Vascular Plants

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


Browse by scientific name:
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Scientific names beginning with A:
106 genera
368 species, 112 subspecies and varieties
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Index to genera:
Abies, Abronia, Abutilon, Acer, Achillea, Achlys, Achnatherum, Acmispon, Aconitum, Aconogonon, Acorus, Actaea, Adelinia, Adenocaulon, Adiantum, Adonis, Aegilops, Aegopodium, Aesculus, Agalinis, Agastache, Ageratina, Agoseris, Agrimonia, Agropogon, Agropyron, Agrostemma, Agrostis, Ailanthus, Aira, Ajuga, Alcea, Alhagi, Aliciella, Alisma, Alliaria, Allium, Allotropa, Alnus, Alopecurus, Alstroemeria, Alyssum, Amaranthus, Amauropelta, Ambrosia, Amelanchier, Ammannia, Ammophila, Amorpha, Amphiscirpus, Amsinckia, Anaphalis, Anchusa, Andromeda, Androsace, Anemone, Anethum, Angelica, Anisocarpus, Antennaria, Anthemis, Anthoxanthum, Anthriscus, Anticlea, Antirrhinum, Apera, Aphanes, Aphyllon, Apium, Apocynum, Aquilegia, Arabidopsis, Arabis, Aralia, Arbutus, Arceuthobium, Arcteranthis, Arctium, Arctostaphylos, Arenaria, Aristida, Armeria, Armoracia, Arnica, Aronia, Arrhenatherum, Artemisia, Arum, Aruncus, Asarum, Asclepias, Askellia, Asparagus, Asperugo, Aspidotis, Asplenium, Astragalus, Athyrium, Athysanus, Atocion, Atriplex, Atropa, Aubrieta, Aucuba, Avena, Azolla
Abies amabilis – Pacific silver fir
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to northern California.
Habitat: Mostly at 1000-4000 feet elevation in the mountains.
Origin: Native
Growth Duration: Perennial
Abies grandis – grand fir
Distribution: Occurring on both sides of the Cascades crest in Washington; Vancouver Island, British Columbia to California, east to Idaho and Montana.
Habitat: Coniferous forests, from sea level to mid-elevations in the mountains.
Origin: Native
Cones: May-June
Growth Duration: Perennial
Abies lasiocarpa – alpine fir, subalpine fir
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains.
Habitat: Subalpine to alpine slopes, where commonly in krumholtz form.
Origin: Native
Cones: June-July
Growth Duration: Perennial
• ssp. bifolia – Rocky Mountain subalpine fir
• ssp. lasiocarpa – subalpine fir
Abies procera – noble fir
Distribution: Occurring chiefly west of the Cascades crest in Washington; northern Washington to the Siskiyou Mountains in northern California.
Habitat: Deep forests where there is sufficient moisture, moderate to fairly high elevations.
Origin: Native
Growth Duration: Perennial
Abronia latifolia – yellow sand verbena
Distribution: Occurring west of the Cascades crest in Washington along the coast; Vancouver Island, British Columbia to California.
Habitat: Coastal beaches and sand dunes.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Abronia mellifera – honey-scented sandverbena, white sand verbena
Distribution: Occurring east of the Cascades crest in Washington; eastern Washington to southeastern Oregon, east to Montana and western Wyoming.
Habitat: Dunes and sandy soil at low elevations.
Origin: Native
Flowers: May-October
Growth Duration: Perennial
• var. mellifera – honey-scented sandverbena, white sand verbena
Abronia umbellata – pink sand verbena
Distribution: Occurring west of the Cascades crest along the outer coast in Washington; British Columbia to Baja California.
Habitat: Coastal sandy beaches and adjacent dunes.
Origin: Native
Flowers: May-September
Growth Duration: Perennial
• var. breviflora – sand verbena
Abutilon theophrasti – velvetleaf
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, wastelots, and other disturbed open places.
Origin: Introduced from Eurasia
Flowers: July-August
Growth Duration: Annual
Acer campestre – field 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 circinatum – vine maple
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to northern California.
Habitat: Moist woods from sea level to mid-elevations in the mountains.
Origin: Native
Flowers: March-June
Growth Duration: Perennial
Acer glabrum – Rocky Mountain maple
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains and Great Plains.
Habitat: Moist woods from sea level to mid-elevations in the mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
• var. douglasii – Douglas maple
Acer macrophyllum – big-leaf maple
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to southern California.
Habitat: Moist woods from sea level to middle elevations in the mountains.
Origin: Native
Flowers: March-June
Growth Duration: Perennial
Acer negundo – box elder, box elder maple
Distribution: Occurring chiefly east of the Cascades in Washington; widely distributed throughout much of North America.
Habitat: Occasionally escapes from cultivation, chiefly in disturbed areas or riparian zones.
Origin: Introduced from eastern North America, escaped from cultivation
Flowers: April-June
Growth Duration: Perennial
Acer platanoides – Norway maple
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon, east to Idaho and Montana; invasive in eastern North America.
Habitat: Forest edge, riparian zones, fields, and other disturbed areas where escaped from cultivation.
Origin: Introduced from Europe
Flowers: April-May
Growth Duration: Perennial
Acer pseudoplatanus – sycamore maple
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Oregon, east to Montana, also in eastern North America.
Habitat: Forest edge, fields, and other disturbed areas where escaped from cultivation.
Origin: Introduced from Europe
Flowers: April-May
Growth Duration: Perennial
Acer saccharinum – silver maple
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Idaho and Montana, also in central and eastern North America where native.
Habitat: Riparian corridors, moist bottomlands, and other areas near water, often disturbed.
Origin: Introduced from central and eastern North America
Flowers: March-April
Growth Duration: Perennial
Achillea millefolium – milfoil, yarrow
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Atlantic Coast; circumboreal
Habitat: Common in open, dry to somewhat moist areas from low to high elevations; tolerant of disturbance.
Origin: Both native and introduced populations
Flowers: February-October
Growth Duration: Perennial
Achillea ptarmica – pearl yarrow
Distribution: Reported from Washington but no specimens seen; Alaska to Oregon, east in scattered locations across North America to the Atlantic Coast.
Habitat: Roadsides, wastelots, and other disturbed open areas where occasinally escaping from cultivation.
Origin: Introduced from Eurasia
Flowers: May-August
Growth Duration: Annual, Perennial
Achlys californica – California deer's-foot, California vanilla leaf
Distribution: Occurring on both sides of the Cascades and in the Olympic Mountains in Washington; British Columbia to California.
Habitat: Moist areas in deep woods to open parks.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Achlys triphylla – deer's-foot, vanilla leaf
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California.
Habitat: Moist areas in deep woods to forest openings.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
• ssp. triphylla – deerfoot, vanillaleaf
Achnatherum hendersonii – Henderson's needlegrass
Distribution: Occurring east of the Cascades crest in Douglas, Kittitas, and Yakima counties; central Washington to Jefferson County, Oregon.
Habitat: Dry, rocky, shallow soil, in sagebrush desert or ponderosa pine forest openings.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Achnatherum hymenoides – Indian ricegrass
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Great Plains.
Habitat: Grasslands, desert plains, and foothills, especially on rocky or sandy soil.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Achnatherum lemmonii – Lemmon's needlegrass
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east to the Rocky Mountains.
Habitat: Grassy balds, prairies, sagebrush grasslands, and ponderosa pine forest, from the lowlands to middle elevations in the mountains.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
• ssp. lemmonii
Achnatherum nelsonii – Nelson's needlegrass
Distribution: Occurring chiefly east of the Cascades crest in Washington; Yukon Territory to California, east to the northern Great Plains and Colorado.
Habitat: Moist to mesic, montane to subalpine meadows and open forest.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• ssp. dorei – Nelson's needlegrass
• ssp. nelsonii – Nelson's needlegrass
Achnatherum occidentale – western needlegrass
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Grassland, sagebrush desert, and coniferous forests from low to middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
• ssp. californicum – California needlegrass
• ssp. pubescens – western needlegrass
Achnatherum richardsonii – Richardson's ricegrass
Distribution: Occurring east of the Cascades crest in Washington; Alaska to northeastern Oregon, east to the Canadian Great Plains and south in the Rocky Mountains to Colorado.
Habitat: Sandy and gravelly sites in grassland, open forest, and sagebrush grassland.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Achnatherum thurberianum – Thurber's ricegrass
Distribution: Occurring east of the Cascades crest in Washington; south-central British Columbia to California, east to Montana, Wyoming, and Colorado.
Habitat: Sagebrush grassland and ponderosa pine forest.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Acmispon americanus – American bird's-foot trefoil
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Rocky Mountains, south to Mexico.
Habitat: Chiefly in sandy to rocky, exposed or wooded areas, more common at low elevations
Origin: Native
Flowers: April-September
Growth Duration: Annual
• var. americanus – American bird's-foot trefoil
Acmispon denticulatus – riverbar bird's-foot-trefoil
Distribution: Occurring on both sides of the Cascades in Washington; southern British Columbia to California, disjunct in southern Idaho and southwestern Utah.
Habitat: Sandy to rocky soil in open areas at low to moderate elevations.
Origin: Native
Flowers: April-June
Growth Duration: Annual
Acmispon nevadensis
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east to Idaho and Nevada.
Habitat: Open, disturbed areas including road cuts, balds, grasslands, and forest edges at low to moderate elevations.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
• var. nevadensis
Acmispon parviflorus – small-flowered bird's-foot trefoil
Distribution: Occurring chiefly west of the Cascades crest and east in the Columbia River Gorge in Washington; British Columbia to California.
Habitat: Open slopes and sandy flats, seashore into the mountains.
Origin: Native
Flowers: April-September
Growth Duration: Annual
Aconitum columbianum – Columbian monkshood
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains.
Habitat: Moist woods and meadows, moderate to subalpine elevations.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• ssp. columbianum – Columbian monkshood
Aconogonon davisiae – Newberry's fleeceflower, Davis' knotweed, Davis's knotweed
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to California.
Habitat: Slopes and ridges in the subalpine and alpine.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Aconogonon phytolaccifolium – alpine fleeceflower
Distribution: Occurring chiefly east of the Cascades crest in Washington; Washington to California, east to Idaho, Montana, and Nevada.
Habitat: Subalpine to alpine ridges, meadows and talus slopes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• var. phytolaccifolium – poke knotweed
Acorus calamus – sweet flag
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; Washington to California, east to Idaho, also widespread in central and eastern North America.
Habitat: Wetlands, pond shores, and streambanks.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Perennial
Actaea elata – tall bugbane
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to Oregon.
Habitat: Moist, shady woods at low elevations.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• var. elata – tall bugbane
Actaea laciniata – cut-leaved bugbane, Mt. Hood bugbane
Distribution: Occurring west of the Cascades crest in southwestern Washington; southwestern Washington to adjacent northwestern Oregon.
Habitat: Moist woods at middle elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Actaea rubra – baneberry
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Moist woods and streambanks from low elevations to middle elevations in the mountains.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Adelinia grandis – Adeline's hound's-tongue, Pacific hound's-tongue, grand hound
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; Washington to California.
Habitat: Forest openings and meadows at low to moderate elevations.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Adenocaulon bicolor – pathfinder, trailplant
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east the northern Rocky Mountains, northern Great Plains, and Great Lakes region.
Habitat: Moist, shady woods at low to middle elevations.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Adiantum aleuticum – maidenhair fern, northern maidenhair fern
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east sporadically to the Rocky Mountains, also in the Great Lakes region and northeastern North America.
Habitat: Moist woods and streambanks, from low to middle elevations in the mountains.
Origin: Native
Growth Duration: Perennial
• var. aleuticum – Aleutian maidenhair fern, western maidenhair fern
Adonis aestivalis – summer pheasant's-eye
Distribution: Occurring east of the Cascades crest in Washington; central Washington to California, east to Montana, Idaho, and Utah.
Habitat: Disturbed areas.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Annual
Aegilops cylindrica – jointed goatgrass
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across most of the United States to the Atlantic Coast.
Habitat: Waste ground and roadsides; a troublesome weed in wheat.
Origin: Introduced from southern Europe
Flowers: May-July
Growth Duration: Annual
Aegopodium podagraria – bishop's goutweed
Distribution: Occurring in scattered locations west of the Cascades crest in the Puget Trough in Washington; southern British Columbia to Oregon, also in eastern North America.
Habitat: Disturbed forest understory and edge, where often dumped as garden waste.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Perennial
Aesculus hippocastanum – horse-chestnut
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Oregon, also in central and eastern North America.
Habitat: Disturbed forested areas, particularly in urban and suburban areas where the species is planted as a street tree.
Origin: Introduced from Europe
Flowers: May-June
Growth Duration: Perennial
Agalinis paupercula – small-flower false foxglove
Distribution: Occurring west of the Cascades crest, where known from a single locality in Pierce County; native to eastern North America.
Habitat: Lakeshore margins on floating logs.
Origin: Introduced
Flowers: August-September
Growth Duration: Perennial
Agastache occidentalis – western giant-hyssop
Distribution: Occurring east of the Cascades crest in Washington; central Washington to north-central and northeastern Oregon.
Habitat: Dry, open, often rocky slopes at low to moderate elevations.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Agastache urticifolia – nettle-leaf giant-hyssop
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Colorado.
Habitat: Dry open slopes and draws, foothills to middle elevations in the mountains
Origin: Native
Flowers: May-August
Growth Duration: Perennial
• var. urticifolia – nettle-leaf giant-hyssop
Ageratina occidentalis – western boneset, western snakeroot
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Montana, Utah, and Nevada.
Habitat: Rocky places at various altitudes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Agoseris apargioides – seaside agoseris
Distribution: Occurring west of the Cascades crest in Washington along the outer coast. Washington to California.
Habitat: Coastal dunes and beach heads.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• var. maritima – seaside agoseris
Agoseris aurantiaca – orange agoseris
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, Great Plains, and Quebec.
Habitat: Meadows and forest openings at from middle elevations to the alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• var. aurantiaca – orange agoseris, slender agoseris
• var. carnea – pink agoseris
Agoseris ×elata – tall agoseris, tall goat-chicory
Distribution: Occurring on both sides of the Cascades crest in Washington; south-central British Columbia to California.
Habitat: Meadows and open woods, from the valleys to middle elevations in the mountains.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Agoseris glauca – pale agoseris, short-beaked agoseris
Distribution: Occurring chiefly east of the Cascades crest in Washington; Yukon Territory to California, east to the Rocky Mountains, northern Great Plains, and Great Lakes region.
Habitat: Open forests and open areas, from low to high elevations in the mountains.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
• var. dasycephala – pale agoseris, pale goat-chicory
• var. glauca
Agoseris grandiflora – large-flowered agoseris
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Montana, Idaho and Nevada.
Habitat: Prairies, balds, meadows, and forest openings, often where seasonally dry, from low to middle elevations in the mountains.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
• var. grandiflora – large flowered agoseris, large flower goat-chicory
• var. leptophylla – Puget Sound agoseris
Agoseris heterophylla – annual agoseris
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Idaho, Montana, Utah, and Arizona.
Habitat: Dry, open areas at low to mid-elevations.
Origin: Native
Flowers: April-July
Growth Duration: Annual
• var. heterophylla
Agoseris monticola – mountain agoseris, Sierra Nevada agoseris
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Nevada.
Habitat: Mesic meadows in the subalpine and alpine, often in soils of volcanic origin.
Origin: Native
Flowers: July-August
Growth Duration: Perennial
Agoseris retrorsa – spear leaved agoseris, spear leaf goat-chicory
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Nevada, Utah, and Arizona.
Habitat: Sagebrush desert, grassy slopes, and ponderosa pine forest openings at low to middle elevations.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Agrimonia gryposepala – tall hairy agrimony, tall hairy grooveburr
Distribution: Reported from Washington but currently no specimens exist; British Columbia to California, east to the Rocky Mountains.
Habitat: Edges, openings, draws, thickets, and open forest.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Agropyron cristatum – crested wheatgrass
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east across much of North America to the Atlantic Coast.
Habitat: Dry, open areas where distiurbed; frequently planted for soil stabilization and forage.
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Perennial
Agropyron fragile – Siberian wheatgrass
Distribution: Occurring east of the Cascades crest in Washington; south-central British Columbia to southeastern Idaho.
Habitat: Sagebrush desert, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Annual
Agrostemma githago – common corncockle
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Roadsides and wasteland.
Origin: Introduced from Europe
Flowers: June-July
Growth Duration: Annual
• var. githago – common corncockle
Agrostis capillaris – colonial bentgrass
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Open, disturbed areas often at low elevations.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial
Agrostis castellana – Highland bentgrass, dryland browntop
Distribution: Occurring west of the Cascades crest in lowland western Washington: southwestern British Columbia to California.
Habitat: Disturbed sites, roadsides, and gravel bars.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Perennial
Agrostis densiflora – California bentgrass
Distribution: Occurring west of the Cascades crest in western Washington along the outer coast; coastal Washington to California.
Habitat: Coastal bluffs.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Agrostis exarata – spiked bentgrass
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Alberta, Nebraska and Texas.
Habitat: Moist areas, from near sea level to mid-elevations in the mountains.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Agrostis gigantea – black bentgrass
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Atlantic Coast.
Habitat: Disturbed sites, roadsides, edge of agricultural fields, mostly at low elevations.
Origin: Introduced from Eurasia
Flowers: June-September
Growth Duration: Perennial
Agrostis idahoensis – Idaho bentgrass
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Subalpine and alpine meadows, along wet seepage areas, bogs, and wet openings in coniferous forests.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Agrostis mertensii – Merten's bentgrass, northern bentgrass
Distribution: Occurring in the Cascades Range in Washington; Alaska to northern Washington; circumboreal.
Habitat: Rocky alpine meadows and ridgelines.
Origin: Native
Flowers: July-August
Growth Duration: Perennial
Agrostis microphylla – small-leaf bentgrass
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; southwestern British Columbia to California.
Habitat: Seasonally wet areas on thin, rocky or sandy substrates, vernal pools, cliffs, and serpentine areas.
Origin: Native
Flowers: May-June
Growth Duration: Annual
Agrostis oregonensis – Oregon bentgrass
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Montana, Wyoming, and Nevada.
Habitat: Stream and lake margins, damp woodlands and meadows.
Origin: Native
Flowers: July-August
Growth Duration: Perennial
Agrostis pallens – seashore bentgrass
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, east to western Montana and Utah.
Habitat: Coastal sands and cliffs, meadows, open, dry lowlands to subalpine forest.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Agrostis scabra – rough bentgrass
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Disturbed sites in grassl, open forest, marshes, and lakesides, often along roads and ditches.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Agrostis stolonifera – spreading bentgrass
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Wet, disturbed areas that include streambanks, flooded fields, and ditches at low to moderate elevations.
Origin: Introduced from Eurasia
Flowers: June-September
Growth Duration: Perennial
Agrostis variabilis – alpine bentgrass
Distribution: Occurring on both sides of the Cascades crest in Washington British Columbia to California, east to the Rocky Mountains.
Habitat: Wet subalpine and alpine seeps and meadows.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Ailanthus altissima – tree-of-heaven
Distribution: Occurring chiefly east of the Cascades crest in Washington, British Columbia to California, east across most of North America to the Atlantic Coast.
Habitat: Escaped ornamental in roadsides, waste areas, along railroad tracks, and other open, disturbed areas.
Origin: Introduced from China
Flowers: May-July
Growth Duration: Perennial
Aira caryophyllea – silver hairgrass
Distribution: Occurring west of the Cascades crest in Washington and east in the Columbia River Gorge; British Columbia to California, east to Idaho and Wyoming, also in the southeastern U.S. and northeastern North America.
Habitat: Balds, prairies, meadows, forest openings, roadsides, wastelots, and other open areas at low to middle elevations.
Origin: Introduced Eurasia and North Africa
Flowers: May-August
Growth Duration: Annual
• var. caryophyllea – silver hairgrass
Aira praecox – early silver hairgrass
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California; also 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 from Europe
Flowers: April-September
Growth Duration: Annual
Ajuga reptans – carpet bugle
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Oregon, east in scattered locations in Idaho and Montana; widespread in central and eastern North America.
Habitat: Disturbed ground, often in forest understory.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial
Alhagi maurorum – camelthorn
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
Growth Duration: Perennial
Aliciella leptomeria – Great Basin gilia, sand gily-flower
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to the Rocky Mountains.
Habitat: Open, sandy and rocky areas in sagebrush steppe from low to middle elevations.
Origin: Native
Flowers: April-June
Growth Duration: Annual
Aliciella lottiae – Lott's gily-flower
Distribution: Occurring east of the Cascades crest in the south-central portion of Washington; Washington south to California, east to Idaho and Utah.
Habitat: Open, sandy areas in sagebrush-steppe at low to middle elevations.
Origin: Native
Flowers: April-June
Growth Duration: Annual
Alisma gramineum – grass-leaved water-plantain, narrow-leaf water-plantain
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Minnesota and Wisconsin.
Habitat: Marshy areas, often in standing water.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Alisma plantago-aquatica – European water plantain
Distribution: Currently only known from King County in Washington; Alaska, where native, to British Columbia, where also introduced.
Habitat: Marshy areas, sometimes largely submerged.
Origin: Introduced from Eurasia and Alaska
Flowers: June-September
Growth Duration: Perennial
Alisma triviale – northern water plantain
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across much of North America to the Atlantic Coast.
Habitat: Streams, lakes, ponds, wet ditches, wetlands, and cattle ponds.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Alliaria petiolata – garlic mustard
Distribution: Occurring west of the Cascades crest in lowland western Washington; British Columbia to Oregon, also in Utah, widespread from central Great Plains to eastern North America.
Habitat: Disturbed forest understory, often where moist, at low elevations.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Annual, Biennial
Allium acuminatum – taper-tip onion
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east to Wyoming.
Habitat: Balds, grasslands, rocky outcroppings, dry slopes, and other open areas from low to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium amplectens – narrow-leaf onion
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California.
Habitat: Dry slopes and open meadows at low to middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium campanulatum – rosy Sierra onion
Distribution: Occurring east of the Cascades crest where known from Yakima County in Washington; Washington to California, east to Nevada.
Habitat: Dry soils at medium to high elevations.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Allium cernuum – nodding onion
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon, east to the Rocky Mountains; also in central and southeastern U.S.
Habitat: Open, somewhat moist areas, sea level to high elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium columbianum – Columbia onion
Distribution: Occurring east of the Cascades crest in far eastern Washington; Washington to Idaho and Montana.
Habitat: Seasonally wet soils on rock outcrops, wet meadows.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium constrictum – Grand Coulee onion
Distribution: Occurring east of the Cascades crest in Grant and Douglas counties in Washington.
Habitat: Shallow, vernally-moist soils in low, open areas.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium crenulatum – scalloped onion
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon.
Habitat: Forest openings and mountain meadows, moderate to high elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium dictuon – Blue Mountain onion
Distribution: Occurring east of the Cascades crest in Washington, where endemic to Columbia County.
Habitat: Open, fairly dry, rocky areas at low to middle elevations.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Allium douglasii – Douglas' onion
Distribution: Occurring east of the Cascades crest in southeastern Washington; southeastern Washington to eastern Oregon.
Habitat: Open, vernally-moist areas at low to moderate elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium fibrillum – Cuddy Mountain onion, fringed onion
Distribution: Occurring chiefly in the southeastern counties of Washington; Washington east to Montana, south to Oregon.
Habitat: Moist, shallow soils in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium geyeri – Geyer's onion
Distribution: Occurring east of the Cascades crest in Washington; southern Vancouver Island to Arizona, east to the Rocky Mountains and northern Great Plains.
Habitat: Low meadows and along streams.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
• var. geyeri – Geyer's onion
• var. tenerum – bulbil onion, Rydberg's onion
Allium macrum – rock onion
Distribution: Occurring east of the Cascades crest in Washington; central Washington to southern Oregon and southwestern Idaho.
Habitat: Lithosol and barren, gravelly soils in the shrub-steppe.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Allium nevii – Nevius's garlic, Nevius's onion
Distribution: Occurring east of the Cascades crest in central Washington; Chelan County, Washington to Wasco County, Oregon
Habitat: Vernally wet meadows and rocky soils at low to middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Allium robinsonii – Robinson's onion
Distribution: Near the Columbia River in Washington; Washington south to north-central Oregon.
Habitat: Sand and gravel near the river to rocky, even lithosol benches.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Allium sativum var. sativum – garlic
Origin: Introduced from Old World, exact origin unknown
Allium schoenoprasum – chives
Distribution: Occurring east of the Cascades crest in Washington; Alaska to Oregon and Nevada, east to the Rocky Mountains, further east across Canada to the Great Lakes region and eastern North America.
Habitat: Wet meadows, rocky or gravelly streambanks and lake shores
Origin: Both native and introduced populations
Flowers: April - August
Growth Duration: Perennial
Allium scilloides – fragile onion, scilla-like onion
Distribution: Occurring east of the Cascades crest, where endemic in Washington from Douglas to Klickitat counties.
Habitat: Scablands and dry, barren, gravelly soils.
Origin: Native
Flowers: March-April
Growth Duration: Perennial
Allium tolmiei – Tolmie's onion
Distribution: Occurring east of the Cascades crest in southeastern Washington; southeastern Washington to adjacent western to Idaho, south to northeastern California.
Habitat: Rocky, gravelly or clayey soils, generally with sparse cover.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
• var. tolmiei – Tolmie's onion
Allium validum – Pacific onion, swamp onion
Distribution: Occurring at Mount Rainier in Washington, where disjunct; Washington to California, east to Idaho and northern Nevada.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Allium vineale – wild chives, crow garlic, wild garlic
Distribution: Occurring chiefly west of the Cascades crest in Washington; southwestern British Columbia to California; also in eastern North America.
Habitat: Disturbed areas.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial
Allotropa virgata – candystick, sugarstick
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, east to Montana, Idaho, and Nevada.
Habitat: Deep humus of coniferous forests at low to middle elevations.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Alnus alnobetula – green alder, mountain alder
Distribution: Widely distributed throughout the mountainous areas on both sides of the Cascades crest in Washington; Alaska to northern California, east to Alberta and the northern Rocky Mountain States.
Habitat: Moist areas, low to high elevations
Origin: Native
Flowers: April-July
Growth Duration: Perennial
• ssp. fruticosa
• ssp. sinuata – mountain alder
Alnus glutinosa – Black alder, European alder
Distribution: Occurring west of the Cascades crest in King County, where escaping from a wetland restoration planting. Great Lakes region east to the Atlantic Coast.
Habitat: Wetlands at low elevation.
Origin: Introduced from Europe
Flowers: March-May
Growth Duration: Perennial
Alnus incana – mountain alder
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, and eastern North America,
Habitat: Moist places, streamsides, and avalanche chutes from low to middle elevations.
Origin: Native
Flowers: March-May
Growth Duration: Perennial
• ssp. tenuifolia – mountain alder
Alnus rhombifolia – white alder
Distribution: Occurring chiefly east of the Cascades crest in Washington; Washington to California and Nevada, east to Idaho.
Habitat: Near streams at low elevations.
Origin: Native
Flowers: January-April
Growth Duration: Perennial
Alnus rubra – 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
Growth Duration: Perennial
Alopecurus aequalis – little foxtail, short-awn foxtail
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Shores, riverbanks, vernal pools, sloughs, wet meadows, and seeps, often submersed.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
• var. aequalis – little foxtail, short-awn foxtail
Alopecurus arundinaceus – creeping meadow-foxtail
Distribution: Occurring east of the Cascades crest in Washington; central British Columbia to Washington, east to the Rocky Mountains and northern Great Plains; also in scattered locations in eastern North America.
Habitat: Alkaline meadows and shores, ditches, shores.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Perennial
Alopecurus carolinianus – tufted meadow-foxtail
Distribution: Occurring on both sides of the Cascades crest in Washington; southern British Columbia to California, east to the Atlantic Coast.
Habitat: Shores, wet meadows, vernal pools, ditches.
Origin: Introduced from central North America?
Flowers: May-July
Growth Duration: Annual
Alopecurus geniculatus – water foxtail
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Atlantic Coast in Canada.
Habitat: Wet places, often in standing water.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Alopecurus myosuroides – slender meadow-foxtail
Distribution: Occurring chiefly east of the Cascades crest in Washington; southwestern British Columbia to California, also in the southern and eastern U.S. and Canadian Great Plains.
Habitat: Margins of cultivated fields, damp roadsides, and vernal pools.
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Annual
Alopecurus pratensis – field meadow-foxtail
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Swampy areas in meadows, in irrigated fields, and along roadsides.
Origin: Introduced from Europe
Flowers: June-July
Growth Duration: Perennial
Alopecurus saccatus – Pacific meadow-foxtail
Distribution: Occurring east of the Cascades crest and in the Columbia River Gorge in Washington; Washington and southwestern Oregon to California.
Habitat: Lowland vernal pools, shores, wet scabland, meadows.
Origin: Native
Flowers: May-June
Growth Duration: Annual
Alyssum alyssoides – small alyssum, pale madwort
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Meadows, forest openings, sagebrush flats, roadsides, fields, and disturbed open areas at low to middle elevations.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Annual, Biennial
Alyssum desertorum – desert alyssum
Distribution: East of the Cascades in Washington; widely distributed throughout central and western North America.
Habitat: Dry, open ground, often where disturbed.
Origin: Introduced from Eurasia
Flowers: May-June
Growth Duration: Annual
Amaranthus albus – white pigweed, tumbleweed
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across much of North America to the Atlantic Coast.
Habitat: Dry, disturbed areas.
Origin: Introduced from tropical America
Flowers: June-September
Growth Duration: Annual
Amaranthus blitoides – matweed, prostrate pigweed
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast; cosmopolitan.
Habitat: Dry, disturbed areas
Origin: Introduced from central United States
Flowers: June - September
Growth Duration: Annual
Amaranthus blitum – livid amaranth, pale amaranth
Distribution: Occurring chiefly west of the Cascades crest in Washington; southern British Columbia to California; also in the southeastern U.S. and eastern North America.
Habitat: Fields, roadsides, wastelots and other disturbed areas.
Origin: Introduced from the tropics
Flowers: May-July
Growth Duration: Annual
Amaranthus californicus – California amaranth
Distribution: Occurring east of the Cascades crest in Washington; eastern Washington to California, east to the Rocky Mountains and Great Plains.
Habitat: Moist, often alkaline flats, lakeshores, and vernal pools.
Origin: Native
Flowers: July-October
Growth Duration: Annual
Amaranthus deflexus – Argentina amaranth
Distribution: Occurring east of the Cascades crest in Washingotn, where known only from Whitman County; Washington to California; also in eastern North America.
Habitat: Open, disturbed areas.
Origin: Introduced from South America
Flowers: July-September
Growth Duration: Annual
Amaranthus hybridus – green amaranth, hybrid amaranth, smooth amaranth, green pigweed, smooth pigweed
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Atlantic Coast.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from eastern North America
Flowers: July-October
Growth Duration: Annual
Amaranthus powellii – green amaranth, Powell's amaranth
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from the southwestern United States and Mexico
Flowers: July-October
Growth Duration: Annual
Amaranthus retroflexus – redroot pigweed, rough pigweed
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from eastern and central North America
Flowers: July-October
Growth Duration: Annual
Amauropelta nevadensis – Nevada marsh fern, Sierra marsh fern, Sierra wood fern
Distribution: Occurring in the Cascades in Washington; Alaska to central Cascades in Washington; also in eastern Asia.
Habitat: Stream banks, moist forest, and springs, lowland to midmontane.
Origin: Native
Growth Duration: Perennial
Ambrosia acanthicarpa – flat spine bur-ragweed, annual bursage, bur ragweed
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to the Great Plains.
Habitat: Sandy soils, dunes, and other well-drained soils in open areas at low to middle elevations, often locally common.
Origin: Native
Flowers: July-October
Growth Duration: Annual
Ambrosia artemisiifolia – annual ragweed, common ragweed
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, pastures, wastelots, and other dry, disturbed, open areas at low elevations.
Origin: Introduced from eastern North America
Flowers: August-October
Growth Duration: Annual
Ambrosia chamissonis – silver beachweed, beach bur, cutleaf beach bur, silver bur-ragweed
Distribution: Occurring west of the Cascades crest along the marine coastline beaches in Washington; British Columbia, south along the coast, to California.
Habitat: Common on sandy beaches above high tide level.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Ambrosia psilostachya – perennial ragweed, western ragweed
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, wastelots, and other disturbed open areas.
Origin: Native
Flowers: July-October
Growth Duration: Perennial
Ambrosia trifida – giant ragweed
Distribution: Occurring chiefly east of the Cascades crest; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, wastelots, and other disturbed sites, often where moist.
Origin: Native
Flowers: July-October
Growth Duration: Annual
Amelanchier alnifolia – saskatoon, serviceberry
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains and Great Plains.
Habitat: Open woods, canyons and hillsides, sea level to subalpine.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Amelanchier utahensis – Utah serviceberry
Distribution: Occurring east of the Cascades crest in Washington; Washington to Baja California, east to the Rocky Mountains and Texas.
Habitat: Rimrock, valleys, gullies and hillsides, from sagebrush desert to mid-elevations in the mountains.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Ammannia coccinea – valley redstem
Distribution: Occurring west of the Cascades crest in Washington, where known only in King County for a restoration site; California east along Mexican border to central and eastern U.S.
Habitat: Restored wetland.
Origin: Introduced from the southern U.S.
Flowers: June-August
Growth Duration: Perennial
Ammannia robusta – western ammania, grand redstem
Distribution: Occurring east of the Cascades crest in Washington chiefly along the Columbia River; British Columbia to California, east to the Great Lakes region and midwestern U.S.
Habitat: Wet places, often where alkaline.
Origin: Native
Flowers: May-June
Growth Duration: Annual
Ammophila arenaria – European beachgrass
Distribution: Occurring west of the Cascades crest in Washington along the marine coast; western British Columbia to California, also in scattered locations along coast of northeastern North America.
Habitat: Sandy beaches and dunes along the coast.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial
• ssp. arenaria – European beachgrass
Ammophila breviligulata – American beachgrass
Distribution: Occurring west of the Cascades crest in Washington along the marine coast; western British Columbia to California; native from Great Lakes region east to the Atlantic Coast.
Habitat: Sandy beaches and dunes along the coast.
Origin: Introduced eastern North America
Flowers: June-August
Growth Duration: Perennial
• ssp. breviligulata – American beachgrass
Amorpha fruticosa – false indigo-bush
Distribution: Occurring chiefly east of the Cascades crest and along the Columbia River in Washington; Washington to California, east across much of North America, including eastern Canada.
Habitat: Disturbed areas, roadsides, wastelots, and often along streams, rivers and other riparian corridors.
Origin: Introduced from eastern North America, where native
Flowers: May-July
Growth Duration: Perennial
Amphiscirpus nevadensis – Nevada bulrush
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to California, east to the Rocky Mountains (but not in Idaho) and northern Great Plains.
Habitat: Alkaline shores, limy fens, and wet meadows; rarely on dredge spoils.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Amsinckia intermedia – fireweed fiddleneck, rancher's fiddleneck
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Baja California, Mexico, east to Idaho, Utah, Arizona, and west Texas.
Habitat: Balds, meadows, prairies, roadsides, and other open areas at low to middle elevations.
Origin: Native
Flowers: April-May
Growth Duration: Annual
Amsinckia lycopsoides – bugloss fiddleneck, tarweed fiddleneck
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Great Plains, also in eastern North America.
Habitat: Roadsides, fields, meadows, grassy slopes, ponderosa pine forest openings, and other open areas from sagebrush desert into the mountains, often associated with some type of disturbance .
Origin: Native
Flowers: April-July
Growth Duration: Annual
Amsinckia menziesii – harvest fiddleneck, rigid fiddleneck, rancher's fireweed
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to California.
Habitat: Open, dry foothills.
Origin: Native
Flowers: April-July
Growth Duration: Annual
Amsinckia retrorsa – harvest fiddleneck, rigid fiddleneck
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Idaho and Utah.
Habitat: Relatively dry and open areas at low to moderate elevations.
Origin: Native
Flowers: April-June
Growth Duration: Annual
Amsinckia spectabilis – seaside amsinckia, seaside fiddleneck
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California.
Habitat: Coastal dunes or sandy bluffs.
Origin: Native
Flowers: May-July
Growth Duration: Annual
• var. spectabilis – seaside amsinckia, seaside fiddleneck
Amsinckia tessellata – bristly amsinckia, bristly fiddleneck, tessellate fiddleneck
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Idaho, south to New Mexico.
Habitat: Roadsides and dry, open slopes and flats, often in disturbed soil.
Origin: Native
Flowers: April-June
Growth Duration: Annual
• var. tessellata – bristly amsinckia, bristly fiddleneck, tessellate fiddleneck
Anaphalis margaritacea – pearly everlasting
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast except for extreme southeastern U.S.
Habitat: Dry to somewhat moist open areas, from low elevations to the subalpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Anchusa azurea – Italian alkanet, Italian bugloss
Distribution: Occurring in scattered localities on both sides of the Cascades crest in Washington; British Columbia to California, scattered localities east to the Atlantic Coast.
Habitat: Disturbed soil.
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Perennial
• var. azurea – Italian alkanet, Italian bugloss
Anchusa officinalis – common alkanet, common bugloss
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east to Rocky Mountains and northern Great Plains, also from the Great Lakes region to northeastern North America.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed, open areas at low elevations.
Origin: Introduced from Mediterranean region
Flowers: May-July
Growth Duration: Biennial, Perennial
Andromeda polifolia – bog rosemary
Distribution: Reported to occur in northern Washington but no specimens seen; Alaska to Idaho, east across Canada, in the Great Lakes region, and in the northeastern U.S.
Habitat: Sphagnum bogs and other acidic wetlands.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
• var. polifolia – bog rosemary
Androsace filiformis – slender-stem rock-jasmine
Distribution: Occurring in the Columbia River Gorge in Washington; south-central Washington to adjacent north-central Oregon, east to Idaho, Montana, Utah and Colorado; also in northern California.
Habitat: Damp to wet meadows, shores, riparian flats and thickets.
Origin: Native
Flowers: June-July
Growth Duration: Annual
Androsace laevigata – smooth douglasia, cliff dwarf-primrose
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to Oregon.
Habitat: Ledges, rocky slopes, moist talus, and ridges, lowland to alpine.
Origin: Native
Flowers: March-August
Growth Duration: Perennial
Androsace nivalis – snow douglasia
Distribution: Occurring east of the Cascades crest in Washington, where endemic to Okanogan, Chelan, Kittitas, and Douglas counties.
Habitat: Sagebrush slopes to alpine ridges and talus, often in serpentine soils.
Origin: Native
Flowers: April-August
Growth Duration: Perennial
Androsace septentrionalis – northern fairy-candelabra, rock-jasmine
Distribution: Occurring in the North Cascades in Washington; Alaska to California; east to the Rocky Mountains, northern Great Plains, and east to Newfoundland; circumpolar.
Habitat: Alpine meadows.
Origin: Native
Flowers: May-August
Growth Duration: Annual
Anemone deltoidea – threeleaf anemone, Columbian windflower
Distribution: Occurring chiefly west of the Cascades crest and east in the Columbia River Gorge in Washington; Washington to California.
Habitat: Dry to moist woodlands at low to middle elevations.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Anemone drummondii – Drummond's anemone, Drummond's windflower
Distribution: Occurring in the Olympic and Cascade Mountains in Washington; Alaska to California, east to Montana and Wyoming.
Habitat: Subalpine to alpine meadows.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• var. drummondii – Drummond's anemone, Drummond's windflower
Anemone lyallii – little mountain anemone, Lyall's anemone, Lyall's windflower
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California.
Habitat: Low elevation prairies to subalpine ridges.
Origin: Native
Flowers: March-July
Growth Duration: Perennial
Anemone multifida – cliff anemone, Pacific anemone
Distribution: Occurring on both sides of the Cascades crest and in the Olympic Mountains in Washington; Alaska to California, east to the northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: From forest openings in the foothills to alpine meadows.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
• var. multifida – cliff anemone, Pacific anemone, Pacific windflower
• var. saxicola – hirsute anemone, hirsute windflower
Anemone occidentalis – mountain pasqueflower, western pasqueflower
Distribution: Occurring in the Olympic and Cascade mountains in Washington; British Columbia to California, east to Alberta, Montana, Idaho, and the Wallowa Mountains of Oregon.
Habitat: Open slopes and meadows from middle elevations to the alpine.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Anemone oregana – Oregon anemone, Oregon windflower
Distribution: Occurring in forested areas on both sides of the Cascades crest in Washington; Washington to northern California.
Habitat: Moist, open woods, low to mid-elevations in the mountains, also in marshes and bogs along the coast.
Origin: Native
Flowers: March-June
Growth Duration: Perennial
• var. felix – Oregon anemone, western wood anemone
• var. oregana – Oregon anemone, western wood anemone
Anemone parviflora – northern anemone, small-flowered anemone, northern windflower
Distribution: Occurring on both sides of the Cascades crest in the North Cascades in Washington; Alaska to northern Washington, east to Montana and Wyoming, in scattered locations in Utah and Colorado, and also east across northern Canada to the Atlantic Coast.
Habitat: Mountain meadows and subalpine stream banks.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Anemone patens – pasqueflower, prairie-crocus
Distribution: Occurring east of the Cascades crest in the Wenatchee Mountains in Washington, where disjunct from the main species range; Alaska, south in the Rocky Mountains to New Mexico, east to the northern Great Plains and the Great Lakes region.
Habitat: Prairies to mountain slopes, mostly on well-drained soil.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
• var. multifida – cliff anemone
Anemone piperi – Piper's anemone, Piper's windflower
Distribution: Occurring east of the Cascades crest in Washington in the far eastern part of the state; Washington to northeast Oregon east to Idaho and western Montana.
Habitat: Shady woods at moderate elevations in the mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Anethum graveolens – dill
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east across much of North America to the Atlantic Coast.
Habitat: Roadsides, fields, wastelots, and other disturbed open areas.
Origin: Introduced from Asia
Flowers: May-August
Growth Duration: Annual
Angelica arguta – Lyall's angelica, sharp-tooth angelica
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta and Utah.
Habitat: Stream banks, wet meadows, marshes and bottomlands, from the foothills and valleys to moderate elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Angelica canbyi – Canby's angelica
Distribution: Occurring chiefly east of the Cascades crest in Washington, though disjunct on the Olympic Peninsula; northern Washington to central and northeastern Oregon.
Habitat: Meadows and forest openings, generally where moist, from low to middle elevations in the mountains.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Angelica genuflexa – kneeling angelica
Distribution: Occurring chiefly west of the Cascades crest and east in the Columbia River Gorge in Washington; Alaska to California, east in British Columbia to the Selkirk Mountains.
Habitat: Stream banks, wet meadows and other moist places, from low to middle elevations in the mountains.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Angelica hendersonii – Henderson's angelica, woolly angelica
Distribution: Occurring on the outer coast in Washington; northwestern Washington to California.
Habitat: Coastal bluffs and sand dunes.
Origin: Native
Flowers: July-August
Growth Duration: Perennial
Angelica lucida – seacoast angelica, sea-watch
Distribution: Occurring west of the Cascades crest in Washington in the coastal counties; Alaska to California, also in eastern North America; Far East Russia.
Habitat: Coastal bluffs, beaches, and estuaries.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Anisocarpus madioides – woodland tarplant, woodland tarweed
Distribution: Occurring west of the Cascades crest in lowland western Washington; Southern British Columbia to southern California.
Habitat: Open woods and woodland edge, and thickets.
Origin: Native
Flowers: May-July
Growth Duration: Biennial, Perennial
Antennaria alpina – alpine pussytoes
Distribution: Occurring in the North Cascades Mountains in Washington; Alaska to Washington, Montana, and Wyoming, east across Canada; circumboreal.
Habitat: Alpine meadows.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Antennaria anaphaloides – tall pussytoes
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia, including southern Vancouver Island, to Oregon, east to Sasketchewan, Montana, Colorado, and Nevada.
Habitat: Grassy hillsides, open woodlands, and ponderosa pine forest openings from the foothills to middle elevations in the mountains.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Antennaria corymbosa – flat topped pussytoes, meadow pussytoes
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to the Rocky Mountains.
Habitat: Streamsides, willow thickets and moist meadows in subalpine and alpine areas.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Antennaria dimorpha – cushion pussytoes, low pussytoes
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and Nebraska.
Habitat: Dry, open places in sagebrush desert to ponderosa pine forest openings, often on lithosol.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Antennaria flagellaris – stoloniferous pussytoes, whip pussytoes
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Idaho, Wyoming, South Dakota, and Nevada.
Habitat: Sagebrush desert to dry, open areas at middle elevations, often in lithosol.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Antennaria geyeri – Geyer's pussytoes, pinewoods pussytoes
Distribution: Occurring east of the Cascades crest in southern Washington; southern Washington to California, east to Nevada.
Habitat: Rocky slopes with ash, sand, or pumice soils, lithosols, and open forest.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
Antennaria howellii – Howell's pussytoes
Distribution: Occurring on both sides of the Cascades crest in Washington; Yukon Territory to California, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Rocky or sandy slopes, dry to moist grasslands, and forest openings at low to middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
• ssp. howellii – Howell's pussytoes
• ssp. neodioica – northern pussytoes
Antennaria lanata – woolly pussytoes
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Wyoming, and Utah.
Habitat: Dry or moist subalpine to alpine meadows, rocky slopes, and ridges.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Antennaria luzuloides – silvery-brown pussytoes, woodrush pussytoes
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and South Dakota.
Habitat: Sagebrush grasslands at low elevations to dry, rocky slopes at middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
• ssp. luzuloides – silvery brown pussytoes, woodrush pussytoes
Antennaria media – alpine pussytoes, Rocky Mountain pussytoes
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains; circumboreal
Habitat: On rocky slopes and ridges, and in talus and pumice, from subalpine to alpine meadows.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Antennaria microphylla – little-leaf pussytoes, rosy pussytoes, white pussytoes
Distribution: Occurring on both sides of the Cascades crest in Washington, but more common east of the crest; Alaska to California, east to the Rocky Mountains and northern Great Plains, Great Lakes region, and eastern Canada.
Habitat: Dry to moist habitats, including meadows, ponderosa pine forest openings, rocky slopes, and floodplains from the lowlands to the alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Antennaria monocephala – pygmy pussytoes, single-headed pussytoes
Distribution: Reported from the North Cascades in Washington; Alaska to British Columbia, east to Alberta, Montana, and Wyoming; also in the Russian Far East.
Habitat: Alpine meadows, ridges, and rocky outcroppings.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Antennaria parvifolia – little-leaf pussytoes, Nuttall's pussytoes
Distribution: Occurring east of the Cascades crest in northeastern Washington; British Columbia to Oregon, east to the Rocky Mountains, Great Plains, and Great Lakes region.
Habitat: Meadows, open forest, gravelly slopes, and sandy flats from the lowlands middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Antennaria pulcherrima – showy pussytoes
Distribution: Occurring east of the Cascades crest in Washington; Alaska to Washington, east to the Rocky Mountains, east across Canada to the Atlantic Coast.
Habitat: Streams, wet thickets and meadows, and peatlands from middle elevations to the alpine.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Antennaria pulvinata – white pussytoes
Distribution: Occurring on both sides of the Cascades crest in Washington, but more common east of the crest; Yukon Territory to northern Washington, east to Alberta and Montana.
Habitat: Alpine areas where rocky.
Origin: Native
Flowers: July-August
Growth Duration: Perennial
Antennaria racemosa – Hooker's pussytoes, raceme pussytoes
Distribution: Widely distributed in mountainous areas on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, and Wyoming.
Habitat: Dry to damp rocky slopes, forest openings, and ledges from low to elevations to the alpine.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Antennaria stenophylla – narrowleaved pussytoes
Distribution: Occurring east of the Cascades crest in Washington; Washington to Nevada, east to central Idaho.
Habitat: Rocky slopes, flats, lithosol areas, and dry grasslands in sagebrush desert.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Antennaria umbrinella – brown-bract pussytoes, umber pussytoes
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to Saskatchewan, Montana, Wyoming, and Colorado.
Habitat: Forest openings at middle elevations to subalpine meadows.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Anthemis arvensis – corn chamomile, field chamomile
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, east to the northern Great Plains in the U.S, widespread from the midwestern U.S. to eastern North America.
Habitat: Roadsides, fields, wastelots, and other disturbed open areas generally at low elevations.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Annual
Anthemis cotula – mayweed chamomile, stinking chamomile, dogfennel
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed areas generally at low elevations.
Origin: Introduced from Europe
Flowers: May-October
Growth Duration: Annual
Anthoxanthum aristatum – annual vernalgrass
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California; occurring throughout most of central and eastern half of North America.
Habitat: Meadows, grasslands, forest openings, and other disturbed, open areas at low to moderate elevations.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Annual
• ssp. aristatum – small sweet vernal grass
Anthoxanthum odoratum – sweet vernalgrass
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, southern Great Plains, and eastern North America.
Habitat: Roadsides, fields, meadows, prairies, balds, lawns, and other disturbed open areas at low elevations.
Origin: Introduced from Europe
Flowers: April-July
Growth Duration: Perennial
Anthriscus caucalis – burr chervil
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across much of the United States and parts of Canada to the Atlantic Coast.
Habitat: Roadsides, forest edges, wastelots, and other disturbed areas where often seasonally moist.
Origin: Introduced from Eurasia
Flowers: April-July
Growth Duration: Annual
Anthriscus sylvestris – wild chervil
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon, east to Idaho, also in eastern North America and Greenland.
Habitat: Roadsides, fields, forest edge, wastelots, and other disturbed areas where seasonally moist.
Origin: Introduced from Eurasia
Flowers: May-August
Growth Duration: Annual
Anticlea elegans – glaucous death-camas
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon and Nevada, east across much of North America to the Atlantic Coast.
Habitat: Meadow, open forests and rocky slopes, mid- to high elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Anticlea occidentalis – bronze bells, mission bells, western featherbells
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Idaho, and Montana.
Habitat: Wet cliffs, moist meadows and scree, mostly at middle to high elevations, but down to near sea level in the Olympic Peninsula and the Columbia River Gorge.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Antirrhinum majus – garden snapdragon, greater snapdragon
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California, east to Idaho; also in eastern North America.
Habitat: Disturbed areas in urban settings.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Annual
Apera interrupta – dense silky-bent
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains; also in the central U.S., Great Lakes region, and northeastern U.S.
Habitat: Dry wasteland and other disturbed areas in shrub-steppe and open coniferous forests.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Annual
Aphanes arvensis – western lady's-mantle, field parsley-piert
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; southern British Columbia to California, reported in Idaho, also along Atlantic Coast in the U.S.
Habitat: Ledges, often limy, sandy shores, hot springs, and other disturbed open ground at low elevations.
Origin: Introduced from Eurasia and northern Africa
Flowers: April-May
Growth Duration: Annual
Aphanes australis – small-fruited parsley-piert
Distribution: Occurring west of the Cascades crest in Washington; southwestern British Columbia to northwestern Oregon, also in southeastern U.S.
Habitat: Openings, shores, lawns, and other disturbed areas at low elevations.
Origin: Introduced from Europe
Flowers: March-May
Growth Duration: Perennial
Aphanes occidentalis – western parsley-piert
Distribution: Occurring west of the Cascades crest in lowland western Washington and east in the Columbia River Gorge; southern British Columbia to California.
Habitat: Vernally damp grasslands, balds, fields, ledges, rocky slopes, open forest, shores, and beaches at low elevations.
Origin: Native
Flowers: April-June
Growth Duration: Annual
Aphyllon californicum – California broomrape
Distribution: Occurring west of the Cascades crest and east in the Columbia River Gorge in Washington; southwestern British Columbia to Baja California, also east of the Cascades crest in Oregon.
Habitat: Coastal and sub-coastal, or in meadows inland, parasitic on Asteraceae but not on Artemisia tridentata.
Origin: Native
Flowers: April-June
Growth Duration: Annual, Perennial
• ssp. californicum – California broomrape
• ssp. grayanum – Gray's California broomrape
Aphyllon corymbosum – flat-topped broomrape
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and the Canadian Great Plains.
Habitat: Sagebrush desert areas, parasitic mainly on Artemisia tridentata.
Origin: Native
Flowers: May-July
Growth Duration: Annual, Perennial
• ssp. corymbosum – flat-topped broomrape
• ssp. mutabile – flat-topped broomrape
Aphyllon fasciculatum – clustered broomrape
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to the Great Plains and the Great Lakes region.
Habitat: Dry, open places, valleys to montane, parasitic exclusively on Artemisia.
Origin: Native
Flowers: May-July
Growth Duration: Annual
Aphyllon franciscanum – clustered broomrape
Distribution: Occurring on both sides of the Cascades crest in Washington; southwestern British Columbia to Baja California, east to the Rocky Mountains and Texas.
Habitat: Open areas from low to middle elevations. Parasitic on Eriogonum, Eriophyllum lanatum, and Phacelia, also other taxa outside of Washington, but never Artemisia.
Origin: Native
Flowers: April-August
Growth Duration: Perennial
Aphyllon ludovicianum – Louisiana broomrape, Suksdorf's broomrape
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon, east to the Rocky Mountains and Great Plains of Canada and the U.S.
Habitat: Dry, open, often sandy areas, parasitic on Artemisia, Chrysopsis, and other woody Asteraceae.
Origin: Native
Flowers: May-July
Growth Duration: Annual
Aphyllon pinorum – pine broomrape, pinewoods broomrape
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to California, east to northern Idaho, Nevada and New Mexico.
Habitat: Montane coniferous forest, parasitic on Holodiscus.
Origin: Native
Flowers: June-August
Growth Duration: Annual
Aphyllon purpureum
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Alberta and the Rocky Mountains.
Habitat: From lowland to montane, often where open and seasonally moist, parasitic mainly on Asteraceae, Saxifragaceae, and Sedum.
Origin: Native
Flowers: April-August
Growth Duration: Annual
Apium graveolens – celery
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; Washington to California, east to Idaho, Utah, and Nevada, east across the southern U.S. to eastern North America.
Habitat: Disturbed ground, usually where moist, where escaped from nearby cultivation.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial
• var. dulce
Apocynum androsaemifolium – flytrap dogbane, spreading dogbane
Distribution: Occurring on both sides of the Cascades crest in Washington, but more common east of the crest; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Common in forest openings, thickets, hillsides, roadsides, meadows and other open areas with dry soil, from low elevations to nearly subalpine areas.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Apocynum cannabinum – clasping-leaved dogbane, common dogbane, hemp dogbane
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Stream banks, moist hillsides and forest openings, fields, and wastelots at low to middle elevations.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Apocynum ×floribundum – western dogbane
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Dry, open areas, gen in valleys and at lower elevations in the mountains.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Aquilegia flavescens – yellow columbine
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon, east to the Rocky Mountains.
Habitat: Moist mountain meadows and talus to alpine slopes
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Aquilegia formosa – red columbine, Sitka columbine
Distribution: Widely distributed on both sides of the Cascades crest throughout Washington; Alaska to California, coastal and inland to Alberta and Wyoming.
Habitat: Open woods, from the lowlands to moderate elevations in the mountains.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
• var. formosa – red columbine, Sitka columbine, western columbine
Aquilegia ×miniana – hybrid columbine
Distribution: Occurring east of the Cascades crest in central Washington; British Columbia to Washington, east to Idaho.
Habitat: Moist mountain meadows and talus to alpine slopes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Aquilegia vulgaris – European Columbine
Distribution: Introduced as a garden flower, occasionally escaping.
Habitat: Disturbed soil near gardens.
Origin: Introduced
Flowers: May-July
Growth Duration: Perennial
Arabidopsis kamchatica – kamchatka rockcress, lyre-leaved rockcress, western rockcress
Distribution: Occurring west of the Cascades crest in northwestern Washington; Alaska to Washington, east to Northwest Territory and Sasketchewan.
Habitat: Subalpine and alpine scree and talus slopes.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Arabidopsis thaliana – mouse-ear cress, thalecress
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across most of North America.
Habitat: Disturbed areas, particularly near cities and towns.
Origin: Introduced from Eurasia
Flowers: March-May
Growth Duration: Annual
Arabis caucasica – mountain rockcress
Distribution: Known only from San Juan County in Washington; Yukon Territory to northwestern Washington.
Habitat: Open, disturbed areas at low elevation, often near where cultivated.
Origin: Introduced
Flowers: May-June
Growth Duration: Perennial
Arabis crucisetosa – crosshaired rockcress
Distribution: Occurring in the southeastern corner of Washington; Snake River canyon, Asotin County, Washington, east to west-central Idaho.
Habitat: Wet banks to moist soil or coniferous woods.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Arabis eschscholtziana – hairy rockcress, Pacific coast rockcress
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the northern Rocky Mountains.
Habitat: Open areas, often in waste places, from sea level to mid-elevations in the mountains.
Origin: Native
Flowers: April-July
Growth Duration: Annual, Biennial, Perennial
Arabis furcata – Cascade rockcress, Columbia Gorge rockcress, fork-haired rockcress
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to Oregon.
Habitat: Open slopes, meadows, and ridgelines in alpine and subalpine areas, and exposed areas in the Columbia River Gorge.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Arabis nuttallii – Nuttall's rockcress
Distribution: Occurring east of the Cascades crest in Washington; eastern British Columbia to eastern Washington, east to Alberta, Montana, Wyoming, and Utah.
Habitat: Moist flats, often sheltered by shrubs, from the foothills to middle elevations in the mountains.
Origin: Native
Flowers: April-August
Growth Duration: Perennial
Arabis olympica – Olympics rockcress
Distribution: Occurring west of the Cascades crest in Washington, where endemic to the Olympic Mountains.
Habitat: Talus slopes and subalpine meadows.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Aralia nudicaulis – wild sarsaparilla
Distribution: Occurring east of the Cascades crest in northeastern Washington; Yukon Territory to northeastern Washington, east to and south in Rocky Mountains, east to eastern North America.
Habitat: Moist, shaded soil.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Arbutus menziesii – Pacific madrona, Pacific madrone
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to California.
Habitat: Chiefly in drier, often rocky areas at low elevations.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Arbutus unedo – strawberry tree
Distribution: Occurring west of the Cascades crest in Washington; currently known as escaped from cultivation in Washington.
Habitat: Disturbed, open to partially sunny areas in and around urban areas, where escaped from cultivation.
Origin: Introduced
Flowers: April-September
Growth Duration: Perennial
Arceuthobium abietinum – white fir dwarf mistletoe
Distribution: Occurring on both sides of the Cascades crest in southern Washington; southern Washington to California, east to Utah, Nevada, and Arizona.
Habitat: Primarily on Abies grandis and A. concolor in our area, rarely on adj A. amabilis and Pinus spp. in Oregon Cascades.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arceuthobium americanum – lodgepole pine dwarf mistletoe
Distribution: Occurring chiefly east of the Cascades rest in Washington; southern British Columbia to California, east to the Rocky Mountains.
Habitat: Parasitic on Pinus, usually on Pinus contorta.
Origin: Native
Flowers: April- June
Growth Duration: Perennial
Arceuthobium campylopodum – western dwarf mistletoe
Distribution: Occurring chiefly east of the Cascades crest in Washington; eastern Washington to California, east to northern and central Idaho.
Habitat: Parasitic primarily on Pinus ponderosa, occasionally on adjacent P. contorta vars. latifolia and murrayana and rarely on P. lambertiana, not known on Tsuga or Larix;
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Arceuthobium douglasii – Douglas-fir dwarf mistletoe
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Parasitic primarily on Pseudotsuga menziesii, rarely on adjacent Abies and Picea.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Arceuthobium laricis – larch dwarf mistletoe
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon, east to Idaho and Montana.
Habitat: Primarily on Larix occidentalis and Tsuga mertensiana, occasionally on adjacent Pinus contorta, P. ponderosa, and Abies lasiocarpa, not on Tsuga heterophylla.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arceuthobium tsugense – hemlock dwarf mistletoe
Distribution: Occurring west of the Cascades crest in Washington; southeastern Alaska to California.
Habitat: Parasitic primarily on Tsuga heterophylla, and also Abies amabilis, A. procera, and occasionally adjacent A. grandis.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• ssp. contortae – hemlock dwarf mistletoe
• ssp. tsugense – hemlock dwarf mistletoe
Arcteranthis cooleyae – Cooley's buttercup
Distribution: Occurring west of the Cascades crest in Washington; Alaska to Washington.
Habitat: Damp slopes and rocky crevices at high elevations, blossoming as snow recedes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arctium lappa – great burdock, greater burdock
Distribution: Known from a few scattered locations in Washington; British Columbia to California, in Montana, east from California to Colorado and Arizona, also across Canadian Great Plains to Great Lakes region and northeastern North America.
Habitat: Roadsides, ditches, forest openings and edge, wastelots, and other disturbed areas generally at low elevations.
Origin: Introduced from Eurasia
Flowers: August-October
Growth Duration: Biennial, Perennial
Arctium minus – common burdock, lesser burdock
Distribution: Occurring on both sides of the Cascades crest in Washington; British to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, meadows, wastelots, and other disturbed open areas at low to middle elevations.
Origin: Introduced
Flowers: July-October
Growth Duration: Biennial
Arctostaphylos columbiana – bristly manzanita
Distribution: Occurring chiefly west of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to California.
Habitat: Dry forest openings and rocky slopes, mostly at low elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Arctostaphylos ×media – medium manzanita
Distribution: Occurring west of the Cascades crest in Washington, chiefly on the east side of the Olympic Peninsula. Washington to Oregon.
Habitat: Rocky balds and forest openings from low to moderate elevations.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Arctostaphylos nevadensis – pinemat manzanita
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to California, east to Nevada.
Habitat: Dry forest edge and openings from middle elevations in the mountains to the subalpine.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
• ssp. nevadensis – pinemat manzanita
Arctostaphylos nevadensis × Arctostaphylos patula
Origin: Native
Arctostaphylos patula – green-leaf manzanita
Distribution: Occurring east of the Cascades crest in Washington, where disjunct in Chelan County, otherwise in Klickitat County only; Washington to California, east to Montana and Colorado.
Habitat: Chaparral and dry, open forests.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
• var. patula – green-leaf manzanita
Arctostaphylos uva-ursi – red bearberry, kinnikinnick
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California east to the Rocky Mountains, also further east across the northern U.S. and Canada to the Atlantic Coast; circumboreal.
Habitat: Coastal bluffs and prairies, rocky balds, dry subalpine meadows, and dry coniferous forest openings.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Arenaria paludicola – marsh sandwort
Distribution: Presumed extirpated from Washington; historically west of the Cascades crest along the coast. California to Central America.
Habitat: Swampy places, mostly along coast.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Arenaria serpyllifolia – thyme-leaf sandwort
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Dry to moist, barren to wooded places.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Annual
• var. serpyllifolia – thyme-leaf sandwort
Aristida purpurea – threeawn
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to central Canada and the central U.S.
Habitat: Desert plains, grasslands, and pondersoa pine forests.
Origin: Native
Flowers: June-July
Growth Duration: Annual, Perennial
• var. longiseta – red threeawn
Armeria arenaria – Jersey thrift
Distribution: Occurring west of the Cascades crest in Washington; not known from elsewhere in North America.
Habitat: Roadsides, fields, ditches, and other disturbed open areas at low elevations.
Origin: Introduced from Europe
Flowers: April-July
Growth Duration: Perennial
Armeria maritima – sea-pink, thrift
Distribution: Occurring west of the Cascades crest in Washington, chiefly in the coastal counties; Alaska to California, east across Canada to northeastern North America; Greenland and Europe.
Habitat: Along beaches, coastal bluffs and balds, occasionally inland in prairies.
Origin: Native
Flowers: March-July
Growth Duration: Perennial
• ssp. californica – sea-pink, thrift
• ssp. maritima – sea-pink, thrift
Armoracia rusticana – horseradish
Distribution: Occurring in scattered locations east of the Cascades crest in Washington; Alaska to California, east across the U.S. and Canada to the Atlantic Coast.
Habitat: Disturbed areas including fields, roadsides and wastelots.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Perennial
Arnica chamissonis – leafy arnica, meadow arnica, narrowleaf arnica, silvery arnica, leafy leapordbane
Distribution: Occurring both sides of the Cascades, including the northeastern corner of Washington; Alaska to California, east to the Rocky Mountains, east across Canada to the Atlantic Coast.
Habitat: Meadows and wet places from middle elevations to the subalpine.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Arnica cordifolia – heart-leaf arnica, heart-leaf leopardbane
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, and the Great Lakes region.
Habitat: Light forest understory, openings, and edge, from low elevations to the subalpine.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Arnica discoidea – rayless arnica, rayless leopardbane
Distribution: Occurring in the Cascades Mountains of Klickitat and Skamania counties in Washington; Washington to California, east to Nevada.
Habitat: Forest openings from middle elevations to the subalpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica fulgens – hillside arnica, orange arnica, shining leopardbane
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Meadows and open slopes from the foothills to middle elevations in the mountains
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Arnica gracilis – slender arnica, slender leopardbane
Distribution: Occurring on both sides of the Cascades crest in the mountainous areas in Washington; British Columbia to Oregon, east to Alberta, Montana, Wyoming, and Utah.
Habitat: Dry, rocky slopes and meadows, from the subalpine to alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica lanceolata – clasping arnica, stream bank arnica
Distribution: Occurring on both sides of the Cascades crest in Washington, including the Olympic Mountains and the northeastern region; Alaska to California, east to the Rocky Mountains, also in northeastern North America.
Habitat: Streambanks, moist woods and meadows from middle elevations to the subalpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• ssp. prima – clasping arnica, streambank arnica, streambank leopardbane
Arnica latifolia – broad-leaved arnica, mountain arnica, daffodil leopardbane
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains.
Habitat: Common in forest openings and meadows, and open, rocky areas from middle to high elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica longifolia – longleaf arnica, seep spring arnica, spear-leaf leopardbane
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Rocky soil in seeps or springs, cliffs, or riverbanks, from middle elevations to the alpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Arnica mollis – cordilleran arnica, hairy arnica, cordilleran leopardbane
Distribution: Occurring on both sides of the Cascades crest and in the Olympic Mountains in Washington; Alaska to California, east to the Rocky Mountains.
Habitat: Moist meadows from middle elevations to the alpine.
Origin: Native
Flowers: June-September
Growth Duration: Perennial
Arnica nevadensis – Nevada arnica, Sierra arnica, Sierran leopardbane
Distribution: Occurring in the Cascades and Olympic mountains in Washington; Washington to California, east to Nevada.
Habitat: Open, rocky slopes and forest openings in the subalpine and alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica ovata – sticky arnica, sticky-leaf arnica
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Montana and Utah.
Habitat: Rocky places from middle elevations to the subalpine and alpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Arnica parryi – Parry's arnica
Distribution: Occurring on both sides of the Cascades crest in Washington; Yukon Territory to California, east to the Rocky Mountains.
Habitat: Open woods and meadows, from middle elevations to the alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica rydbergii – Rydberg's arnica, subalpine arnica, subalpine leopardbane
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to northern California, east to Alberta and Colorado.
Habitat: Dry meadows and open slopes at high elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Arnica sororia – bunch arnica, twin arnica, twin leopardbane
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, and Wyoming.
Habitat: From low elevation prairies and grasslands to coniferous forest openings at middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Aronia melanocarpa – black chokeberry
Origin: Introduced
Arrhenatherum elatius – bulbous oatgrass
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Meadows, balds, pastures, fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Perennial
Artemisia absinthium – absinthe, old-man, wormwood
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across much of North America to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed open areas.
Origin: Introduced from Eurasia
Flowers: July-September
Growth Duration: Perennial
Artemisia annua – sweet Annie, sweet sagewort, annual wormwood
Distribution: Occurring in scattered locations east of the Cascades crest and in the Columbia River Gorge in Washington; Washington to California, east across most of North America to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed open places.
Origin: Introduced from Eurasia
Flowers: August-October
Growth Duration: Annual
Artemisia arbuscula – dwarf sagebrush, low sagebrush
Distribution: Occurring east of the Cascades crest in Washington; central Washington to California, east to the Rocky Mountains.
Habitat: Open, dry plains and hills in sagebrush desert.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
• ssp. arbuscula – little sagebrush, low sagebrush
Artemisia biennis – biennial wormwood
Distribution: Occurring on both sides of the Cascades crest and in the Columbia River Gorge in Washington; Alaska to California, east across most of North America to the Atlantic Coast, where considered introduced.
Habitat: Roadsides, fields, irrigation ditches, streambanks, and other disturbed open areas, especially in sandy soil.
Origin: Native
Flowers: August-October
Growth Duration: Annual, Biennial
Artemisia campestris – Pacific sagewort, northern wormwood
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast; also in Eurasia.
Habitat: Open places, often in sandy or rocky soil, from low elevations to alpine.
Origin: Native
Flowers: July-September
Growth Duration: Biennial, Perennial
• var. borealis – northern wormwood
• var. scouleriana – Pacific sagewort, Scouler's wormwood
• var. wormskioldii – Columbia Islands sagewort, Wormskiold's wormwood sagewort
Artemisia cana – hoary sagebrush, silver sagebrush
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Meadows and forest openings from low to middle elevations in the mountains.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
• ssp. bolanderi – Bolander's hairy sagebrush
Artemisia douglasiana – Douglas's mugwort, Douglas's sagewort, Douglas's wormwood
Distribution: Occurring on both sides of the Cascades crest and in the Columbia River Gorge in Washington; Washington to California, east to Nevada.
Habitat: Mostly along stream banks and river bottoms.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Artemisia dracunculus – dragon sagewort, tarragon, dragon wormwood
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to the Great Plains and Great Lakes region.
Habitat: Sagebrush desert to ponderosa pine forest openings at middle elevations.
Origin: Native
Flowers: July-October
Growth Duration: Perennial
Artemisia frigida – prairie sagebrush, prairie sagewort
Distribution: Occurring east of the Cascades crest in Washington; Alaska to Washington, east to the Great Plains, Great Lakes region, and northeastern North America.
Habitat: Dry, open sagebrush plains and foothills.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Artemisia furcata – three-forked mugwort, forked wormwood
Distribution: Occurring in the Cascades and Olympic Mountains of Washington; Alaska to Washington, east to Northwest Territories, Alberta, and Nunavut.
Habitat: Open, rocky ledges and talus slopes in the subalpine and alpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Artemisia ludoviciana – western mugwort, prairie sage
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Meadows and open slopes, from the lowlands to the alpine.
Origin: Native
Flowers: June-October
Growth Duration: Perennial
• ssp. candicans – gray sagewort
• ssp. incompta – intermediate sagewort, mountain wormwood
• ssp. lindleyana – Lindley's western mugwort, Lindley's prairie sage
• ssp. ludoviciana – western mugwort, Louisiana sagewort, silver wormwood
Artemisia michauxiana – Michaux's mugwort, lemon sagewort, Michaux's wormwood
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta and Wyoming.
Habitat: Rocky places in the mountains at rather high elevations.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
Artemisia norvegica – mountain sagewort, boreal wormwood
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska south to California, east to the Rocky Mountains.
Habitat: Subalpine and alpine areas, typically where moist.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
• ssp. saxatilis – mountain sagewort
Artemisia rigida – scabland sagebrush, stiff sagebrush
Distribution: Occurring east of the Cascades crest in Washington; Washington to Oregon, east to Idaho and Montana.
Habitat: Dry, rocky places from the plains and foothills to moderate elevations in the mountains.
Origin: Native
Flowers: September-October
Growth Duration: Perennial
Artemisia spiciformis – snowfield sagebrush, spiked sagebrush
Distribution: Occurring east of the Cascades crest in Washington; central Washington to California, east to southwestern Montana, Wyoming, and Colorado.
Habitat: Cool, moist slopes, from middle elevations to subalpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Artemisia stelleriana – dusty miller, old-woman, beach wormwood, Steller's wormwood
Distribution: Occurring west of the Cascades crest along the northeastern coast of the Olympic Peninsula in Washington; native to Alaska, also occurring from the Great Lakes region east to northeastern North America.
Habitat: Coastal dunes and beaches in developed coastal areas, where escaping from cultivation.
Origin: Introduced
Flowers: May-September
Growth Duration: Perennial
Artemisia suksdorfii – coastal mugwort, Suksdorf's sagewort, coastal wormwood
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California.
Habitat: Bluffs, beaches, rocky areas, and riverbanks, especially near the coast.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Artemisia tilesii – Aleutian mugwort, Cascade wormwood
Distribution: Occurring in the Olympic and Cascade Mountains of Washington; Alaska to Oregon, east to Montana, and east across Canada to Quebec.
Habitat: Open rocky or gravelly, wet or dry sites, from middle elevations to the alpine, descending to sea level northward.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Artemisia tridentata – big sagebrush
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Dry plains and foothills to the subalpine, but not in lithosol or alkaline soil.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
• ssp. tridentata – big sagebrush
• ssp. vaseyana – mountain big sagebrush, Vasey sagebrush
• ssp. wyomingensis – Wyoming sagebrush
Artemisia tripartita – cut-leaf sagebrush, threetip sagebrush
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon and Nevada, east to Idaho and Wyoming.
Habitat: Sagebrush desert and grasslands.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
• ssp. tripartita – cutleaf sagebrush, threetip sagebrush
Artemisia vulgaris – mugwort, lobed wormwood
Distribution: Occurring on both sides of the Cascades crest and in the Columbia River Gorge in Washington; Alaska to Oregon, east to Montana, east across Canada to the Great Lakes region and eastern North America.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed, open areas.
Origin: Introduced from Eurasia
Flowers: August-October
Growth Duration: Perennial
Arum italicum – orange candleflower, Italian lords and ladies
Distribution: Occurring west of the Cascades crest in lowland western Washington; southwestern British Columbia to California; also in scattered location in central and eastern U.S.
Habitat: Forest understory and disturbed locations near urbanized areas.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial
• ssp. italicum – Italian arum, Italian lords and ladies
Aruncus dioicus – sylvan goatsbeard
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to Alberta, also in the eastern half of North America.
Habitat: Moist forest and forest edge from low elevations to the subalpine.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
• var. acuminatus – Sylvan goatsbeard
Asarum caudatum – wild ginger
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Idaho and Montana.
Habitat: Moist, shady woods at low to mid-elevations in the mountains.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Asclepias cryptoceras – Humboldt milkweed, pallid milkweed
Distribution: Occurring east of the Cascades crest in southeastern Washington; southeastern Washington to California, east to Idaho, Wyoming, and Colorado.
Habitat: Gravelly to heavy clay soil in the foothills and lower mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Asclepias fascicularis – Mexican whorled milkweed, narrow-leaf milkweed
Distribution: Occurring east of the Cascades crest in Washington; northeastern Washington to Baja California, Mexico, east to Idaho, Utah, and Arizona.
Habitat: Sagebrush desert, usually along vernal stream beds.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Asclepias incarnata – swamp milkweed
Distribution: Known from Okanogan County in Washington; Washington, also in Idaho, east across North America to Atlantic Coast.
Habitat: Riparian zone, including standing water
Origin: Introduced?
Flowers: August
Growth Duration: Perennial
Asclepias speciosa – showy milkweed
Distribution: Occurring east of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to Mexico, east to the Great Plains and Great Lakes region.
Habitat: Riparian corridors, irrigation ditches, roadsides, and other at least seasonally wet areas at low elevations, often in loam soils.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Askellia pygmaea – low hawksbeard
Distribution: Occurring in the Olympic and Cascades mountains in Washington; Alaska to California, east to Nunavut and Colorado, also in northeastern Canada; Asia.
Habitat: Talus, scree, moraines, sandy or gravelly slopes, subalpine to alpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
Asparagus officinalis – asparagus
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Atlantic Coast.
Habitat: Garden escape, often of roadsides, fields, wastelots, and other disturbed areas..
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Perennial
Asperugo procumbens – catchweed, madwort
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to the Great Plains, also in eastern North America.
Habitat: Roadsides, fields, irrigation ditches, and other disturbed open areas where moist.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Annual
Aspidotis densa – Oregon , Indian's dream, podfern
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Idaho, Montana, South Dakota, western Wyoming, and northern Utah; disjunct in Quebec.
Habitat: Cliff crevices and moist, rocky slopes, foothills to near timberline, often on serpentine
Origin: Native
Growth Duration: Perennial
Asplenium trichomanes – maidenhair spleenwort
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, also in southern Rocky Mountain states and in central U.S. and eastern North America.
Habitat: Cliff crevices, rocky outcroppings, and talus slopes, generally where moist.
Origin: Native
Spores: May-September
Growth Duration: Perennial
• ssp. quadrivalens – maidenhair spleenwort
• ssp. trichomanes – maidenhair spleenwort
Asplenium viride – green spleenwort
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across northern North America to New England and the Canadian Maritimes; circumboreal.
Habitat: Cliff crevices, especially on limestone, often near or above timberline.
Origin: Native
Growth Duration: Perennial
Astragalus agrestis – cock's-head, field milk vetch, purple milk vetch
Distribution: Occurring east of the Cascades crest in Washington; Yukon Territory to California, east across North America to Canada's Atlantic Coast.
Habitat: Moist spots in sagebrush plains, and mountain meadows to alpine slopes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
Astragalus alpinus – alpine milk-vetch, purple milk-vetch
Distribution: Occurring east of the Cascades crest in the north-central region of Washington; Alaska to northeastern Oregon and northeastern Nevada, east to the Rocky Mountains; circumboreal.
Habitat: Open slopes and rocky areas from upper montane to alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• var. alpinus – alpine milk-vetch
Astragalus arrectus – hanging pod milk-vetch, Palouse milk-vetch
Distribution: Occurring east of the Cascades crest in Washington, where known from Lincoln and Whitman; eastern Washington to adjacent Idaho.
Habitat: Sagebrush flats to open ponderosa pine forest.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus arthuri – Arthur's milk-vetch
Distribution: Occurring east of the Cascades crest, where known only from Asotin County in Washington; southeastern Washington to northeastern Oregon and adjacent west-central Idaho.
Habitat: Grassy hills and rocky meadows, often on basalt.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus arthurii
Origin: Native
Growth Duration: Perennial
Astragalus asotinensis – Asotin milk-vetch
Distribution: Occurring east of the Cascades crest, where known only from Asotin County in Washington; Endemic to Snake River Canyon of southeastern Washington and adjacent Idaho.
Habitat: Grassy slopes in shrub-steppe at low to moderate elevations.
Origin: Native
Flowers: March-May
Growth Duration: Perennial
Astragalus australis – Indian milk-vetch, subarctic milk-vetch
Distribution: Occurring west of the Cascades crest in the Olympic Mountains in Washington; Alaska to the Olympic mountains, northeastern Oregon, Nevada, Utah, and Colorado, east to the Great Plains and eastern Canada.
Habitat: Foothill bluffs and riverbanks to subalpine and alpine ridges and scree.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• var. cottonii – Cotton's milk-vetch, Cotton's milkvetch
Astragalus beckwithii – Beckwith's milk-vetch
Distribution: Occurring east of the Cascades crest in the southeastern region of Washington; southeastern Washington to northeastern Nevada, east to western Idaho along the Snake River drainage, also disjunct in Kamloops, British Columbia.
Habitat: Sagebrush desert to dry hillsides.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
• var. weiserensis – Beckwith's milk-vetch
Astragalus canadensis – Canada milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Prairies, stream banks, ditches, ponderosa pine forest openings, and seasonally moist alkaline flats in sagebrush.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
• var. brevidens – Canada milk-vetch
• var. canadensis – Canada milk-vetch
• var. mortonii – Morton's Canadian milk-vetch
Astragalus caricinus – buckwheat milk-vetch
Distribution: Occurring east of the Cascades crest in the south-central Washington; Washington south along the Snake River corridor to Oregon and southwestern Idaho.
Habitat: Grasslands, dry and sandy slopes in sagebrush habitat.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Astragalus cicer – chickpea milk-vetch
Distribution: Occurring In scattered locations chiefly east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountain states and in eastern North America.
Habitat: Roadsides, fields, dry slopes, and other disturbed areas, often where moist or wet.
Origin: Introduced from Europe
Flowers: July-August
Growth Duration: Perennial
Astragalus collinus – hill milk-vetch, hillside milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to Oregon, east to west-central Idaho along the Snake and Clearwater Rivers.
Habitat: Basaltic grasslands and sagebrush deserts.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
• var. collinus – hillside milk-vetch
Astragalus columbianus – Columbian milk-vetch
Distribution: Occurring east of the Cascades crest in Washington, where endemic to south-central Washington.
Habitat: Dry, open areas in shrub-steppe.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Astragalus conjunctus – basalt milk-vetch, stiff milk-vetch
Distribution: Occurring east of the Cascades crest from south-central to southeastern Washington; Washington to southeast Oregon and adjacent southwestern Idaho.
Habitat: Sagebrush grasslands to brushy slopes and ponderosa pine forest openings.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
• var. rickardii – stiff milk-vetch
Astragalus cusickii – Cusick's milk-vetch
Distribution: Occurring east of the Cascades crest in southeastern Washington; Washington to east-central Oregon, east to central Idaho.
Habitat: Sagebrush plains to grassy or rocky slopes, often on talus.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
• var. cusickii – Cusick's milk-vetch
Astragalus diaphanus – John Day milk-vetch, transparent milk-vetch
Distribution: Known historically from Klickitat County in Washington, but now thought to be extirpated; Klickitat County, Washington to Wheeler and Grant counties in Oregon.
Habitat: Gravel bars, alluvial slopes, and in thin gravelly soil overlying basaltic rock.
Origin: Native
Flowers: May-June
Growth Duration: Annual, Biennial
Astragalus falcatus – Russian milk-vetch, sickle milk-vetch
Distribution: Occurring east of the Cascades crest, where known from Whitman County in Washington; British Columbia to Washington and Montana, also in a few scattered locations across North America.
Habitat: Disturbed, open areas.
Origin: Introduced from Eurasia
Flowers: July
Growth Duration: Perennial
Astragalus filipes – basalt milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to northeast California, east to Nevada and Idaho.
Habitat: Sagebrush plains and lower foothills.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus geyeri – Geyer's milk-vetch
Distribution: Occurring east of the Cascades crest in south-central Washington; disjunct in British Columbia and along Columbia River of Washington and north-central Oregon; otherwise southeastern Oregon to Nevada and California, east to Montana, Wyoming, and Utah.
Habitat: Sandy desert areas, especially on dunes.
Origin: Native
Flowers: June-July
Growth Duration: Annual, Biennial
• var. geyeri – Geyer's milk-vetch
Astragalus hoodianus – Hood River milk-vetch
Distribution: Occurring in the east end of the Columbia River Gorge in Klickitat County in Washington; Klickitat County, Washington to Hood River and Wasco counties in Oregon.
Habitat: Dry, open areas in sagebrush and grasslands.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus howellii – Howell's milk-vetch
Distribution: Occurring east of the Cascades crest in the southeastern corner of Washington; southeastern Washington to north-central Oregon.
Habitat: Stony hillsides among sagebrush and bunchgrass, often over basalt.
Origin: Native
Flowers: Arpil-June
Growth Duration: Perennial
Astragalus inflexus – bent milk-vetch, hairy milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; south-central Washington to Oregon, east to Idaho and Montana.
Habitat: Dry hillsides in sagebrush desert.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
Astragalus kentrophyta – spiny milk-vetch, thistle milk-vetch
Distribution: Known historically from Walla Walla County but considered extirpated; southern Alberta to east-central California, east to Rocky Mountains and northern Great Plains.
Habitat: Sandy deserts to alpine ridges.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
• var. douglasii – spiny millk-vetch, thistle milk-vetch
Astragalus laxmannii – Laxmann's milk-vetch, standing milk-vetch
Distribution: Occurring in north-central and eastern Washington; Yukon Territory to Washington, east to the Rocky Mountains and Minnesota.
Habitat: Prairies to rocky foothills in sagebrush desert and ponderosa pine forest.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• var. robustior – standing milk-vetch
Astragalus leibergii – Leiberg's milk-vetch
Distribution: Endemic to Douglas, Kittitas and Chelan counties of central Washington.
Habitat: Dry hillsides and plains, commonly in sagebrush scabland on basalt.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus lentiginosus – freckled milk-vetch, specklepod milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Montana and Texas.
Habitat: Open areas, desert flats to subalpine slopes.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
• var. lentiginosus – freckled milk-vetch, specklepod milk-vetch
Astragalus lyallii – Lyall's milk-vetch
Distribution: Endemic to Washington from Kittitas and Douglas counties south to Benton, east to Grant and Adams counties.
Habitat: Sagebrush and desert areas, especially on sand dunes.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus microcystis – lesser-bladder milk-vetch
Distribution: Occurring chiefly east of the Cascades crest in the northeastern counties of Washington, but also disjunct on the Olympic Peninsula; southern British Columbia to Washington, east to Montana and Wyoming.
Habitat: Prairies and foothills to ponderosa pine forests.
Origin: Native
Flowers: May-July
Growth Duration: Perennial
Astragalus misellus – pauper milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; Washington to Oregon.
Habitat: Dry, open areas in shrub-steppe.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
• var. pauper – pauper milk-vetch
Astragalus miser – weedy milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to central Washington, Rocky Mountains and northern Great Plains.
Habitat: Grasslands and foothills to montane forests, dry ridges and occasionally alpine meadows.
Origin: Native
Flowers: April-July
Growth Duration: Perennial
• var. miser – weedy milk-vetch
• var. serotinus – weedy milk-vetch
Astragalus pulsiferae – Ames's milk-vetch
Distribution: Known only from Mt. Adams and Klickitat County in Washington; Occurring in the northern Sierra Nevada of California and adjacent Nevada; not reported from Oregon.
Habitat: Sandy and gravelly flats in sagebrush and open pine forests on basalt.
Origin: Native
Flowers: June-July
Growth Duration: Perennial
• var. suksdorfii – Ames's milk-vetch
Astragalus purshii – Pursh's milk-vetch, woolly-pod milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Prairies and sagebrush deserts, foothills and lower mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
• var. glareosus – woolly-pod milk-vetch
• var. purshii – Pursh's milk-vetch, woolly-pod milk-vetch
Astragalus reventiformis – Yakima milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; Washington to Sherman County in Oregon.
Habitat: Shrub-steppe to low, dry, open ponderosa pine forests.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus reventus – Blue Mts. milk-vetch, longleaf milk-vetch
Distribution: Occurring east of the Cascades crest in the southeastern counties in Washington; Washington to northeastern Oregon.
Habitat: Pondersoa pine forest openings at low to moderate elevations.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus riparius – Piper's milk-vetch
Distribution: Occurring east of the Cascades crest in the southeastern counties in Washington; southeastern WA east to adjacent Idaho.
Habitat: Dry bluffs and canyon banks.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus robbinsii – Robbins's milk-vetch
Distribution: Occurring east of the Cascades crest in the northern counties in Washington; Alaska to Oregon,east to Alberta and south in the Rocky Mountains to Colorado, also in eastern North America.
Habitat: Stream banks and alpine slopes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• var. minor – Robbin's milk-vetch
Astragalus sclerocarpus – stalked-pod milk-vetch, The Dalles milk-vetch, woody-pod milk-vetch
Distribution: Occurring east of the Cascades crest chiefly in the Columbia River Basin and Columbia River Gorge in Washington; south-central British Columbia to north-central Oregon.
Habitat: Dunes and sandy barrens, low elevation
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus sheldonii – Sheldon's milk-vetch
Distribution: Occurring east of the Cascades crest in Asotin County in Washington; southeastern Washington to Oregon, east to Idaho.
Habitat: Shrub-steppe and ponderosa pine forest openings.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus sinuatus – Whited's milk-vetch
Distribution: Endemic to Chelan County in Washington.
Habitat: Among sagebrush on rocky hillsides.
Origin: Native
Flowers: May
Growth Duration: Perennial
Astragalus spaldingii – Spalding's milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; central Washington to northeast Oregon, east to western Idaho.
Habitat: Sagebrush and grasslands in the foothills and valleys.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus speirocarpus – curve-pod milk-vetch, medic milk-vetch, spiral-pod milk-vetch
Distribution: Endemic to Washington from Kittitas County south to Klickitat County, east to Grant County,
Habitat: Sagebrush desert.
Origin: Native
Flowers: April-May
Growth Duration: Perennial
Astragalus succumbens – crouching milk-vetch, sprawling milk-vetch
Distribution: Occurring east of the Cascades crest in Washington from Kittitas and Grant counties south; Washington to Umatilla and Gilliam Counties, Oregon.
Habitat: Sagebrush deserts, sandy barrens and lower foothills.
Origin: Native
Flowers: April-June
Growth Duration: Perennial
Astragalus tenellus – pulse milkvetch
Distribution: Disjunct in Douglas County in Washington; Yukon to southeastern Oregon and Nevada, east to Rocky Mountains.
Habitat: Prairies and foothills to lower mountains.
Origin: Native
Flowers: May
Growth Duration: Perennial
Astragalus tweedyi – Tweedy's milk-vetch
Distribution: Occurring east of the Cascades crest in Washington, from Yakima County south; central Washingtonto north-central Oregon near the Columbia River and lower Deschutes River.
Habitat: Sagebrush plains and foothills.
Origin: Native
Flowers: May-June
Growth Duration: Perennial
Astragalus whitneyi – balloon milk-vetch
Distribution: Occurring east of the Cascades crest in Washington; central Washington to California, east to Idaho and Nevada.
Habitat: High, open, rocky ridges and slopes, often in serpentine.
Origin: Native
Flowers: May-August
Growth Duration: Perennial
• var. sonneanus – balloon milk-vetch
Athyrium distentifolium – alpine lady-fern
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Alberta, Montana, Wyoming and Colorado; also in northeastern Canada and Greenland.
Habitat: Open, rocky slopes and along streams at mid- to high elevations in the mountains.
Origin: Native
Growth Duration: Perennial
• ssp. americanum – American alpine lady-fern
Athyrium filix-femina – lady-fern
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast; circumboreal.
Habitat: Moist woods, meadows, forest edge, and shaded riparian corridors from low to middle elevations.
Origin: Native
Spores: May-September
Growth Duration: Perennial
• ssp. cyclosorum – lady fern, northwestern lady fern
Athysanus pusillus – sandweed
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Montana.
Habitat: Dry, open, often grassy places.
Origin: Native
Flowers: March-June
Growth Duration: Annual
Atocion armeria – sweet William catchfly
Distribution: Occurring in scattered locations west of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Wastelots, roadsides, and other disturbed areas.
Origin: Introduced from Europe
Flowers: June-July
Growth Duration: Annual
Atriplex argentea – silver orache, silverscale orache
Distribution: Occurring east of the Cascades crest in Washington; central British Columbia to California, east to the Great Plains.
Habitat: Dry or alkaline soil.
Origin: Native
Flowers: July-September
Growth Duration: Annual, Perennial
• var. argentea – silver saltbush, silverscale
Atriplex canescens – fourwing saltbush, hoary saltbush, shadscale, wingscale
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to the Great Plains.
Habitat: Sand or gravel slopes and sagebrush flats, saline or not.
Origin: Native
Flowers: June-August
Growth Duration: Perennial
• var. canescens – hoary saltbush
Atriplex dioica – thickleaf orache, saline saltbush
Distribution: Occurring on both sides of the Cascades crest in Washington, but particularly common along the inner and outer marine coast; Yukon Territory to California, east to the Atlantic Coast.
Habitat: Salt marshes, sea beaches and headlands, also inland on disturbed or saline ground;
Origin: Native
Flowers: June-September
Growth Duration: Annual
Atriplex gardneri – Gardner's saltbush
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Sagebrush-steppe desert.
Origin: Native
Flowers: July-September
Growth Duration: Perennial
• var. falcata – moundscale, gardner's saltbush, sickle saltbush, saltsage
Atriplex gmelinii – Gmelin's orache, Gmelin's saltbush
Distribution: Occurring west of the Cascades crest along the coast in Washington; Alaska to California.
Habitat: On coastal beaches, strands, and rocky outcroppings near the high tide in saline soil.
Origin: Native
Flowers: June-September
Growth Duration: Annual
• var. gmelinii – Gmelin's orache, Gmelin's saltbush
Atriplex heterosperma – orache, Russian atriplex orache
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and Great Plains; also in eastern North America.
Habitat: Riparian zones and adjacent fields; tolerant of alkaline.
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Annual
Atriplex hortensis – garden orache, French spinach
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to the Great Plains and in scattered locations in eastern North America.
Habitat: Disturbed areas, often where seasonally moist.
Origin: Introduced from Asia
Flowers: July-August
Growth Duration: Annual
Atriplex littoralis – grassleaf orache, narrow-leaved orache
Distribution: Occurring west of the Cascades crest in Washington; also occurring in eastern North America.
Habitat: Coastal shoreline.
Origin: Introduced from Eurasia
Flowers: June-September
Growth Duration: Annual, Perennial
Atriplex longipes – long-stalked orache, Baltic saltbush
Distribution: Occurring west of the Cascades crest in northwestern Washington; southwestern British Columbia to northwestern Washington.
Habitat: Marine gravel, mudflats.
Origin: Introduced from Eurasia
Flowers: June-September
Growth Duration: Annual
Atriplex oblongifolia – oblongleaf orache
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to Washington, east to Alberta and Montana.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Europe
Flowers: June-September
Growth Duration: Annual
Atriplex patula – halberdleaf orache, spear orache
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic.
Habitat: Coastal and inland, saline or alkaline soil.
Origin: Introduced from Eurasia
Flowers: June-September
Growth Duration: Annual
Atriplex prostrata – fat hen, hastate orache, thin-leaf orache
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, in scattered location across Canada and the U.S. to the Atlantic Coast.
Habitat: Along the coast in saline soils, beaches, and strands; inland in alkaline soils.
Origin: Introduced from Eurasia
Flowers: June-September
Growth Duration: Annual
Atriplex rosea – red orache, tumbling orache
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and Great Plains; also in scattered locations in central and eastern U.S.
Habitat: Weedy species of irrigated land and roadsides.
Origin: Introduced from Eurasia
Flowers: July-September
Growth Duration: Annual
Atriplex truncata – wedge orache, wedgeleaf orache, wedgescale orache
Distribution: Occurring east of the Cascades crest in Washington; central British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Alkaline soil, flats and shores.
Origin: Native
Flowers: June-August
Growth Duration: Annual
Aubrieta deltoidea – rockcress
Habitat: Disturbed areas, where escaping from nearby cultivation.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial
Avena barbata – barbed oats
Distribution: Occurring chiefly west of the Cascades crest in Washington; Washington to California, east to Montana, Arizona, and New Mexico.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced Eurasian
Flowers: May-June
Growth Duration: Annual
Avena fatua – wild oats
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Eurasia
Flowers: May-September
Growth Duration: Annual
Avena sativa – cultivated oats
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from the Mediterranean region
Flowers: June-August
Growth Duration: Annual
Azolla filiculoides – duckweed fern, large mosquito fern
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Idaho and western Montana.
Habitat: Ponds, backwaters, slow-moving streams.
Origin: Native
Growth Duration: Annual
Azolla microphylla – Mexican 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
Growth Duration: Annual, Perennial
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