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: On both sides of the Cascades in Washington; Alaska south to Siskiyou County, California, mostly west of the Cascade Crest.
Habitat: Mostly at 1000-4000 feet elevation in the mountains.
Origin: Native
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
Abies lasiocarpaalpine fir, subalpine fir
Distribution: Widely distributed throughout much of Washington; Alaska south to southern Oregon, east in the higher mountains to Alberta, Canada, and Colorado.
Habitat: Subalpine to alpine slopes, where commonly in krumholtz form.
Origin: Native
Cones: June-July
ssp. bifolia – Rocky Mountain subalpine fir
ssp. lasiocarpa – subalpine fir
Abies proceranoble fir
Distribution: Chiefly west of the Cascades in Washington; from northern Washington to the Siskiyou Mountains in California, and in the Coast Range in Oregon.
Habitat: Deep forests where there is sufficient moisture, moderate to fairly high elevations.
Origin: Native
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
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
Abronia umbellatapink sandverbena
Distribution: Distributed along the coast in Washington; along the coast from British Columbia south to Baja California.
Habitat: Coastal sandy beaches and adjacent dunes.
Origin: Native
Flowers: May-September
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
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
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
var. douglasii – Douglas maple
Acer macrophyllumbig-leaf maple
Distribution: Occurring on both sides 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
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
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
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
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
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
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
Achlys californicadeer's-foot
Distribution: On both sides of the Cascades and in the Olympic Mountains in Washington; British Columbia south to California.
Habitat: Moist areas in deep woods to open parks.
Origin: Native
Flowers: April-July
Achlys triphylladeerfoot, sweet-after-death, vanillaleaf
Distribution: Both sides of the Cascades in Washington; British Columbia south to California.
Habitat: Moist areas in deep woods to forest openings.
Origin: Native
Flowers: April-July
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
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
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
ssp. lemmonii – Lemmon's needlegrass
Achnatherum nelsonii
Origin: Native
ssp. dorei – Nelson's needlegrass
ssp. nelsonii – Nelson's needlegrass
Achnatherum nevadenseNevada needlegrass
Origin: Native
Achnatherum occidentalecommon western needlegrass
Origin: Native
ssp. californicum – California needlegrass
ssp. pubescens – western needlegrass
Achnatherum richardsoniiRichardson's rice grass
Origin: Native
Flowers: June - July
Achnatherum thurberianumThurber's rice grass
Origin: Native
Flowers: Late May - June
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
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
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
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
Aconitum columbianumColumbian monkshood
Distribution: Alaska to California, east to Montana and New Mexico.
Habitat: Moist woods and meadows, moderate to subalpine elevations.
Origin: Native
Flowers: June-August
ssp. columbianum – 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
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
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
Acorus calamussweet flag
Origin: Introduced from Eurasia
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
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
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
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
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
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
var. aleuticum – Aleutian maidenhair fern, western maidenhair fern
Adonis aestivalissummer pheasant's-eye
Distribution: Introduced and occasionallhy escaping, but marginally persistant; uncommon in the Pacific Northwest.
Habitat: Disturbed areas.
Origin: Introduced from Europe
Flowers: June
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
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
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
Agastache occidentaliswestern giant-hyssop
Distribution: East slopes of the Cascades, Chelan to Yakima Counties, Washington; south to Oregon.
Habitat: Dry, open, often rocky slopes at low to moderate elevations.
Origin: Native
Flowers: June-August
Agastache urticifolianettle-leaf giant-hyssop
Distribution: East of the Cascades in Washington; British Columbia to California, east to Colorado.
Habitat: Dry open slopes and draws, foothills to mid-elevations in the mountains
Origin: Native
Flowers: May-August
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
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
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
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
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
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
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
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
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
Agrimonia gryposepalatall hairy grooveburr
Origin: Native
×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
Agropyron fragileSiberian wheatgrass
Origin: Introduced
Agrostemma githagocommon corncockle
Distribution: Introduced and well established in Washington; also occurring in Oregon, less common in Idaho and Montana.
Habitat: Roadsides and wasteland.
Origin: Introduced, European
Flowers: June-July
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
Agrostis castellanaHighland bent, dryland browntop
Origin: Introduced
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
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
Agrostis idahoensisIdaho bent
Origin: Native
Flowers: July - August
Agrostis mertensiiMerten's bentgrass, northern bentgrass
Origin: Native
Flowers: July - August
Agrostis microphyllasmall-leaf bent
Origin: Native
Flowers: May - June
Agrostis ×murbeckii
Origin: Introduced
Agrostis oregonensisOregon bent
Origin: Native
Flowers: July - August
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
Agrostis scabrarough bent
Origin: Native
Flowers: June - August
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
Agrostis variabilisalpine bent
Origin: Native
Flowers: Late July - September
Ailanthus altissimatree-of-heaven
Distribution: Occurring mostly east of the Cascades in Washington, but also in scattered localities west of the Cascades; widely distributed throughout North America.
Habitat: Escaped ornamental in roadsides, waste areas, along railroad tracks, and other open, disturbed areas.
Origin: Introduced from China
Flowers: May-July
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
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
Ajuga reptanscarpet bugle
Distribution: Occurring 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
Alhagi maurorumcamelthorn
Distribution: Occurring east of the Cascades crest in Washington; Washington, Idaho, and California east to Colorado and Texas.
Habitat: Disturbed areas in arid lands at low to moderate elevations.
Origin: Introduced from Asia
Flowers: June-August
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
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
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
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
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
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
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
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
Allium campanulatumrosy Sierra onion
Distribution: In the mountains in eastern Oregon, California dnd Nevada, and on Bethel Ridge, Yakima County, Washington.
Habitat: Dry soils at medium to high elevations.
Origin: Native
Flowers: June - July
Allium cernuumnodding onion
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to Oregon, east to the Rocky Mountains; also in central and southeastern U.S.
Habitat: Open, somewhat moist areas, sea level to high elevations in the mountains.
Origin: Native
Flowers: May-July
Allium columbianumColumbia onion
Distribution: Occurring in easternmost Washington; east to Idaho and Montana.
Habitat: Seasonally wet soils on rock outcrops, wet meadows.
Origin: Native
Flowers: May-July
Allium constrictumGrand Coulee onion
Distribution: Grant and Douglas Counties, Washington.
Habitat: Shallow, vernally-moist soils in low, open areas.
Origin: Native
Flowers: May - July
Allium crenulatumOlympic onion, scalloped onion
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to Oregon.
Habitat: Forest openings and mountain meadows, moderate to high elevations.
Origin: Native
Flowers: May-July
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
Allium douglasiiDouglas' onion
Distribution: East of the Cascades in Washington; central and eastern Washington south to northeastern Oregon.
Habitat: Open, vernally-moist areas at low to moderate elevations.
Origin: Native
Flowers: May-July
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
Allium geyeriGeyer's onion
Distribution: From the Cascades east in Washington and northern Idaho; disjunct in South Dakota, Utah and Texas.
Habitat: Low meadows and along streams.
Origin: Native
Flowers: May - June
var. geyeri – Geyer's onion
var. tenerum – Rydberg's onion
Allium macrumrock onion
Distribution: In Washington, Kittitas and Douglas Counties south to Walla Walla and Klickitat Counties; more common in north-central Oregon.
Habitat: Lithosol and barren, gravelly soils in the shrub-steppe.
Origin: Native
Flowers: April - May
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
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
Allium sativumcultivated garlic
Distribution: West of the Cascades in Washington.
Habitat: Disturbed areas near towns, cities, agricultural fields where cultivated.
Origin: Introduced
Flowers: May-July
var. sativum – garlic
Allium schoenoprasumchives
Distribution: Across southern Canada and northern United States; in Washington, along the Wenatchee and Columbia Rivers
Habitat: Wet meadows, rocky or gravelly streambanks and lake shores
Origin: Both native and introduced populations
Flowers: April - August
Allium scilloidesfragile onion, scilla-like onion
Distribution: Douglas County to Klickitat County, Washington, lower foothills of the Cascades to east of the Columbia River
Habitat: Scablands and dry, barren, gravelly soils.
Origin: Native
Flowers: March - April
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
Allium tolmieiTolmie's onion
Distribution: South-east Washington; eastern Oregon, western Idaho and north-east California.
Habitat: Rocky, gravelly or clayey soils, generally with sparse cover.
Origin: Native
Flowers: April-July
var. tolmiei – Tolmie's onion
Allium tuberosum
Origin: Introduced
Allium validumPacific onion, swamp onion
Distribution: Occurring in the Olympic Mountains and West Cascades in Washington; southern British Columbia to California, east to Idaho and northern Nevada.
Origin: Native
Flowers: June - August
Allium vinealewild chives, crow garlic, wild garlic
Distribution: Scattered localities throughout Washington.
Habitat: Disturbed areas.
Origin: Introduced from Europe
Flowers: June - August
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
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
Alnus incanamountain alder
Distribution: Occurring east of the Cascades crest in Washington; Alaska south to New Mexico, also in the north-central and northeastern region of North America.
Habitat: Moist places, streamside, low to high elevations.
Origin: Native
Flowers: March-May
ssp. tenuifolia – mountain alder
Alnus rhombifoliaCalifornia alder, white alder
Distribution: Chiefly east of the Cascades crest in Washington; Washington south to California and Nevada, east to Idaho.
Habitat: Near streams at low elevations.
Origin: Native
Flowers: January-April
Alnus rubraOregon alder, red 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
Alnus viridisgreen alder, mountain alder
Distribution: Widely distributed throughout the mountainous areas of Washington; Alaska south to California, east across the northern half of North America to the Atlantic Coast.
Habitat: Moist areas, low to high elevations.
Origin: Native
Flowers: May-July
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
Alopecurus arundinaceuscreeping meadow-foxtail
Origin: Introduced
Alopecurus carolinianustufted meadow-foxtail
Origin: Introduced
Flowers: May - July
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
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
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
Alopecurus saccatusPacific meadow-foxtail
Origin: Native
Flowers: May - June
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
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
Alyssum muraleyellowtuft
Origin: Introduced
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
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
Amaranthus blitumlivid amaranth, pale amaranth
Origin: Introduced from the tropics
Amaranthus californicusCalifornia amaranth
Origin: Native
Flowers: July - October
Amaranthus caudatus
Origin: Introduced
Amaranthus cruentusblood amaranth, caterpillar amaranth, purple amaranth
Origin: Probably introduced from cultivation in Central America
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
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
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
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
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
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
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
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
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
Amelanchier alnifoliasaskatoon, serviceberry
Distribution: Occurring throughout 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
Amelanchier utahensisUtah serviceberry
Distribution: Occurring east of the Cascades crest in Washington; Washington south to Baja California, east to the Rocky Mountains.
Habitat: Rimrock, valleys, gullies and hillsides, from sagebrush desert to mid-elevations in the mountains.
Origin: Native
Flowers: May-June
Ammannia coccineavalley redstem
Distribution: Known only from a restoration site in King County; California east along Mexican border to central and eastern U.S.
Habitat: Restored wetland.
Origin: Introduced
Flowers: June-August
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
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
Amphiscirpus nevadensisNevada bulrush
Origin: Native
Amsinckia intermediafireweed fiddleneck, rancher's fiddleneck
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south, both sides of the Cascades, 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
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
Amsinckia menziesiiharvest fiddleneck, rigid fiddleneck, rancher's fireweed
Distribution: Chiefly east of the Cascades in Washington; Washington south to California.
Habitat: Open, dry foothills.
Origin: Native
Flowers: April-July
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
Amsinckia spectabilisseaside amsinckia
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to California.
Habitat: Coastal dunes or sandy bluffs.
Origin: Native
Flowers: May-July
var. spectabilis – woolly breeches, Scouler's fiddleneck, seaside fiddleneck
Amsinckia tessellatatessellate fiddleneck
Distribution: Chiefly east of the Cascades in Washington; British Columbia south to California, east to Idaho, south to New Mexico.
Habitat: Roadsides and dry, open slopes and flats, often in disturbed soil.
Origin: Native
Flowers: April-June
var. tessellata – 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
Anchusa azureaItalian alkanet, Italian bugloss
Distribution: Scattered localities in Washington; British Columbia south to California, scattered localities east of the Cascades to the Atlantic Coast.
Habitat: Disturbed soil.
Origin: Introduced from Old World
Flowers: June-August
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
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
var. polifolia – bog rosemary
Androsace filiformisslender-stem rock-jasmine
Origin: Native
Flowers: June - July
Androsace septentrionalisnorthern fairy-candelabra, rock jasmine, pygmyflower
Distribution: Northern Washington; circumpolar in the arctic, widespread in Canada, pacific coast of the United States east to Dakotas, Minnesota, and Texas.
Habitat: Alpine meadows.
Origin: Native
Flowers: May-August
Anemone deltoideathreeleaf 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
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
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
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
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
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
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
Anemone patenspasqueflower, prairie-crocus
Distribution: Occurring east of the Cascades crest in the Wenatchee Mountains in Washington, where disjunct from the main species range 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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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 middle elevations in the mountains.
Origin: Native
Flowers: May-August
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
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
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
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
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
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
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
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
Anticlea elegansglaucous death camas
Distribution: In the Olympic Mountains of Washington and across the northern border east of the Cascacdes crest; Alaska to Oregon, south in the Rockies to New Mexico, east across Canada and the northern United States to Virginia.
Habitat: Meadow, open forests and rocky slopes, mid- to high elevations in the mountains.
Origin: Native
Flowers: June-August
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
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
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
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
Aphanes australissmall-fruited parsley-piert
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to Washington, also in southeastern U.S.
Habitat: Disturbed, open areas at low elevations.
Origin: Introduced
Flowers: March-May
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
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
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
ssp. corymbosum – flat-topped broomrape
ssp. mutabile – flat-topped broomrape
Aphyllon fasciculatumclustered broomrape
Distribution: Occurring chiefly 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 mainly on Artemisia, Eriogonum, Eriophyllum, Galium, and Phacelia.
Origin: Native
Flowers: May-July
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
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
Aphyllon purpureumpurple broomrape
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 montange, often where open and seasonally moist, parasitic mainly on Asteraceae, Saxifragaceae, Sedum.
Origin: Native
Flowers: April-August
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
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
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
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
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
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
var. formosa – red Columbine, Sitka Columbine, western Columbine
Aquilegia vulgarisEuropean Columbine
Distribution: Introduced as a garden flower, occasionally escaping.
Habitat: Disturbed soil near gardens.
Origin: Introduced
Flowers: May-July
Arabidopsis kamchaticalyreleaved cress, kamchatka rockcress, lyre-leaved rockcress, western rockcress
Distribution: Occurring only 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
Arabidopsis thalianamouse-ear cress, thalecress
Distribution: Widely distributed througout Washington; widely distributed throughout North America.
Habitat: Disturbed areas, particularly near cities and towns.
Origin: Introduced from Eurasia
Flowers: March-May
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
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
Arabis eschscholtzianahairy rockcress, Pacific coast rockcress
Distribution: Occurring on both sides of the Cascades in Washington; Alaska south to California, east to the northern Rocky Mountains.
Habitat: Open areas, often in waste places, from sea level to mid-elevations in the mountains.
Origin: Native
Flowers: April-July
Arabis furcataCascade rockcress, Columbia Gorge rockcress, fork-haired rockcress
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington south to Oregon.
Habitat: Open slopes, meadows, and ridgelines in alpine and subalpine areas.
Origin: Native
Flowers: May-July
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
Arabis olympicaOlympics rockcress
Origin: Native
Aralia nudicauliswild sarsaparilla
Distribution: Occurring in northeastern region of Washington; Eastern British Columbia, east to the Atlantic Coast, and south in the mountains to Colorado.
Habitat: Moist, shaded soil.
Origin: Native
Flowers: May-June
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
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
Arceuthobium abietinumfir dwarf-mistletoe
Origin: Native
Arceuthobium americanumlodgepole pine dwarf-mistletoe
Distribution: Chiefly east of the Cascades crest in Washington; southern British Columbia south to California, east to Montana, Colorado and New Mexico.
Habitat: Parasitic on Pinus, usually on Pinus contorta.
Origin: Native
Flowers: April- June
Arceuthobium campylopodumwestern dwarf-mistletoe
Distribution: In the Pacific Northwest on Pinus contorta and P. ponderosa (Compare range of these two species)
Habitat: Parasitic on Pinus contorta and P. ponderosa, sea level to mid-elevations in the mountains
Origin: Native
Flowers: Late June - September
Arceuthobium douglasiiDouglas-fir dwarf-mistletoe
Distribution: British Columbia to California, east to Montana and New Mexico.
Habitat: On the branches of Pseudotsuga menziesii.
Origin: Native
Flowers: May - June
Arceuthobium laricislarch dwarf-mistletoe
Origin: Native
Arceuthobium tsugensehemlock dwarf mistletoe
Origin: Native
ssp. tsugense – hemlock mistletoe
Arcteranthis cooleyaeCooley's buttercup
Distribution: Alaska and the Cascades of British Columbia, known in Washington from Mt. Colonel Bob in the Olympics and Del Campo Peak Snohomish county.
Habitat: Damp slopes and rocky crevices at high elevations, blossoming as snow recedes.
Origin: Native
Flowers: June-August
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
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
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
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
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
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
Arctostaphylos uva-ursired bearberry, kinnikinnik
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
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
Arenaria serpyllifoliathyme-leaf sandwort
Distribution: Widely distributed across Washington; introduced in most of North America.
Habitat: Weed in various habitats.
Origin: Introduced from Europe
Flowers: May-July
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
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
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
ssp. californica – sea-pink, thrift
ssp. maritima – sea-pink, thrift
Armoracia rusticanahorseradish
Distribution: Occurring in scattered locations in eastern portion of Washington; British Columbia south to California, east across the U.S. and Canada to the Atlantic Coast.
Habitat: Disturbed areas including fields, roadsides and wastelots.
Origin: Introduced from Eurasia
Flowers: May-July
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Arum italicumItalian lords and ladies, large cuckoo pint
Distribution: Known from lowlands west of Cascades crest in Washington; southwestern British Columbia to California; scattered location in central and eastern U.S.
Habitat: Forest understory and disturbed locations near urbanized areas.
Origin: Introduced from Europe
Flowers: April-June
ssp. italicum – large cuckoo pint, Italian lords and ladies
Aruncus dioicusSylvan goatsbeard
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska south to California.
Habitat: Moist woods, low to mid-elevations in the mountains.
Origin: Native
Flowers: May-July
var. acuminatus – Sylvan goatsbeard
Asarum caudatumwild ginger
Distribution: Widely distributed throughout Washington except in central lowlands; British Columbia to Oregon, east to Idaho and Montana.
Habitat: Moist, shady woods at low to mid-elevations in the mountains.
Origin: Native
Flowers: April-July
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
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
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
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
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
Asparagus officinalisasparagus
Distribution: Introduced throughout the United States
Habitat: Garden escape, often of roadsides.
Origin: Introduced from Eurasia
Flowers: July - August
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
Aspidotis densaOregon cliff brake, Indian's dream, podfern
Distribution: British Columbia to California, east to Idaho and Montana
Habitat: Cliff crevices and moist, rocky slopes, foothills to near timberline, often on serpentine
Origin: Native
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 and talus slopes, generally where moist.
Origin: Native
Spores: May-September
ssp. quadrivalens – maidenhair spleenwort
ssp. trichomanes – maidenhair spleenwort
Asplenium viridegreen spleenwort
Distribution: Both sides of the Cascades crest in Washington; Alaska to California, east across northern North America to New England and the Canadian Maritimes; circumboreal.
Habitat: Cliff crevices, especially on limestone, often near or above timberline.
Origin: Native
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
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
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
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
Astragalus arthurii
Origin: Native
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Astragalus sinuatusWhited's milk-vetch
Distribution: Endemic to Chelan County in Washington.
Habitat: Among sagebrush on rocky hillsides.
Origin: Native
Flowers: May
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
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
Astragalus succumbenscrouching milk-vetch, sprawling milk-vetch
Distribution: Occurring east of the Cascades crest in Washington from Kittitas and Grant counties south; Washington south to Umatilla and Gilliam Counties, Oregon.
Habitat: Sagebrush deserts, sandy barrens and lower foothills.
Origin: Native
Flowers: April-June
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
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
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
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
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
ssp. cyclosorum – lady fern, northwestern lady fern
Athysanus pusillussandweed
Distribution: Both sides of the Cascades in Washington; British Columbia south to California, east to Idaho.
Habitat: Dry, open, often grassy places.
Origin: Native
Flowers: March-June
Atocion armeriasweet William catchfly
Distribution: Introduced as an ornmental and occasionally escaping throughout North America.
Habitat: Disturbed soil and wasteland.
Origin: Introduced
Flowers: June - July
Atriplex argenteasilver orache, silverscale orache
Origin: Native
Flowers: July - September
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
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
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
var. falcata – moundscale, gardner's saltbush, sickle saltbush, saltsage
Atriplex gmeliniiGmelin's orache
Distribution: Occurring along the coast in Washington; Alaska south to California.
Habitat: On coastal beaches, strands, and rocky outcroppings near the high tide in saline soil.
Origin: Native
Flowers: June-September
var. gmelinii – Gmelin's saltbush orach
Atriplex heterospermaorach, Russian atriplex orach
Distribution: Primarily east of the Cascades crest in Washington; occurring in scattered locations throughout North America.
Habitat: Riparian zones and adjacent fields; tolerant of alkaline.
Origin: Introduced from Eurasia
Flowers: June-August
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
Atriplex littoralisgrassleaf orache, narrow-leaved orache
Origin: Introduced from Europe
Flowers: June - September
Atriplex longipeslong-stalked orache, Baltic saltbush
Origin: Introduced
Atriplex oblongifoliaoblongleaf orache
Origin: Introduced from Europe
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
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
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
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
Atriplex truncatawedge orache, wedgeleaf orache, wedgescale orache
Origin: Native
Flowers: June - August
Atropa belladonnabelladonna, deadly nightshade
Origin: Introduced
Aubrieta deltoidea
Origin: Introduced
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
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
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
Azolla filiculoidesduckweed fern, large mosquito fern
Distribution: Occurring on both sides of the Cascades in Washington; British Columbia to California, east to Idaho and western Montana.
Habitat: Ponds, backwaters, slow-moving streams.
Origin: Native
Azolla microphyllaMexican waterfern fern, 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