – Geyer's onion
var. tenerum – Rydberg's onion
Allium macrumrock onion
Distribution: Occurring east of the Cascades crest in Washington; central Washington to southern Oregon and southwestern Idaho.
Habitat: Lithosol and barren, gravelly soils in the shrub-steppe.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Allium neviiNevius's garlic, Nevius's onion
Distribution: Occurring east of the Cascades crest in central Washington; Chelan County, Washington to Wasco County, Oregon
Habitat: Vernally wet meadows and rocky soils at low to middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
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.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
var. sativum – garlic
Allium schoenoprasumchives
Distribution: Occurring east of the Cascades crest in Washington; Alaska to Oregon and Nevada, east to the Rocky Mountains, further east across Canada to the Great Lakes region and eastern North America.
Habitat: Wet meadows, rocky or gravelly streambanks and lake shores
Origin: Both native and introduced populations
Flowers: April - August
Growth Duration: Perennial
Allium scilloidesfragile onion, scilla-like onion
Distribution: Occurring east of the Cascades crest, where endemic in Washington from Douglas to Klickitat counties.
Habitat: Scablands and dry, barren, gravelly soils.
Origin: Native
Flowers: March-April
Growth Duration: Perennial
Allium textiletextile onion, white wild onion
Distribution: Reported to occur east of the Cascades crest in southeastern Washington, but no specimens have been seen; Alberta to northeastern Nevada, east to Utah and New Mexico.
Habitat: Open areas in plains and low hills.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Allium tolmieiTolmie's onion
Distribution: Occurring east of the Cascades crest in southeastern Washington; southeastern Washington to adjacent western to Idaho, south to northeastern California.
Habitat: Rocky, gravelly or clayey soils, generally with sparse cover.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
var. tolmiei – Tolmie's onion
Allium validumPacific onion, swamp onion
Distribution: Occurring near Mount Rainier in Washington, where likely introduced; southern British Columbia to California, east to Idaho and northern Nevada.
Origin: Introduced?
Flowers: June-August
Growth Duration: Perennial
Allium vinealewild chives, crow garlic, wild garlic
Distribution: Occurring chiefly west of the Cascades crest in Washington; southwestern British Columbia to California; also in eastern North America.
Habitat: Disturbed areas.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial
Allotropa virgatacandystick, sugarstick
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Montana, Idaho, and Nevada.
Habitat: Deep humus of coniferous forests at low to middle elevations.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Alnus glutinosaBlack alder, European alder
Distribution: Occurring west of the Cascades crest in King County, where escaping from a wetland restoration planting. Great Lakes region east to the Atlantic Coast.
Habitat: Wetlands at low elevation.
Origin: Introduced from Europe
Flowers: March-May
Growth Duration: Perennial
Alnus incanamountain alder
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, and eastern North America,
Habitat: Moist places, streamsides, and avalanche chutes from low to middle elevations.
Origin: Native
Flowers: March-May
Growth Duration: Perennial
ssp. tenuifolia – mountain alder
Alnus rhombifoliawhite alder
Distribution: Chiefly east of the Cascades crest in Washington; Washington to California and Nevada, east to Idaho.
Habitat: Near streams at low elevations.
Origin: Native
Flowers: January-April
Growth Duration: Perennial
Alnus rubrared alder
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, disjunct to the east in northern Idaho.
Habitat: Moist areas at low elevations.
Origin: Native
Flowers: March-April
Growth Duration: Perennial
Alnus viridisgreen alder, mountain alder
Distribution: Widely distributed throughout the mountainous areas on both sides of the Cascades crest in Washington; Alaska to California, east across the northern half of North America to the Atlantic Coast.
Habitat: Moist areas, low to high elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
ssp. fruticosa – Siberian alder
ssp. sinuata – mountain alder, Sitka alder
Alopecurus aequalislittle foxtail, short-awn foxtail
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Shores, riverbanks, vernal pools, sloughs, wet meadows, and seeps, often submersed.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Alopecurus arundinaceuscreeping meadow-foxtail
Origin: Introduced
Growth Duration: Perennial
Alopecurus carolinianustufted meadow-foxtail
Origin: Introduced
Flowers: May - July
Growth Duration: Annual
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.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Alopecurus myosuroidesslender meadow-foxtail
Distribution: Introduced in many parts of North America; occasional in Washington and Oregon.
Habitat: Wet places.
Origin: Introduced
Flowers: June - August
Growth Duration: Annual
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.
Origin: Introduced from Europe
Flowers: June - July
Growth Duration: Perennial
Alopecurus saccatusPacific meadow-foxtail
Origin: Native
Flowers: May - June
Growth Duration: Annual
Alyssum alyssoidessmall alyssum, pale madwort
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Meadows, forest openings, sagebrush flats, roadsides, fields, and disturbed open areas at low to middle elevations.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Annual, Biennial
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.
Origin: Introduced from Eurasia
Flowers: May-June
Growth Duration: Annual
Amaranthus albuswhite pigweed, tumbleweed
Distribution: Occurring east of the Cascades crest in Washington; widely distributed throughout much of North America.
Habitat: Dry, disturbed areas.
Origin: Introduced from tropical America
Flowers: June-September
Growth Duration: Annual
Amaranthus blitoidesmatweed, prostrate pigweed
Distribution: Introduced in the Pacific Northwest; more common east of the Cascades
Habitat: Dry, disturbed areas
Origin: Introduced from central United States
Flowers: June - September
Growth Duration: Annual
Amaranthus blitumlivid amaranth, pale amaranth
Origin: Introduced from the tropics
Growth Duration: Annual
Amaranthus californicusCalifornia amaranth
Origin: Native
Flowers: July - October
Growth Duration: Annual
Amaranthus caudatus
Origin: Introduced
Amaranthus cruentusblood amaranth, caterpillar amaranth, purple amaranth
Origin: Probably introduced from cultivation in Central America
Growth Duration: Annual
Amaranthus deflexusArgentina amaranth
Origin: Introduced
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.
Origin: Introduced from riparian zones in eastern North America
Flowers: July - September
Growth Duration: Annual
Amaranthus hypochondriacus
Origin: Introduced
Amaranthus powelliigreen amaranth, Powell's amaranth
Distribution: Introduced in much of the United States; common in the Pacific Northwest
Habitat: Disturbed areas
Origin: Introduced from the southwestern United States and Mexico
Flowers: July - October
Growth Duration: Annual
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.
Origin: Introduced from eastern and central North America
Flowers: July-October
Growth Duration: Annual
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.
Origin: Introduced from the Great Plains of the central United States
Flowers: April-June
Growth Duration: Annual
Amauropelta nevadensisNevada marsh fern, Sierra marsh fern
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to central Cascades in Washington; also in eastern Asia.
Habitat: Stream banks, moist forest, and springs, lowland to midmontane.
Origin: Native
Growth Duration: Perennial
Ambrosia acanthicarpaflat spine bur-ragweed, annual bursage, bur ragweed
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to the Great Plains.
Habitat: Sandy soils, dunes, and other well-drained soils in open areas at low to middle elevations, often locally common.
Origin: Native
Flowers: July-October
Growth Duration: Annual
Ambrosia artemisiifoliaannual ragweed, common ragweed
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, pastures, wastelots, and other dry, disturbed, open areas at low elevations.
Origin: Introduced from eastern North America
Flowers: August-October
Growth Duration: Annual
Ambrosia chamissonissilver beachweed, beach bur, cutleaf beach bur, silver bur-ragweed
Distribution: Occurring along the marine coastline beaches in Washington; British Columbia, south along the coast, to California.
Habitat: Common on sandy beaches above high tide level.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Ambrosia psilostachyaperennial ragweed, western ragweed
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, wastelots, and other disturbed open areas.
Origin: Native
Flowers: July-October
Growth Duration: Perennial
Ambrosia trifidagiant ragweed
Distribution: Occurring chiefly east of the Cascades crest; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, wastelots, and other disturbed sites, often where moist.
Origin: Native
Flowers: July-October
Growth Duration: Annual
Amelanchier alnifoliasaskatoon, serviceberry
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains and Great Plains.
Habitat: Open woods, canyons and hillsides, sea level to subalpine.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Amelanchier utahensisUtah serviceberry
Distribution: Occurring east of the Cascades crest in Washington; Washington to Baja California, east to the Rocky Mountains and Texas.
Habitat: Rimrock, valleys, gullies and hillsides, from sagebrush desert to mid-elevations in the mountains.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Ammannia coccineavalley redstem
Distribution: Occurring west of the Cascades crest, where known only from a restoration site in King County; California east along Mexican border to central and eastern U.S.
Habitat: Restored wetland.
Origin: Introduced from southwestern U.S.
Flowers: June-August
Growth Duration: Perennial
Ammannia robustawestern ammania, grand redstem
Distribution: Occurring east of the Cascades crest in Washington chiefly along the Columbia River; British Columbia to California, east to the Great Lakes region and midwestern U.S.
Habitat: Wet places, often where alkaline.
Origin: Native
Flowers: May-June
Growth Duration: Annual
Ammophila arenariaEuropean beachgrass
Distribution: Introduced along the Pacific coast from southeast Washington the California.
Habitat: Sandy beaches and dunes.
Origin: Introduced
Flowers: June-August
ssp. arenaria – European beach grass
Ammophila breviligulataAmerican beachgrass
Origin: Introduced
ssp. breviligulata – American beachgrass
Amorpha fruticosafalse indigo-bush
Distribution: Occurring chiefly east of the Cascades crest and along the Columbia River in Washington; Washington to California, east across much of North America, including eastern Canada.
Habitat: Disturbed areas, roadsides, wastelots, and often along streams, rivers and other riparian corridors.
Origin: Introduced from eastern North America, where native
Flowers: May-July
Growth Duration: Perennial
Amphiscirpus nevadensisNevada bulrush
Origin: Native
Amsinckia intermediafireweed fiddleneck, rancher's fiddleneck
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Baja California, Mexico, east to Idaho, Utah, Arizona, and west Texas.
Habitat: Balds, meadows, prairies, roadsides, and other open areas at low to middle elevations.
Origin: Native
Flowers: April-May
Growth Duration: Annual
Amsinckia lycopsoidesbugloss fiddleneck, tarweed fiddleneck
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Great Plains, also in eastern North America.
Habitat: Roadsides, fields, meadows, grassy slopes, ponderosa pine forest openings, and other open areas from sagebrush desert into the mountains, often associated with some type of disturbance .
Origin: Native
Flowers: April-July
Growth Duration: Annual
Amsinckia menziesiiharvest fiddleneck, rigid fiddleneck, rancher's fireweed
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to California.
Habitat: Open, dry foothills.
Origin: Native
Flowers: April-July
Growth Duration: Annual
Amsinckia retrorsaharvest fiddleneck, rigid fiddleneck
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Idaho and Utah.
Habitat: Relatively dry and open areas at low to moderate elevations.
Origin: Native
Flowers: April-June
Growth Duration: Annual
Amsinckia spectabilisseaside amsinckia, seaside fiddleneck
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California.
Habitat: Coastal dunes or sandy bluffs.
Origin: Native
Flowers: May-July
Growth Duration: Annual
var. spectabilis – seaside amsinckia, seaside fiddleneck
Amsinckia tessellatabristly amsinckia, bristly fiddleneck, tessellate fiddleneck
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Idaho, south to New Mexico.
Habitat: Roadsides and dry, open slopes and flats, often in disturbed soil.
Origin: Native
Flowers: April-June
Growth Duration: Annual
var. tessellata – bristly amsinckia, bristly fiddleneck, tessellate fiddleneck
Anaphalis margaritaceapearly everlasting
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast except for extreme southeastern U.S.
Habitat: Dry to somewhat moist open areas, from low elevations to the subalpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Anchusa azureaItalian alkanet, Italian bugloss
Distribution: Occurring in scattered localities on both sides of the Cascades crest in Washington; British Columbia to California, scattered localities east to the Atlantic Coast.
Habitat: Disturbed soil.
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Perennial
var. azurea – Italian alkanet, Italian bugloss
Anchusa officinaliscommon alkanet, common bugloss
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east to Rocky Mountains and northern Great Plains, also from the Great Lakes region to northeastern North America.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed, open areas at low elevations.
Origin: Introduced from Mediterranean region
Flowers: May-July
Growth Duration: Biennial, Perennial
Andromeda polifoliabog rosemary
Distribution: Reported to occur in northern Washington but no specimens seen; Alaska to Idaho, east across Canada, in the Great Lakes region, and in the northeastern U.S.
Habitat: Sphagnum bogs and other acidic wetlands.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
var. polifolia – bog rosemary
Androsace filiformisslender-stem rock-jasmine
Distribution: Occurring east of the Cascades crest in the Columbia River Gorge in Washington; south-central Washington to adjacent Oregon, east to Montana, Utah, and Colorado; disjunct in California.
Habitat: Damp to wet meadows, shores, riparian flats and thickets.
Origin: Native
Flowers: June-July
Growth Duration: Annual
Androsace septentrionalisnorthern fairy-candelabra, rock jasmine, pygmyflower
Distribution: Occurring east of the Cascades crest in north-central Washington; Alaska to California, east to the Great Plains, Great Lakes regiona, and eastern Canada.
Habitat: Alpine meadows.
Origin: Native
Flowers: May-August
Growth Duration: Annual
Anemone deltoideathree-leaf anemone, Columbian windflower
Distribution: Occurring west of the Cascades crest and east in the Columbia River Gorge in Washington; Washington to California.
Habitat: Dry to moist woodlands at low to middle elevations.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Anemone drummondiiDrummond's anemone, Drummond's windflower
Distribution: Occurring in the Olympic and Cascade Mountains in Washington; Alaska to California, east to Montana and Wyoming.
Habitat: Subalpine to alpine meadows.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
var. drummondii – Drummond's anemone, Drummond's windflower
Anemone lyalliilittle mountain anemone, Lyall's anemone, Lyall's windflower
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California.
Habitat: Low elevation prairies to subalpine ridges.
Origin: Native
Flowers: March-July
Growth Duration: Perennial
Anemone multifidacliff anemone, Pacific anemone
Distribution: Occurring on both sides of the Cascades crest and in the Olympic Mountains in Washington; Alaska to California, east to the northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: From forest openings in the foothills to alpine meadows.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
var. multifida – cliff anemone, Pacific anemone, Pacific windflower
var. saxicola – hirsute anemone, hirsute windflower
Anemone occidentalismountain pasqueflower, western pasqueflower
Distribution: Occurring in the Olympic and Cascade mountains in Washington; British Columbia to California, east to Alberta, Montana, Idaho, and the Wallowa Mountains of Oregon.
Habitat: Open slopes and meadows from middle elevations to the alpine.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Anemone oreganaOregon anemone, Oregon windflower
Distribution: Occurring in forested areas on both sides of the Cascades crest in Washington; Washington to northern California.
Habitat: Moist, open woods, low to mid-elevations in the mountains, also in marshes and bogs along the coast.
Origin: Native
Flowers: March-June
Growth Duration: Perennial
var. felix – Oregon anemone, western wood anemone
var. oregana – Oregon anemone, western wood anemone
Anemone parvifloranorthern anemone, small-flowered anemone, northern windflower
Distribution: Occurring on both sides of the Cascades crest in the North Cascades in Washington; Alaska to northern Washington, east to Montana and Wyoming, in scattered locations in Utah and Colorado, and also east across northern Canada to the Atlantic Coast.
Habitat: Mountain meadows and subalpine stream banks.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Anemone patenspasqueflower, prairie-crocus
Distribution: Occurring east of the Cascades crest in the Wenatchee Mountains in Washington, where disjunct; Alaska, south in the Rocky Mountains to New Mexico, east to the northern Great Plains and the Great Lakes region, disjunct in the Wenatchee Mountains in Washington.
Habitat: Prairies to mountain slopes, mostly on well-drained soil.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
var. multifida – cliff anemone
Anemone piperiPiper's anemone, Piper's windflower
Distribution: Occurring east of the Cascades crest in Washington in the far eastern part of the state; Washington to northeast Oregon east to Idaho and western Montana.
Habitat: Shady woods at moderate elevations in the mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Anethum graveolensdill
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east across much of North America to the Atlantic Coast.
Habitat: Roadsides, fields, wastelots, and other disturbed open areas.
Origin: Introduced from Asia
Flowers: May-August
Growth Duration: Annual
Angelica argutaLyall's angelica, sharp-tooth angelica
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia 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.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Angelica canbyiCanby's angelica
Distribution: Occurring chiefly east of the Cascades crest in Washington, though disjunct on the Olympic Peninsula; northern Washington to central and northeastern Oregon.
Habitat: Meadows and forest openings, generally where moist, from low to middle elevations in the mountains.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Angelica genuflexakneeling angelica
Distribution: Occurring chiefly west of the Cascades crest and east in the Columbia River Gorge in Washington; Alaska to California, east in British Columbia to the Selkirk Mountains.
Habitat: Stream banks, wet meadows and other moist places, from low to middle elevations in the mountains.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Angelica hendersoniiHenderson's angelica, woolly angelica
Distribution: Occurring on the outer coast in Washington; northwestern Washington to California.
Habitat: Coastal bluffs and sand dunes.
Origin: Native
Flowers: July-August
Growth Duration: Perennial
Angelica lucidaseacoast angelica, sea-watch
Distribution: Occurring west of the Cascades crest in Washington in the coastal counties; Alaska to California, also in eastern North America; Far East Russia.
Habitat: Coastal bluffs, beaches, and estuaries.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Anisocarpus madioideswoodland tarplant, woodland tarweed
Distribution: Occurring west of the Cascades crest in lowland western Washington; Southern British Columbia to southern California.
Habitat: Open woods and woodland edge, and thickets.
Origin: Native
Flowers: May-July
Growth Duration: Biennial, Perennial
Antennaria alpinaalpine pussytoes
Distribution: Occurring in the North Cascades Mountains in Washington; Alaska to Washington, Montana, and Wyoming, east across Canada; circumboreal.
Habitat: Alpine meadows.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Antennaria anaphaloidestall pussytoes
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia, including southern Vancouver Island, to Oregon, east to Sasketchewan, Montana, Colorado, and Nevada.
Habitat: Grassy hillsides, open woodlands, and ponderosa pine forest openings from the foothills to middle elevations in the mountains.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Antennaria corymbosaflat topped pussytoes, meadow pussytoes
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to the Rocky Mountains.
Habitat: Streamsides, willow thickets and moist meadows in subalpine and alpine areas.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Antennaria dimorphacushion pussytoes, low pussytoes
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and Nebraska.
Habitat: Dry, open places in sagebrush desert to ponderosa pine forest openings, often on lithosol.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Antennaria flagellarisstoloniferous pussytoes, whip pussytoes
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Idaho, Wyoming, South Dakota, and Nevada.
Habitat: Sagebrush desert to dry, open areas at middle elevations, often in lithosol.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Antennaria geyeriGeyer's pussytoes, pinewoods pussytoes
Distribution: Occurring east of the Cascades crest in southern Washington; southern Washington to California, east to Nevada.
Habitat: Rocky slopes with ash, sand, or pumice soils, lithosols, and open forest.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Antennaria howelliiHowell's pussytoes
Distribution: Occurring on both sides of the Cascades crest in Washington; Yukon Territory to California, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Rocky or sandy slopes, dry to moist grasslands, and forest openings at low to middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
ssp. howellii – Howell's pussytoes
ssp. neodioica – northern pussytoes
Antennaria lanatawoolly pussytoes
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Wyoming, and Utah.
Habitat: Dry or moist subalpine to alpine meadows, rocky slopes, and ridges.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Antennaria luzuloidessilvery-brown pussytoes, woodrush pussytoes
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and South Dakota.
Habitat: Sagebrush grasslands at low elevations to dry, rocky slopes at middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
ssp. luzuloides – silvery brown pussytoes, woodrush pussytoes
Antennaria mediaalpine pussytoes, Rocky Mountain pussytoes
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains; circumboreal
Habitat: On rocky slopes and ridges, and in talus and pumice, from subalpine to alpine meadows.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Antennaria microphyllalittle-leaf pussytoes, rosy pussytoes, white pussytoes
Distribution: Occurring on both sides of the Cascades crest in Washington, but more common east of the crest; Alaska to California, east to the Rocky Mountains and northern Great Plains, Great Lakes region, and eastern Canada.
Habitat: Dry to moist habitats, including meadows, ponderosa pine forest openings, rocky slopes, and floodplains from the lowlands to the alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Antennaria monocephalapygmy pussytoes, single-headed pussytoes
Distribution: Reported from the North Cascades in Washington; Alaska to British Columbia, east to Alberta, Montana, and Wyoming; also in the Russian Far East.
Habitat: Alpine meadows, ridges, and rocky outcroppings.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Antennaria parvifolialittle-leaf pussytoes, Nuttall's pussytoes
Distribution: Occurring east of the Cascades crest in northeastern Washington; British Columbia to Oregon, east to the Rocky Mountains, Great Plains, and Great Lakes region.
Habitat: Meadows, open forest, gravelly slopes, and sandy flats from the lowlands middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Antennaria pulcherrimashowy pussytoes
Distribution: Occurring east of the Cascades crest in Washington; Alaska to Washington, east to the Rocky Mountains, east across Canada to the Atlantic Coast.
Habitat: Streams, wet thickets and meadows, and peatlands from middle elevations to the alpine.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Antennaria racemosaHooker's pussytoes, raceme pussytoes
Distribution: Widely distributed in mountainous areas on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, and Wyoming.
Habitat: Dry to damp rocky slopes, forest openings, and ledges from low to elevations to the alpine.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Antennaria stenophyllanarrowleaved pussytoes
Distribution: Occurring east of the Cascades crest in Washington; Washington to Nevada, east to central Idaho.
Habitat: Rocky slopes, flats, lithosol areas, and dry grasslands in sagebrush desert.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Antennaria umbrinellabrown-bract pussytoes, umber pussytoes
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Saskatchewan, Montana, Wyoming, and Colorado.
Habitat: Forest openings at middle elevations to subalpine meadows.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Anthemis arvensiscorn chamomile, field chamomile
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, east to the northern Great Plains in the U.S, widespread from the midwestern U.S. to eastern North America.
Habitat: Roadsides, fields, wastelots, and other disturbed open areas generally at low elevations.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Annual
Anthemis cotulamayweed chamomile, stinking chamomile, dogfennel
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed areas generally at low elevations.
Origin: Introduced from Europe
Flowers: May-October
Growth Duration: Annual
Anthoxanthum aristatumannual vernalgrass
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.
Origin: Introduced
Flowers: May-July
Growth Duration: Annual
ssp. aristatum – small sweet vernal grass
Anthoxanthum odoratumsweet vernalgrass
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, southern Great Plains, and eastern North America.
Habitat: Roadsides, fields, meadows, prairies, balds, lawns, and other disturbed open areas at low elevations.
Origin: Introduced from Europe
Flowers: April-July
Growth Duration: Perennial
Anthriscus caucalisburr chervil
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across much of the United States and parts of Canada to the Atlantic Coast.
Habitat: Roadsides, forest edges, wastelots, and other disturbed areas where often seasonally moist.
Origin: Introduced from Eurasia
Flowers: April-July
Growth Duration: Annual
Anthriscus sylvestriswild chervil
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon, east to Idaho, also in eastern North America and Greenland.
Habitat: Roadsides, fields, forest edge, wastelots, and other disturbed areas where seasonally moist.
Origin: Introduced from Eurasia
Flowers: May-August
Growth Duration: Annual
Anticlea elegansglaucous death camas
Distribution: Occurring in the Olympic Mountains and Cascades Range in Washington; Alaska to Oregon and Nevada, east to the Rocky Mountains and northern Great Plains.
Habitat: Meadow, open forests and rocky slopes from middle elevations to the alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
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.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Antirrhinum majusgarden snapdragon, greater snapdragon
Distribution: Occasionally escaped from cultivation in western Washington.
Habitat: Disturbed areas in urban settings.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Annual
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.
Origin: Introduced
Flowers: May-July
Growth Duration: Annual
Apera spica-ventisilky windgrass
Origin: Introduced
Aphanes arvensiswestern lady's-mantle, field parsley-piert
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; southern British Columbia to California, reported in Idaho, also along Atlantic Coast in the U.S.
Habitat: Ledges, often limy, sandy shores, hot springs, and other disturbed open ground at low elevations.
Origin: Introduced from Eurasia and northern Africa
Flowers: April-May
Growth Duration: Annual
Aphanes australissmall-fruited parsley-piert
Distribution: Occurring west of the Cascades crest in Washington; southwestern British Columbia to northwestern Oregon, also in southeastern U.S.
Habitat: Openings, shores, lawns, and other disturbed areas at low elevations.
Origin: Introduced from Europe
Flowers: March-May
Growth Duration: Perennial
Aphanes occidentaliswestern parsley-piert
Distribution: Occurring west of the Cascades crest in lowland western Washington and east in the Columbia River Gorge; southern British Columbia to California.
Habitat: Vernally damp grasslands, balds, fields, ledges, rocky slopes, open forest, shores, and beaches at low elevations.
Origin: Native
Flowers: April-June
Growth Duration: Annual
Aphyllon californicumCalifornia broomrape
Distribution: Occurring west of the Cascades crest and east in the Columbia River Gorge in Washington; southwestern British Columbia to Baja California, also east of the Cascades crest in Oregon.
Habitat: Coastal and sub-coastal, or in meadows inland, parasitic on Asteraceae but not on Artemisia tridentata.
Origin: Native
Flowers: April-June
Growth Duration: Annual, Perennial
ssp. californicum – California broomrape
ssp. grayanum – Gray's California broomrape
Aphyllon corymbosumflat-topped broomrape
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and the Canadian Great Plains.
Habitat: Sagebrush desert areas, parasitic mainly on Artemisia tridentata.
Origin: Native
Flowers: May-July
Growth Duration: Annual, Perennial
ssp. corymbosum – flat-topped broomrape
ssp. mutabile – flat-topped broomrape
Aphyllon fasciculatumclustered broomrape
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to the Great Plains and the Great Lakes region.
Habitat: Dry, open places, valleys to montane, parasitic exclusively on Artemisia.
Origin: Native
Flowers: May-July
Growth Duration: Annual
Aphyllon franciscanumclustered broomrape
Distribution: Occurring on both sides of the Cascades crest in Washington; southwestern British Columbia to Baja California, east to the Rocky Mountains and Texas.
Habitat: Open areas from low to middle elevations. Parasitic on Eriogonum, Eriophyllum lanatum, and Phacelia, also other taxa outside of Washington, but never Artemisia.
Origin: Native
Flowers: April-August
Growth Duration: Perennial
Aphyllon ludovicianumLouisiana broomrape, Suksdorf's broomrape
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon, east to the Rocky Mountains and Great Plains of Canada and the U.S.
Habitat: Dry, open, often sandy areas, parasitic on Artemisia, Chrysopsis, and other woody Asteraceae.
Origin: Native
Flowers: May-July
Growth Duration: Annual
Aphyllon pinorumpine broomrape, pinewoods broomrape
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to California, east to northern Idaho, Nevada and New Mexico.
Habitat: Montane coniferous forest, parasitic on Holodiscus.
Origin: Native
Flowers: June-August
Growth Duration: Annual
Aphyllon purpureum
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Alberta and the Rocky Mountains.
Habitat: From lowland to montane, often where open and seasonally moist, parasitic mainly on Asteraceae, Saxifragaceae, and Sedum.
Origin: Native
Flowers: April-August
Growth Duration: Annual
Apium graveolenscelery
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; Washington to California, east to Idaho, Utah, and Nevada, east across the southern U.S. to eastern North America.
Habitat: Disturbed ground, usually where moist, where escaped from nearby cultivation.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial
Apocynum androsaemifoliumflytrap dogbane, spreading dogbane
Distribution: Occurring on both sides of the Cascades crest in Washington, but more common east of the crest; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Common in forest openings, thickets, hillsides, roadsides, meadows and other open areas with dry soil, from low elevations to nearly subalpine areas.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Apocynum cannabinumclasping-leaved dogbane, common dogbane, hemp dogbane
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Stream banks, moist hillsides and forest openings, fields, and wastelots at low to middle elevations.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Apocynum ×floribundumwestern dogbane
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Dry, open areas, gen in valleys and at lower elevations in the mountains.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Aquilegia flavescensyellow columbine
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon, east to the Rocky Mountains.
Habitat: Moist mountain meadows and talus to alpine slopes
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Aquilegia formosared columbine, Sitka columbine
Distribution: Widely distributed on both sides of the Cascades crest throughout Washington; Alaska to California, coastal and inland to Alberta and Wyoming.
Habitat: Open woods, from the lowlands to moderate elevations in the mountains.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
var. formosa – red Columbine, Sitka Columbine, western Columbine
Aquilegia vulgarisEuropean Columbine
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to Oregon, and other scattered areas in North America.
Habitat: Roadsides, wastelots, and other disturbed areas where escaping from cultivation.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Perennial
Arabidopsis kamchaticakamchatka rockcress, lyre-leaved rockcress, western rockcress
Distribution: Occurring west of the Cascades crest in northwestern Washington; Alaska to Washington, east to Northwest Territory and Sasketchewan.
Habitat: Subalpine and alpine scree and talus slopes.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Arabidopsis thalianamouse-ear cress, thalecress
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across most of North America.
Habitat: Disturbed areas, particularly near cities and towns.
Origin: Introduced from Eurasia
Flowers: March-May
Growth Duration: Annual
Arabis alpina
Origin: Introduced
Arabis caucasicamountain rockcress
Distribution: Known only from San Juan County in Washington; Yukon Territory to northwestern Washington.
Habitat: Open, disturbed areas at low elevation, often near where cultivated.
Origin: Introduced
Flowers: May-June
Growth Duration: Perennial
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.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Arabis eschscholtzianahairy rockcress, Pacific coast rockcress
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the northern Rocky Mountains.
Habitat: Open areas, often in waste places, from sea level to mid-elevations in the mountains.
Origin: Native
Flowers: April-July
Growth Duration: Annual, Biennial, Perennial
Arabis furcataCascade rockcress, Columbia Gorge rockcress, fork-haired rockcress
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to Oregon.
Habitat: Open slopes, meadows, and ridgelines in alpine and subalpine areas, and exposed areas in the Columbia River Gorge.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Arabis nuttalliiNuttall's rockcress
Distribution: Occurring east of the Cascades crest in Washington; eastern British Columbia to eastern Washington, east to Alberta, Montana, Wyoming, and Utah.
Habitat: Moist flats, often sheltered by shrubs, from the foothills to middle elevations in the mountains.
Origin: Native
Flowers: April-August
Growth Duration: Perennial
Arabis olympicaOlympics rockcress
Distribution: Occurring west of the Cascades crest in Washington, where endemic to the Olympic Mountains.
Habitat: Talus slopes and subalpine meadows.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Aralia elataJapanese Angelica
Habitat: Disturbed areas.
Origin: Naturalizing from horticultural introduction.
Flowers: Flowers late summer.
Aralia nudicauliswild sarsaparilla
Distribution: Occurring east of the Cascades crest in northeastern Washington; Yukon Territory to northeastern Washington, east to and south in Rocky Mountains, east to eastern North America.
Habitat: Moist, shaded soil.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Arbutus menziesiiPacific madrona, Pacific madrone
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to California.
Habitat: Chiefly in drier, often rocky areas at low elevations.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Arbutus unedostrawberry tree
Distribution: Occurring west of the Cascades crest in Washington; currently known as escaped from cultivation in Washington.
Habitat: Disturbed, open to partially sunny areas in and around urban areas, where escaped from cultivation.
Origin: Introduced
Flowers: April-September
Growth Duration: Perennial
Arceuthobium abietinumwhite fir dwarf mistletoe
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to California, east to Utah and Arizona.
Habitat: Primarily on Abies grandis and A. concolor.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Arceuthobium americanumlodgepole pine dwarf mistletoe
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east to the Rocky Mountains.
Habitat: Parasitic on Pinus, usually on Pinus contorta.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Arceuthobium campylopodumwestern dwarf mistletoe
Distribution: Occurring east of the Cascades crest in Washington; Washington to Baja California, east to Idaho.
Habitat: Parasitic on Pinus contorta and P. ponderosa, sea level to mid-elevations in the mountains.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Arceuthobium douglasiiDouglas-fir dwarf-mistletoe
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: On the branches of Pseudotsuga menziesii.
Origin: Native
Flowers: May - June
Growth Duration: Perennial
Arceuthobium laricislarch dwarf-mistletoe
Origin: Native
Growth Duration: Perennial
Arceuthobium tsugensehemlock dwarf mistletoe
Origin: Native
Growth Duration: Perennial
ssp. tsugense – hemlock mistletoe
Arcteranthis cooleyaeCooley's buttercup
Distribution: Occurring west of the Cascades crest in Washington; Alaska to Washington.
Habitat: Damp slopes and rocky crevices at high elevations, blossoming as snow recedes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arctium lappagreat burdock, greater burdock
Distribution: Known from a few scattered locations in Washington; British Columbia to California, in Montana, east from California to Colorado and Arizona, also across Canadian Great Plains to Great Lakes region and northeastern North America.
Habitat: Roadsides, ditches, forest openings and edge, wastelots, and other disturbed areas generally at low elevations.
Origin: Introduced from Eurasia
Flowers: August-October
Growth Duration: Biennial, Perennial
Arctium minuscommon burdock, lesser burdock
Distribution: Occurring on both sides of the Cascades crest in Washington; British to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, meadows, wastelots, and other disturbed open areas at low to middle elevations.
Origin: Introduced
Flowers: July-October
Growth Duration: Biennial
Arctostaphylos columbianabristly manzanita
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to California.
Habitat: Dry forest openings and rocky slopes, mostly at low elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Arctostaphylos ×mediamedium manzanita
Distribution: Occurring west of the Cascades crest in Washington, chiefly on the east side of the Olympic Peninsula. Washington to Oregon.
Habitat: Rocky balds and forest openings from low to moderate elevations.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Arctostaphylos nevadensispinemat manzanita
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to California, east to Nevada.
Habitat: Dry forest edge and openings from middle elevations in the mountains to the subalpine.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
ssp. nevadensis – pinemat manzanita
Arctostaphylos patulagreen-leaf manzanita
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Montana and Colorado.
Habitat: Low elevations in the mountains.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Arctostaphylos uva-ursired bearberry, kinnikinnick
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California east to the Rocky Mountains, also further east across the northern U.S. and Canada to the Atlantic Coast; circumboreal.
Habitat: Coastal bluffs and prairies, rocky balds, dry subalpine meadows, and dry coniferous forest openings.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Arenaria paludicolamarsh sandwort
Distribution: Presumed extirpated from Washington; historically west of the Cascades crest along the coast. California to Central America.
Habitat: Swampy places, mostly along coast.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Arenaria serpyllifoliathyme-leaf sandwort
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Dry to moist, barren to wooded places.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Annual
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.
Origin: Native
Flowers: June - July
Growth Duration: Annual, Perennial
var. longiseta – red threeawn
Armeria arenariaJersey thrift
Distribution: Occurring west of the Cascades crest in Washington; not known from elsewhere in North America.
Habitat: Roadsides, fields, ditches, and other disturbed open areas at low elevations.
Origin: Introduced from Europe
Flowers: April-July
Growth Duration: Perennial
Armeria maritimasea-pink, thrift
Distribution: Occurring west of the Cascades crest in Washington, chiefly in the coastal counties; Alaska to California, east across Canada to northeastern North America; Greenland and Europe.
Habitat: Along beaches, coastal bluffs and balds, occasionally inland in prairies.
Origin: Native
Flowers: March-July
Growth Duration: Perennial
ssp. californica – sea-pink, thrift
ssp. maritima – sea-pink, thrift
Armoracia rusticanahorseradish
Distribution: Occurring in scattered locations east of the Cascades crest in Washington; Alaska to California, east across the U.S. and Canada to the Atlantic Coast.
Habitat: Disturbed areas including fields, roadsides and wastelots.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Perennial
Arnica chamissonisleafy arnica, meadow arnica, narrowleaf arnica, silvery arnica, leafy leapordbane
Distribution: Occurring both sides of the Cascades, including the northeastern corner of Washington; Alaska to California, east to the Rocky Mountains, east across Canada to the Atlantic Coast.
Habitat: Meadows and wet places from middle elevations to the subalpine.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Arnica cordifoliaheart-leaf arnica, heart-leaf leopardbane
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, and the Great Lakes region.
Habitat: Light forest understory, openings, and edge, from low elevations to the subalpine.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Arnica discoidearayless arnica, rayless leopardbane
Distribution: Occurring in the Cascades Mountains of Klickitat and Skamania counties in Washington; Washington to California, east to Nevada.
Habitat: Forest openings from middle elevations to the subalpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica fulgenshillside arnica, orange arnica, shining leopardbane
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Meadows and open slopes from the foothills to middle elevations in the mountains
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Arnica gracilisslender arnica, slender leopardbane
Distribution: Occurring on both sides of the Cascades crest in the mountainous areas in Washington; British Columbia to Oregon, east to Alberta, Montana, Wyoming, and Utah.
Habitat: Dry, rocky slopes and meadows, from the subalpine to alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica lanceolataclasping arnica, stream bank arnica
Distribution: Occurring on both sides of the Cascades crest in Washington, including the Olympic Mountains and the northeastern region; Alaska to California, east to the Rocky Mountains, also in northeastern North America.
Habitat: Streambanks, moist woods and meadows from middle elevations to the subalpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
ssp. prima – clasping arnica, streambank arnica, streambank leopardbane
Arnica latifoliabroad-leaved arnica, mountain arnica, daffodil leopardbane
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains.
Habitat: Common in forest openings and meadows, and open, rocky areas from middle to high elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica longifolialongleaf arnica, seep spring arnica, spear-leaf leopardbane
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Rocky soil in seeps or springs, cliffs, or riverbanks, from middle elevations to the alpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Arnica molliscordilleran arnica, hairy arnica, cordilleran leopardbane
Distribution: Occurring on both sides of the Cascades crest and in the Olympic Mountains in Washington; Alaska to California, east to the Rocky Mountains.
Habitat: Moist meadows from middle elevations to the alpine.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Arnica nevadensisNevada arnica, Sierra arnica, Sierran leopardbane
Distribution: Occurring in the Cascades and Olympic mountains in Washington; Washington to California, east to Nevada.
Habitat: Open, rocky slopes and forest openings in the subalpine and alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica ovatasticky arnica, sticky-leaf arnica
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Montana and Utah.
Habitat: Rocky places from middle elevations to the subalpine and alpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Arnica parryiParry's arnica
Distribution: Occurring on both sides of the Cascades crest in Washington; Yukon Territory to California, east to the Rocky Mountains.
Habitat: Open woods and meadows, from middle elevations to the alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica rydbergiiRydberg's arnica, subalpine arnica, subalpine leopardbane
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to northern California, east to Alberta and Colorado.
Habitat: Dry meadows and open slopes at high elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica sororiabunch arnica, twin arnica, twin leopardbane
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, and Wyoming.
Habitat: From low elevation prairies and grasslands to coniferous forest openings at middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Aronia melanocarpablack chokeberry
Origin: Introduced
Arrhenatherum elatiustall oatgrass
Distribution: Introduced more commonly west of the Cascades, British Columbia south to California, east to Idaho and Montana.
Habitat: Meadows and pastures.
Origin: Introduced
Flowers: May - July
Growth Duration: Perennial
ssp. bulbosum – bulbous oatgrass
ssp. elatius – bulbous oatgrass
Artemisia absinthiumabsinthe, oldman, wormwood
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across much of North America to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed open areas.
Origin: Introduced from Eurasia
Flowers: July-September
Growth Duration: Perennial
Artemisia annuasweet Annie, sweet sagewort, annual wormwood
Distribution: Occurring in scattered locations east of the Cascades crest and in the Columbia River Gorge in Washington; Washington to California, east across most of North America to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed open places.
Origin: Introduced from Eurasia
Flowers: August-October
Growth Duration: Annual
Artemisia arbusculadwarf sagebrush, low sagebrush
Distribution: Occurring east of the Cascades crest in Washington; central Washington to California, east to the Rocky Mountains.
Habitat: Open, dry plains and hills in sagebrush desert.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
ssp. arbuscula – little sagebrush, low sagebrush
Artemisia biennisbiennial wormwood
Distribution: Occurring on both sides of the Cascades crest and in the Columbia River Gorge in Washington; Alaska to California, east across most of North America to the Atlantic Coast, where considered introduced.
Habitat: Roadsides, fields, irrigation ditches, streambanks, and other disturbed open areas, especially in sandy soil.
Origin: Native
Flowers: August-October
Growth Duration: Annual, Biennial
Artemisia campestrisPacific sagewort, northern wormwood
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast; also in Eurasia.
Habitat: Open places, often in sandy or rocky soil, from low elevations to alpine.
Origin: Native
Flowers: July-September
Growth Duration: Biennial, Perennial
var. borealis – northern wormwood
var. scouleriana – Pacific sagewort, Scouler's wormwood
var. wormskioldii – Columbia Islands sagewort, Wormskiold's wormwood sagewort
Artemisia canahoary sagebrush, silver sagebrush
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Meadows and forest openings from low to middle elevations in the mountains.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
ssp. bolanderi – Bolander's hairy sagebrush
Artemisia douglasianaDouglas's mugwort, Douglas's sagewort, Douglas's wormwood
Distribution: Occurring on both sides of the Cascades crest and in the Columbia River Gorge in Washington; Washington to California, east to Nevada.
Habitat: Mostly along stream banks and river bottoms.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Artemisia dracunculusdragon sagewort, tarragon, dragon wormwood
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to the Great Plains and Great Lakes region.
Habitat: Sagebrush desert to ponderosa pine forest openings at middle elevations.
Origin: Native
Flowers: July-October
Growth Duration: Perennial
Artemisia frigidaprairie sagebrush, prairie sagewort
Distribution: Occurring east of the Cascades crest in Washington; Alaska to Washington, east to the Great Plains, Great Lakes region, and northeastern North America.
Habitat: Dry, open sagebrush plains and foothills.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Artemisia furcatathree-forked mugwort, forked wormwood
Distribution: Occurring in the Cascades and Olympic Mountains of Washington; Alaska to Washington, east to Northwest Territories, Alberta, and Nunavut.
Habitat: Open, rocky ledges and talus slopes in the subalpine and alpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Artemisia ludovicianawestern mugwort, prairie sage
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Meadows and open slopes, from the lowlands to the alpine.
Origin: Native
Flowers: June-October
Growth Duration: Perennial
ssp. candicans – gray sagewort
ssp. incompta – intermediate sagewort, mountain wormwood
ssp. lindleyana – Lindley's western mugwort, Lindley's prairie sage
ssp. ludoviciana – western mugwort, Louisiana sagewort, silver wormwood
Artemisia michauxianaMichaux's mugwort, lemon sagewort, Michaux's wormwood
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta and Wyoming.
Habitat: Rocky places in the mountains at rather high elevations.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Artemisia norvegicamountain sagewort, boreal wormwood
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.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
ssp. saxatilis – mountain sagewort
Artemisia rigidascabland sagebrush, stiff sagebrush
Distribution: Occurring east of the Cascades crest in Washington; Washington to Oregon, east to Idaho and Montana.
Habitat: Dry, rocky places from the plains and foothills to moderate elevations in the mountains.
Origin: Native
Flowers: September-October
Growth Duration: Perennial
Artemisia spiciformissnowfield sagebrush, spiked sagebrush
Distribution: Occurring east of the Cascades crest in Washington; central Washington to California, east to southwestern Montana, Wyoming, and Colorado.
Habitat: Cool, moist slopes, from middle elevations to subalpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Artemisia stellerianadusty miller, oldwoman, beach wormwood, Steller's wormwood
Distribution: Occurring west of the Cascades crest along the northeastern coast of the Olympic Peninsula in Washington; native to Alaska, also occurring from the Great Lakes region east to northeastern North America.
Habitat: Coastal dunes and beaches in developed coastal areas, where escaping from cultivation.
Origin: Introduced
Flowers: May-September
Growth Duration: Perennial
Artemisia suksdorfiicoastal mugwort, Suksdorf's sagewort, coastal wormwood
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California.
Habitat: Bluffs, beaches, rocky areas, and riverbanks, especially near the coast.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Artemisia tilesiiAleutian mugwort, Cascade wormwood
Distribution: Occurring in the Olympic and Cascade Mountains of Washington; Alaska to Oregon, east to Montana, and east across Canada to Quebec.
Habitat: Open rocky or gravelly, wet or dry sites, from middle elevations to the alpine, descending to sea level northward.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Artemisia tridentatabig sagebrush
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Dry plains and foothills to the subalpine, but not in lithosol or alkaline soil.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
ssp. tridentata – big sagebrush
ssp. vaseyana – mountain big sagebrush, Vasey sagebrush
ssp. wyomingensis – Wyoming sagebrush
Artemisia tripartitacut-leaf sagebrush, threetip sagebrush
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon and Nevada, east to Idaho and Wyoming.
Habitat: Sagebrush desert and grasslands.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
ssp. tripartita – cutleaf sagebrush, threetip sagebrush
Artemisia vulgarismugwort, lobed wormwood
Distribution: Occurring on both sides of the Cascades crest and in the Columbia River Gorge in Washington; Alaska to Oregon, east to Montana, east across Canada to the Great Lakes region and eastern North America.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed, open areas.
Origin: Introduced from Eurasia
Flowers: August-October
Growth Duration: Perennial
Arum italicumItalian arum, Italian lords and ladies
Distribution: Occurring west of the Cascades crest in lowland western Washington; southwestern British Columbia to California; also in scattered location in central and eastern U.S.
Habitat: Forest understory and disturbed locations near urbanized areas.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial
ssp. italicum – Italian arum, Italian lords and ladies
Aruncus dioicussylvan goatsbeard
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to Alberta, also in the eastern half of North America.
Habitat: Moist forest and forest edge from low elevations to the subalpine.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
var. acuminatus – Sylvan goatsbeard
Asarum caudatumwild ginger
Distribution: Widely distributed throughout Washington except in central lowlands; British Columbia to California, east to Idaho and Montana.
Habitat: Moist, shady woods at low to mid-elevations in the mountains.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Asclepias cryptocerasHumboldt milkweed, pallid milkweed
Distribution: Occurring east of the Cascades crest in southeastern Washington; southeastern Washington to California, east to Idaho, Wyoming, and Colorado.
Habitat: Gravelly to heavy clay soil in the foothills and lower mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Asclepias fascicularisMexican whorled milkweed, narrow-leaf milkweed
Distribution: Occurring east of the Cascades crest in Washington; northeastern Washington to Baja California, Mexico, east to Idaho, Utah, and Arizona.
Habitat: Sagebrush desert, usually along vernal stream beds.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
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
Origin: Introduced?
Flowers: August
Growth Duration: Perennial
Asclepias speciosashowy milkweed
Distribution: Occurring east of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to Mexico, east to the Great Plains and Great Lakes region.
Habitat: Riparian corridors, irrigation ditches, roadsides, and other at least seasonally wet areas at low elevations, often in loam soils.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Askellia pygmaealow hawksbeard
Distribution: Occurring in the Olympic and Cascades mountains in Washington; Alaska to California, east to Nunavut and Colorado, also in northeastern Canada; Asia.
Habitat: Talus, scree, moraines, sandy or gravelly slopes, subalpine to alpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Asparagus officinalisasparagus
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Atlantic Coast.
Habitat: Garden escape, often of roadsides, fields, wastelots, and other disturbed areas..
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Perennial
Asperugo procumbenscatchweed, madwort
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to the Great Plains, also in eastern North America.
Habitat: Roadsides, fields, irrigation ditches, and other disturbed open areas where moist.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Annual
Aspidotis densaOregon cliff-brake, Indian's dream, podfern
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Idaho and Montana.
Habitat: Cliff crevices and moist, rocky slopes, foothills to near timberline, often on serpentine
Origin: Native
Growth Duration: Perennial
Asplenium trichomanesmaidenhair spleenwort
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, also in southern Rocky Mountain states and in central U.S. and eastern North America.
Habitat: Cliff crevices, rocky outcroppings, and talus slopes, generally where moist.
Origin: Native
Spores: May-September
Growth Duration: Perennial
ssp. quadrivalens – maidenhair spleenwort
ssp. trichomanes – maidenhair spleenwort
Asplenium viridegreen spleenwort
Distribution: Occurring on 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.
Origin: Native
Growth Duration: Perennial
Astragalus agrestiscock's-head, field milk vetch, purple milk vetch
Distribution: Occurring east of the Cascades crest in Washington; Yukon Territory to California, east across North America to Canada\\'s Atlantic Coast.
Habitat: Moist spots in sagebrush plains, and mountain meadows to alpine slopes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Astragalus alpinusalpine milk-vetch, purple milk-vetch
Distribution: Occurring in the northcentral region of Washington; Alaska to northeastern Oregon and northeastern Nevada, east to the Rocky Mountains; circumpolar.
Habitat: Open slopes and rocky areas from upper montane to alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
var. alpinus – alpine milk-vetch
Astragalus arrectushanging pod milk-vetch, Palouse milk-vetch
Distribution: Known from Lincoln and Whitman counties in Washington; eastern Washington to adjacent Idaho.
Habitat: Sagebrush flats to open ponderosa pine forest.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus arthuriArthur's milk-vetch
Distribution: Known only from Asotin County in Washington; southeastern Washington to northeastern Oregon and adjacent west-central Idaho.
Habitat: Grassy hills and rocky meadows, often on basalt.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus arthurii
Origin: Native
Growth Duration: Perennial
Astragalus asotinensisAsotin milk-vetch
Distribution: Known only from Asotin County in Washington; Endemic to Snake River Canyon of southeastern Washington and adjacent Idaho.
Habitat: Grassy slopes in shrub-steppe at low to moderate elevations.
Origin: Native
Flowers: March-May
Growth Duration: Perennial
Astragalus australisIndian milk-vetch, subarctic milk-vetch
Distribution: Occurring in the Olympic Mountains in Washington; Alaska south in the Rocky Mountains to northeastern Oregon, Nevada, Utah, and Colorado, east to the Great Plains and eastern Canada.
Habitat: Foothill bluffs and riverbanks to subalpine and alpine ridges and scree.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
var. cottonii – Cotton's milk-vetch, Cotton's milkvetch
Astragalus beckwithiiBeckwith's milk-vetch
Distribution: Occurring in the southeastern region of Washington; southeastern Washington to northeastern Nevada, east to western Idaho along the Snake River drainage, also disjunct in Kamloops, British Columbia.
Habitat: Sagebrush desert to dry hillsides.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
var. weiserensis – Beckwith's milk-vetch
Astragalus canadensisCanada milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Prairies, stream banks, ditches, ponderosa pine forest openings, and seasonally moist alkaline flats in sagebrush.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
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 along the Snake River corridor to Oregon and southwestern Idaho.
Habitat: Grasslands, dry and sandy slopes in shrub-steppe habitat.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Astragalus cicerchickpea milk-vetch
Distribution: In scattered locations chiefly east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountain states and in eastern North America.
Habitat: Roadsides, fields, dry slopes, and other disturbed areas, often where moist or wet.
Origin: Introduced from Europe
Flowers: July-August
Growth Duration: Perennial
Astragalus collinushill milk-vetch, hillside milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to Oregon, east to west-central Idaho along the Snake and Clearwater Rivers.
Habitat: Basaltic grasslands and sagebrush deserts.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
var. collinus – hillside milk-vetch
Astragalus columbianusColumbian milk-vetch
Distribution: Endemic to east of the Cascades crest in south-central Washington.
Habitat: Dry, open areas in shrub-steppe.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Astragalus conjunctusbasalt milk-vetch, stiff milk-vetch
Distribution: Occurring east of the Cascades crest from south-central to southeastern Washington; Washington to southeast Oregon and adjacent southwestern Idaho.
Habitat: Sagebrush grasslands to brushy slopes and ponderosa pine forest openings.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
var. rickardii – stiff milk-vetch
Astragalus cusickiiCusick's milk-vetch
Distribution: Occurring in the southeastern corner in Washington; Washington to northeastern Oregon, east to central Idaho.
Habitat: Sagebrush plains to grassy or rocky slopes, often on talus.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
var. cusickii – Cusick's milk vetch
Astragalus diaphanusJohn Day milk-vetch, transparent milk-vetch
Distribution: Known historically from Klickitat County in Washington, but now thought to be extirpated; Klickitat County, Washington south to Wheeler and Grant counties in Oregon.
Habitat: Gravel bars, alluvial slopes, and in thin gravelly soil overlying basaltic rock.
Origin: Native
Flowers: May-June
Growth Duration: Annual, Biennial
Astragalus eucosmuselegant milk-vetch
Distribution: Known only from Okanogan County in Washington; Alaska to Montana and east-central Idaho, Wyoming, Utah, and Colorado, east to northeastern North America.
Habitat: Montane forests and meadows.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus falcatusRussian milk-vetch, sickle milk-vetch
Distribution: Known from Whitman County in Washington; British Columbia to Washington and Montana, also in a few scattered locations across North America.
Habitat: Disturbed, open areas.
Origin: Introduced from Eurasia
Flowers: July
Growth Duration: Perennial
Astragalus filipesbasalt milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to northeast California, east to Nevada and Idaho.
Habitat: Sagebrush plains and lower foothills.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus geyeriGeyer's milk-vetch
Distribution: Occurring east of the Cascades crest in south-central Washington; southeastern Oregon to Nevada and California, east to Montana, Wyoming, and Utah, disjunct in British Columbia and along Columbia River of Washington and north-central Oregon.
Habitat: Sandy desert areas, especially on dunes.
Origin: Native
Flowers: June-July
Growth Duration: Annual, Biennial
var. geyeri – Geyer's milk-vetch
Astragalus hoodianusHood River milk-vetch
Distribution: Occurring in the east end of the Columbia River Gorge in Klickitat County in Washington; Klickitat County, Washington to Hood River and Wasco counties in Oregon.
Habitat: Dry, open areas in sagebrush and grasslands.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus howelliiHowell's milk-vetch
Distribution: Occurring in the southeastern corner in Washington; southeastern Washington to north-central Oregon.
Habitat: Stony hillsides among sagebrush and bunchgrass, often over basalt.
Origin: Native
Flowers: Arpil-June
Growth Duration: Perennial
Astragalus inflexusbent milk-vetch, hairy milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; south-central Washington to Oregon, east to Idaho and Montana.
Habitat: Dry hillsides in sagebrush desert.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Astragalus kentrophytathistle milk-vetch, spiny milk-vetch
Distribution: Known historically from Walla Walla County but considered extirpated; southern Alberta to east-central California, east to Rocky Mountains and northern Great Plains.
Habitat: Sandy deserts to alpine ridges.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
var. douglasii – spiny millk-vetch, thistle milk-vetch
Astragalus laxmanniiLaxmann's milk-vetch, standing milk-vetch
Distribution: Occurring in north-central and eastern Washington; Yukon Territory to Washington, east to the Rocky Mountains and Minnesota.
Habitat: Prairies to rocky foothills in sagebrush desert and ponderosa pine forest.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
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.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus lentiginosusfreckled milk-vetch, specklepod milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Montana and Texas.
Habitat: Open areas, desert flats to subalpine slopes.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
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.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus microcystislesser-bladder milk-vetch
Distribution: Occurring in the northeastern counties of Washington; southern British Columbia to Washington, east to Montana and Wyoming.
Habitat: Prairies and foothills to ponderosa pine forests.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Astragalus miselluspauper milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; Washington to Oregon.
Habitat: Dry, open areas in shrub-steppe.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
var. pauper – pauper milk-vetch
Astragalus miserweedy milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to central Washington, Rocky Mountains and northern Great Plains.
Habitat: Grasslands and foothills to montane forests, dry ridges and occasionally alpine meadows.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
var. miser – weedy milk-vetch
var. serotinus – weedy milk-vetch
Astragalus pulsiferaeAmes's milk-vetch
Distribution: Known only from Mt. Adams and Klickitat County in Washington; Occurring in the northern Sierra Nevada of California and adjacent Nevada; not reported from Oregon.
Habitat: Sandy and gravelly flats in sagebrush and open pine forests on basalt.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
var. suksdorfii – Ames's milk-vetch
Astragalus purshiiPursh's milk-vetch, woolly-pod milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Prairies and sagebrush deserts, foothills and lower mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
var. glareosus – woolly-pod milk-vetch
var. purshii – Pursh's milk-vetch, woolly-pod milk-vetch
Astragalus reventiformisYakima milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; Washington to Sherman County in Oregon.
Habitat: Shrub-steppe to low, dry, open ponderosa pine forests.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus reventusBlue Mts. milk-vetch, longleaf milk-vetch
Distribution: Occurring east of the Cascades crest in the southeastern counties in Washington; Washington to northeastern Oregon.
Habitat: Pondersoa pine forest openings at low to moderate elevations.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus ripariusPiper's milk-vetch
Distribution: Occurring east of the Cascades crest in the southeastern counties in Washington; southeastern WA east to adjacent Idaho.
Habitat: Dry bluffs and canyon banks.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus robbinsiiRobbins's milk-vetch
Distribution: Occurring east of the Cascades crest in the northern counties in Washington; Alaska to Oregon,east to Alberta and south in the Rocky Mountains to Colorado, also in eastern North America.
Habitat: Stream banks and alpine slopes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
var. minor – Robbin's milk-vetch
Astragalus sclerocarpusstalked-pod milk-vetch, The Dalles milk-vetch, woody-pod milk-vetch
Distribution: Occurring east of the Cascades crest chiefly in the Columbia River Basin and Columbia River Gorge in Washington; south-central British Columbia to north-central Oregon.
Habitat: Dunes and sandy barrens, low elevation
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus sheldoniiSheldon's milk-vetch
Distribution: Occurring east of the Cascades crest in Asotin County in Washington; southeastern Washington to Oregon, east to Idaho.
Habitat: Shrub-steppe and ponderosa pine forest openings.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus sinuatusWhited's milk-vetch
Distribution: Endemic to Chelan County in Washington.
Habitat: Among sagebrush on rocky hillsides.
Origin: Native
Flowers: May
Growth Duration: Perennial
Astragalus spaldingiiSpalding's milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; central Washington to northeast Oregon, east to western Idaho.
Habitat: Sagebrush and grasslands in the foothills and valleys.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus speirocarpuscurve-pod milk-vetch, medic milk-vetch, spiral-pod milk-vetch
Distribution: Endemic to Washington from Kittitas County south to Klickitat County, east to Grant County,
Habitat: Sagebrush desert.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Astragalus succumbenscrouching milk-vetch, sprawling milk-vetch
Distribution: Occurring east of the Cascades crest in Washington from Kittitas and Grant counties south; Washington to Umatilla and Gilliam Counties, Oregon.
Habitat: Sagebrush deserts, sandy barrens and lower foothills.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus tenelluspulse milkvetch
Distribution: Disjunct in Douglas County in Washington; Yukon to southeastern Oregon and Nevada, east to Rocky Mountains.
Habitat: Prairies and foothills to lower mountains.
Origin: Native
Flowers: May
Growth Duration: Perennial
Astragalus tweedyiTweedy's milk-vetch
Distribution: Occurring east of the Cascades crest in Washington, from Yakima County south; central Washingtonto north-central Oregon near the Columbia River and lower Deschutes River.
Habitat: Sagebrush plains and foothills.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus whitneyiballoon milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; central Washington south to California, east to Idaho and Nevada.
Habitat: High, open, rocky ridges and slopes, often in serpentine.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
var. sonneanus – balloon milk-vetch
Athyrium distentifoliumalpine lady-fern
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Alberta, Montana, Wyoming and Colorado; also in northeastern Canada and Greenland.
Habitat: Open, rocky slopes and along streams at mid- to high elevations in the mountains.
Origin: Native
Growth Duration: Perennial
ssp. americanum – American alpine lady-fern
Athyrium filix-feminalady-fern
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast; circumboreal.
Habitat: Moist woods, meadows, forest edge, and shaded riparian corridors from low to middle elevations.
Origin: Native
Spores: May-September
Growth Duration: Perennial
ssp. cyclosorum – lady fern, northwestern lady fern
Athysanus pusillussandweed
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Montana.
Habitat: Dry, open, often grassy places.
Origin: Native
Flowers: March-June
Growth Duration: Annual
Atocion armeriasweet William catchfly
Distribution: Occurring in scattered locations west of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Wastelots, roadsides, and other disturbed areas.
Origin: Introduced from Europe
Flowers: June-July
Growth Duration: Annual
Atriplex argenteasilver orache, silverscale orache
Origin: Native
Flowers: July - September
Growth Duration: Annual, Perennial
var. argentea – silver saltbush, silverscale
Atriplex canescensfourwing saltbush, hoary saltbush, shadscale, wingscale
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to the Great Plains.
Habitat: Saline areas in the prairies.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
var. canescens – hoary saltbush
Atriplex dioicathickleaf orache, saline saltbush
Distribution: Occurring on both sides of the Cascades crest in Washington, but particularly common along the inner and outer marine coast; Yukon Territory to California, east to the Atlantic Coast.
Habitat: Salt marshes, sea beaches and headlands, also inland on disturbed or saline ground;
Origin: Native
Flowers: June-September
Growth Duration: Annual
Atriplex gardneriGardner's saltbush
Distribution: Occurring at low elevations in central Washington; Alberta south to California, east to the Great Plains.
Habitat: Sagebrush-steppe desert.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
var. falcata – moundscale, gardner's saltbush, sickle saltbush, saltsage
Atriplex gmeliniiGmelin's orache, Gmelin's saltbush
Distribution: Occurring west of the Cascades crest along the coast in Washington; Alaska to California.
Habitat: On coastal beaches, strands, and rocky outcroppings near the high tide in saline soil.
Origin: Native
Flowers: June-September
Growth Duration: Annual
var. gmelinii – Gmelin's orache, Gmelin's saltbush
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.
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Annual
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.
Origin: Introduced from Asia
Flowers: July-August
Growth Duration: Annual
Atriplex littoralisgrassleaf orache, narrow-leaved orache
Origin: Introduced from Europe
Flowers: June - September
Growth Duration: Annual, Perennial
Atriplex longipeslong-stalked orache, Baltic saltbush
Origin: Introduced
Atriplex oblongifoliaoblongleaf orache
Origin: Introduced from Europe
Growth Duration: Annual
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.
Origin: Introduced from Eurasia
Flowers: June-September
Growth Duration: Annual
Atriplex prostratafat hen, hastate orache, thin-leaf orache
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia 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.
Origin: Introduced from Eurasia
Flowers: June-September
Growth Duration: Annual
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.
Origin: Introduced from Eurasia
Flowers: July-September
Growth Duration: Annual
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.
Origin: Introduced from Australia
Flowers: April-September
Growth Duration: Perennial
Atriplex truncatawedge orache, wedgeleaf orache, wedgescale orache
Origin: Native
Flowers: June - August
Growth Duration: Annual
Atropa belladonnabelladonna, deadly nightshade
Origin: Introduced
Growth Duration: Perennial
Aubrieta deltoidearockcress
Habitat: Disturbed areas, where escaping from nearby cultivation.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial
Aucuba japonica
Origin: Introduced
Avena barbatabarbed oat
Distribution: Introduced and common in southwest United States; occasional in Washington and western Oregon.
Habitat: Roadsides and waste land.
Origin: Introduced
Flowers: May - June
Growth Duration: Annual
Avena fatuawild oat
Distribution: Common introduction in most of western North America.
Habitat: A weed in grain fields, roadsides and waste ground.
Origin: Introduced
Flowers: May - September
Growth Duration: Annual
Avena sativaoat
Distribution: Commonly cultivated throught the United States and Canada, occasionally escaping but usually not persisting.
Habitat: Roadsides and field margins.
Origin: Introduced
Flowers: June - August
Growth Duration: Annual
Azolla filiculoidesduckweed fern, Pacific mosquito-fern
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Idaho and western Montana.
Habitat: Ponds, backwaters, and slow-moving streams.
Origin: Native
Growth Duration: Annual
Azolla microphyllaMexican mosquito-fern
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Texas.
Habitat: Ponds and backwaters, mostly at low elevations.
Origin: Native
Growth Duration: Annual, Perennial