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: Both sides of the Cascades in Washington; introduced noxious weed, common in eastern United States, uncommon in the Pacific Northwest.
Habitat: Rich, moist soils in gardens, cultivated fields and waste areas.
Origin: Introduced
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: Chiefly east of the Cascades in Washington; south-central British Columbia south to California, east to Montana and Arizona.
Habitat: Valleys to mid-elevations in the mountains, often in ponderosa pine forests.
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 south 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: Silver Star Mountain, Skamania County, Washington and the base of Mt. Hood, Oregon.
Habitat: Moist woods at moderate elevations.
Origin: Native
Flowers: June-August
Actaea rubrabaneberry
Distribution: Widely distributed throughout Washington; Alaska south to California, east to the Atlantic Coast.
Habitat: Moist woods and streambanks from low elevations to moderate elevations in the mountains.
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 mertensiinorthern bent
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
Alcea roseahollyhock
Distribution: In a few scattered locations in Washington; widely distributed throughout much of North America.
Habitat: Garden escape establishing in disturbed areas.
Origin: Introduced
Flowers: May-August
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: Currently restricted to a few counties west of the Cascades in Washington; Alaska south to Utah, east across Canada and the U.S. to the Atlantic Coast.
Habitat: Disturbed soil and waste ground.
Origin: Introduced from Europe
Flowers: April-June
Allium acuminatumtaper-tip onion
Distribution: Widely distributed across Washington; British Columbia south to California, east to Wyoming.
Habitat: Common in dry, open, often rocky areas, low to moderate elevations in the mountains.
Origin: Native
Flowers: May-July
Allium amplectensnarrow-leaf onion
Distribution: Scattered locations on both sides of the Cascades crest in Washington; British Columbia south to California.
Habitat: Dry slopes and open meadows at low to moderate elevations.
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: Blue Mountains of southeast Washington.
Habitat: Open, fairly dry, rocky areas.
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: East slope and foothills of the Cascades, Kittitas County, Washington, south to Wasco County, Oregon
Habitat: Open areas where the soil is wet into the spring
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: Both sides of the Cascades in Washington; British Columbia south to California.
Habitat: Deep humus of coniferous forests at low to moderate elevations.
Origin: Native
Flowers: May-August
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 laevis
Origin: Introduced
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; widely distributed from the tropics to much of North America.
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 throughout Washington, but mostly east of the Cascades; occurring throught much of western North America, the upper Midwest, and northeastern U.S.
Habitat: Disturbed areas.
Origin: Introduced from Mediterranean region
Flowers: May-July
Andromeda polifolia
Distribution: Likely in northern Washington; Alaska to Newfoundland, south in the U.S. to Idaho.
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: On both sides of the Cascades in the southern half of Washington; Washington south to California.
Habitat: Moist to drier areas in open to deep woods at low to moderate elevations.
Origin: Native
Flowers: April-May
Anemone drummondiiDrummond's anemone
Distribution: Occurring in the Olympic and Cascade Mountains in Washington; Alaska south to California, east to Montana.
Habitat: Alpine and subalpine regions.
Origin: Native
Flowers: June-August
var. drummondii – Drummond's anemone
var. lithophila – Drummond's anemone, Little Belt Mountain anemone
Anemone lyalliilittle mountain anemone, Lyall's anemone
Distribution: Chiefly west of the Cascades but occasionally on the east slope in Washington; British Columbia to California.
Habitat: Open prairies at low elevations to subalpine ridges.
Origin: Native
Flowers: March-July
Anemone multifidacliff anemone, Pacific anemone
Distribution: Alaska to California, east to Nebraska and New Mexico in the west, and across the northern tier of states to Maine
Habitat: From the foothills to high elevations in the mountains
Origin: Native
Flowers: May-August
var. multifida – cliff anemone, Pacific anemone
var. saxicola – hirsute anemone
Anemone occidentaliswestern pasqueflower
Distribution: In the Olympic and the Cascade mountains in Washington; British Columbia south to California, east to Montana and the Wallowa Mountains of Oregon.
Habitat: Mountain slopes and meadows at mid- to high elevations.
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
Distribution: Occurring in scattered locaions in Washington; Alaska south to the Cascades of northern Washington, east to the Atlantic Coast, south in the Rocky Mountains to Colorado.
Habitat: Mountain meadows and subalpine stream banks.
Origin: Native
Flowers: May-August
Anemone patenspasqueflower, prairie-crocus
Distribution: East of the Cascades crest in Washington; Alaska south to the Wenatchee Mountains of Washington, east to the Rocky Mountains and northern Great Plains.
Habitat: Prairies to mountain slopes, mostly on well-drained soil.
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 everlasting, flagellate pussytoes, whip pussytoes
Distribution: East of the Cascades in Washington and Oregon, east to Wyoming
Habitat: Shrub-steppe to dry, open areas at mid-elevations, often in lithosol
Origin: Native
Flowers: April-July
Antennaria geyeriGeyer's pussytoes, pinewoods pussytoes
Origin: Native
Flowers: July - August
Antennaria howellii
Distribution: British Columbia to Oregon, east to Montana
Habitat: Open woods at low to moderate elevations; not common.
Origin: Native
Flowers: May - July
ssp. howellii – Howell's pussytoes
ssp. neodioica – Blue Mountains everlasting, field pussytoes
Antennaria lanatawoolly everlasting, woolly pussytoes
Distribution: Both sides of the Cascades in Washington; British Columbia south to Oregon, east to Alberta and Wyoming.
Habitat: Mountain meadows near timberline.
Origin: Native
Flowers: July-September
Antennaria luzuloidessilvery brown everlasting, woodrush pussytoes
Distribution: Chiefly east of the Cascades in Washington. British Columbia south to California, east to Colorado and South Dakota.
Habitat: Open, moderately dry areas from foothills to mid-elevations in the mountains.
Origin: Native
Flowers: May-July
ssp. luzuloides – silvery brown everlasting, woodrush pussytoes
Antennaria mediaalpine pussytoes, Rocky Mountain pussytoes
Distribution: Circumboreal, south at high elevations in the mountains to California and Arizona
Habitat: Uncommon in high mountain meadows
Origin: Native
Flowers: June - September
Antennaria microphyllarosy everlasting, desert pussytoes, elegant pussytoes, pulvinate pussytoes, rosy pussytoes, small-leaf pussytoes
Distribution: Alaska to California, east to North Dakota and Arizona, from lower montane to sub-alpine.
Habitat: Moist, open areas, flood plains of streams, margins of alkali depressions.
Origin: Native
Flowers: June - July
Antennaria monocephalapygmy pussytoes
Origin: Native
Antennaria parvifolialittle-leaf pussytoes
Distribution: Eastern base of the Rocky Mountains, extending westward rarely to eastern Washington and British Columbia.
Habitat: Foothills and dry open areas to moderate elevations.
Origin: Native
Flowers: May-July
Antennaria pulcherrimashowy pussytoes
Origin: Native
Flowers: May - August
Antennaria racemosaslender everlasting, Hooker's pussytoes, raceme pussytoes
Distribution: Widely distributed throughout the forested and mountainous areas of Washington; British Columbia south to California, east to the northern Rocky Mountains.
Habitat: Open, modertely dry areas from low to mid-elevations in the mountains.
Origin: Native
Flowers: May-August
Antennaria stenophyllanarrowleaved pussytoes
Distribution: East of the Cascades crest in Washington; Washington south to Nevada, east to Idaho.
Habitat: Shrub-steppe, dry meadows and open woods.
Origin: Native
Flowers: April-June
Antennaria umbrinellabrown everlasting, brown-bract pussytoes, umber pussytoes
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains.
Habitat: Uncommon in openings in the forest at moderate elevations.
Origin: Native
Flowers: May-August
Anthemis arvensiscorn chamomile, field chamomile
Distribution: Introduced in much of the United States; more common west of the Cascades in Washington
Habitat: Roadsides, disturbed areas
Origin: Introduced
Anthemis cotulamayweed chamomile, stinking chamomile, dogfennel
Distribution: Introduced throughout the United States
Habitat: Weed of roadsides and disturbed area
Origin: Introduced
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: West of the Cascades in Washington; British Columbia south 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; widely distributed throughout much of North America except the central U.S.
Habitat: Disturbed areas including roadsides, wastelots, and forest openings.
Origin: Introduced
Flowers: August-October
Arctium minuscommon burdock, lesser burdock
Distribution: Introduced throughout the United States
Habitat: Weed of roadsides and disturbed area
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 south to California.
Habitat: Moist, open woods.
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 nevadensiskinnikinnick, pinemat manzanita
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington south to California, east to Nevada.
Habitat: Chiefly in the mountains at mid-elevations.
Origin: Native
Flowers: May-July
ssp. nevadensis – pinemat manzanita
Arctostaphylos patulagreen-leaf manzanita
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Montana and Colorado.
Habitat: Low elevations in the mountains.
Origin: Native
Flowers: May-June
Arctostaphylos uva-ursired bearberry, kinnikinnik
Distribution: Widely distributed throughout 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 in the Cascades and northeastern corner of Washington; Alaska south to California, east across Canada and to the Rockies in the U.S.
Habitat: Meadows and wet places at moderate elevations.
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 fulgenshillside arnica, orange arnica, shining leopardbane
Distribution: British Columbia to California, uncommon east to North Dakota; east of the Cascades in Washington and Oregon
Habitat: Open places from the foothills to moderate elevations in the mountains
Origin: Native
Flowers: May - July
Arnica gracilisslender arnica, slender leopardbane
Distribution: Occurring in mountainous areas throughout Washington; British Columbia south to California, east to Colorado and Utah.
Habitat: Rocky places, usually at rather high elevations in the mountains.
Origin: Native
Flowers: June-July
Arnica lanceolataclasping arnica, stream bank arnica
Distribution: Cascades Mountains to the coast in Washington; Alaska to California, east to western Montana.
Habitat: Streambanks and moist woods at moderate to mid-elevations in the mountains.
Origin: Native
Flowers: June-August
ssp. prima – clasping arnica, streambank arnica, streambank leopardbane
Arnica latifoliabroad leaved arnica, mountain arnica, daffodil leopardbane
Distribution: Both sides of the Cascades in Washington; Alaska south through Washington.
Habitat: Common in open forests and open, rocky areas at mid- to high elevations in the mountains.
Origin: Native
Flowers: June-August
Arnica longifolialongleaf arnica, seep spring arnica, spear-leaf leopardbane
Distribution: Southern Alberta south to Washington, Colorado and California.
Habitat: Rocky soil in seeps or springs, cliffs, or riverbanks, at moderate to high elevations in the mountains.
Origin: Native
Flowers: July - September
Arnica molliscordilleran arnica, hairy arnica, cordilleran leopardbane
Distribution: In the mountains from British Columbia to California, east to Alberta and Colorado
Habitat: Frequent in moist meadows at mid- to high elevations in the mountains
Origin: Native
Flowers: June - September
Arnica nevadensisNevada arnica, Sierra arnica, Sierran leopardbane
Distribution: Cascade and Olympic Mountains of Washington, south to California; rare in our range.
Habitat: Open, rocky slopes at high elevations in the mountains.
Origin: Native
Flowers: July - August
Arnica ovatasticky arnica, sticky leaf arnica
Distribution: Both sides of the Cascades in Washington; Alaska south to California, east to Montana and Utah.
Habitat: Rocky places at moderate to high elevations in the mountains.
Origin: Native
Flowers: July-September
Arnica parryiParry's arnica
Distribution: In the mountains from British Columbia to California, east to Alberta and Colorado
Habitat: Open woods and meadows, moderate to mid-elevations in the mountains
Origin: Native
Flowers: July - 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: July - August
Arnica sororiabunch arnica, twin arnica, twin leopardbane
Distribution: Chiefly east of the Cascades, British Columbia to California, east to Wyoming.
Habitat: Open, often rather dry places, but usually vernally moist, in the foothills and at moderate elevations in the mountains.
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: Introduced in the northern half of the United States and southern Canada
Habitat: Weed of roadsides and waste places
Origin: Introduced
Flowers: July - September
Artemisia annuasweet Annie, sweet sagewort, annual wormwood
Distribution: Native of Eurasia, naturalized in eastern United States, rare in the Pacific Northwest.
Habitat: Fields and waste places.
Origin: Introduced
Flowers: August - October
Artemisia arbusculadwarf sagebrush, low sagebrush
Distribution: East of the Cascades in Washington; Pacific Northwest, east into Montana
Habitat: Open, dry plains and hills at moderate to high elevations.
Origin: Native
Flowers: July - September
ssp. arbuscula – little sagebrush, low sagebrush
Artemisia biennisbiennial wormwood
Distribution: Native in the Pacific Northwest, but widely distributed elsewhere as a weed.
Habitat: Waste places and streambanks, especially in sandy soil.
Origin: Native? Disputed native (BC) or introduced (Chambers and Sundberg 2000)
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. 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 south to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Meadows and forest openings from valley bottoms to moderate elevations in the mountains.
Origin: Native
Flowers: July-September
Artemisia douglasianaDouglas mugwort, Douglas sagewort, Douglas wormwood
Distribution: Occurring in Washington chiefly east of the Cascades crest, but also on the west side; widely distributed throughout much of North America.
Habitat: Mostly along stream banks and river bottoms.
Origin: Native
Flowers: August-September
Artemisia dracunculusdragon sagewort, tarragon, dragon wormwood
Distribution: Occurring east of the Cascades crest in Washington; widely distributed throughout the central and western portions of North America.
Habitat: Shrub-steppe to dry, open areas at mid-elevations.
Origin: Native
Flowers: July-October
Artemisia frigidaprairie sagebrush, prairie sagewort
Distribution: Rocky Mountains and Great Plains states, occasionally in eastern Washington and British Columbia
Habitat: Dry, open plains and foothills
Origin: Native
Flowers: July - September
Artemisia furcatathree-forked mugwort, forked wormwood, three-forked wormwood
Distribution: Occurring in the Cascades and Olympic Mountains of Washington; Alaska south to Washington, east to Northwest Territories, Alberta, and Nunavut.
Habitat: Open, rocky ledges and talus slopes at high elevations in the mountains.
Origin: Native
Flowers: July-September
Artemisia ludovicianawestern mugwort, prairie sage
Distribution: Occurring on both sides of the Cascades in Washington; distributed widely throughout North America.
Habitat: Fairly dry areas from the foothills to high elevations in the mountains.
Origin: Native
Flowers: June-October
ssp. candicans – gray sagewort
ssp. incompta – intermediate sagewort, mountain wormwood
ssp. ludoviciana – western mugwort, Louisiana sagewort, silver wormwood
Artemisia michauxianaMichaux's mugwort, lemon sagewort, Michaux's wormwood
Distribution: British Columbia to California, east to Alberta and Wyoming.
Habitat: Rocky places in the mountains at rather high elevations.
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 south 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
Origin: Native
Artemisia stellerianadusty miller, oldwoman, beach wormwood, Steller's wormwood
Distribution: Known from a few locations along the north coast in Washington; known only from Washington in western North America; central Canada and U.S. to the Atlantic Coast.
Habitat: Coastal dunes and beaches.
Origin: Introduced
Flowers: May-September
Artemisia suksdorfiicoastal mugwort, Suksdorf's sagewort, coastal wormwood
Distribution: Occurring west of the Cascades crest in Washington, British Columbia south to California.
Habitat: Bluffs and rocky or sandy beaches, less commonly in other low, open places.
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 across Canada.
Habitat: Open rocky or gravelly, wet or dry sites, mostly at high elevations in the mountains, 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 south to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Dry plains and hills up to timberline, but not in lithosol or alkaline soil.
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 south to Oregon, east to Idaho and Nevada.
Habitat: Sagebrush-steppe grasslands and desert.
Origin: Native
Flowers: July-September
ssp. tripartita – cutleaf sagebrush, threetip sagebrush
Artemisia vulgarismugwort, lobed wormwood
Distribution: Introduced from Europe, now established in most of eastern United States and adjacent Canada; uncommon in the Pacific Northwest.
Habitat: Waste areas and disturbed soil.
Origin: Introduced
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 cryptoceraspallid milkweed
Distribution: Asotin County, Washington and Grant County, Oregon, to Payette County, Idaho, south to California and Colorado.
Habitat: Gravelly to heavy clay soil in the hills and lower mountains.
Origin: Native
Flowers: April - June
Asclepias fascicularisnarrow-leaf milkweed
Distribution: East of the Cascades in Washington; east to Idaho and Utah, reaching the coast in Oregon.
Habitat: Uncommon in shrub-steppe, usually along vernal stream beds.
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: Chiefly east of the Cascades in Washington; British Columbia east to Manitoba, south to Mexico.
Habitat: Open areas at low elevations in dry to moist, loamy to sandy soil
Origin: Native
Flowers: June-August
Askellia pygmaealow hawksbeard
Distribution: Occurring in the Olympic and Cascades mountains in Washington; Alaska to California, east to Nunavut, Alberta, Montana, Wyoming, and CO; northeastern North America; Asia.
Habitat: Uncommon above timberline in the mountains.
Origin: Native
Flowers: July-August
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