Western wahoo (Euonymus occidentalis)
Distribution: Occurring west of the Cascades crest in southwestern Washington; British Columbia to California.
Habitat: Moist woods at low to middle elevations.
Origin: Native
Flowers: May-June
Growth Duration: Perennial

Thick-leaved wake-robin (Trillium crassifolium)
Distribution: Occurring east of the Cascades crest in the Wenatchee Mountains and in the Blue Mountains; central Washington, and in Idaho eastern Oregon.
Habitat: Open woods vegetated rock outcrops.
Origin: Native
Flowers: March-June
Growth Duration: Perennial

Slimleaf wall rocket (Diplotaxis tenuifolia)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California, also in the southern and eastern U.S.
Habitat: Disturbed areas, roadsides.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Perennial

Pale wallflower (Erysimum occidentale)
Distribution: Occurring east of the Cascades crest in Washington; northern Washington to eastern Oregon.
Habitat: Sagebrush hills and valleys.
Origin: Native
Flowers: March-May
Growth Duration: Biennial, Perennial

Sand-dwelling wallflower (Erysimum arenicola)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon.
Habitat: Open ridges and rock crevices, middle elevations to the alpine.
Origin: Native
Flowers: June-September
Growth Duration: Perennial

Wallflower (Erysimum cheiri)
Distribution: Occurring west of the Cascades crest in Washington; Yukon Territory to California, and in scattered locations in eastern North America.
Habitat: Disturbed areas, often escaped from cultivation.
Origin: Introduced
Flowers: April-June
Growth Duration: Perennial

Wormseed wallflower (Erysimum cheiranthoides)
Distribution: Occurring chiefly east of the Cascades crest in Washington; widely distributed throughout much of North America.
Habitat: Disturbed areas including fields, roadsides and wastelots, often where moist.
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Annual

English walnut (Juglans regia)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon, east to Idaho; also in the northeastern U.S.
Habitat: Fields, roadsides, wastelots, and other disturbed areas, where escaping from cultivation
Origin: Introduced from Europe
Flowers: April-May
Growth Duration: Perennial

Northern California walnut (Juglans hindsii)
Distribution: Occurring east of the Cascades crest in Washington; south-central Washington to western Oregon; native to southwestern Oregon and California.
Habitat: Fields, roadsides, homesteads, and other disturbed, open areas.
Origin: Introduced from southwestern Oregon and California
Flowers: April-June
Growth Duration: Perennial

Wapato (Sagittaria latifolia)
Distribution: Occurring on both sides of the Cascades in Washington; Vancouver Island, British Columbia to central California; central North America to the Atlantic Coast.
Habitat: Ditches, ponds, lakes, swampy areas.
Origin: Native
Flowers: July-September
Growth Duration: Perennial

Lesser wartcress (Lepidium didymum)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California, Arizona, and Texas eastward and northward to the Atlantic Coast.
Habitat: Roadsides, gardens and wasteland.
Origin: Introduced from South America (or possibly Eurasia)
Flowers: May-July
Growth Duration: Annual, Biennial

Wartweed (Euphorbia helioscopia)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California, east to the northern Rocky Mountains and northern Great Plains, Texas, and eastern North America.
Habitat: Weed of cultivated areas and abondoned gardens.
Origin: Introduced from Eurasia
Flowers: April-July
Growth Duration: Annual

European water plantain (Alisma plantago-aquatica)
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

Northern water plantain (Alisma triviale)
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

Water purslane (Ludwigia palustris)
Distribution: Occurring west of the Cascades crest and along the Columbia River in Washington; southern British Columbia to California, east to Idaho, east across the southwestern U.S. and southern Great Plains to eastern North America; also occurring in New World Tropics and Eurasia.
Habitat: Lakes, marshes, peatlands, shores, and wet meadows.
Origin: Native
Flowers: July-September
Growth Duration: Perennial

Water-clover (Marsilea oligospora)
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Montana, Wyoming, and Utah.
Habitat: Ponds and marshes, in wet depressions in sagebrush and less commonly on river margins.
Origin: Native
Spores: June-October
Growth Duration: Perennial

Bulblet-bearing water-hemlock (Cicuta bulbifera)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to southern Oregon, east to Newfoundland and Virginia,
Habitat: Marshes, bogs, wet meadows and standing water, lowlands to mountain valleys.
Origin: Native
Flowers: July-September
Growth Duration: Perennial

Douglas' water-hemlock (Cicuta douglasii)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to Oregon, east to Alberta, Montana and Wyoming.
Habitat: Marshes, ditches, and wet low places, from low to middle elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Western water-hemlock (Cicuta douglasii)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to Oregon, east to Alberta, Montana and Wyoming.
Habitat: Marshes, ditches, and wet low places, from low to middle elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

European water-horehound (Lycopus europaeus)
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Oregon; also in eastern North America.
Habitat: Wetlands and shorelines.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial

Disk water-hyssop (Bacopa rotundifolia)
Distribution: Occurring chiefly east of the Cascades crest in south-central Washington; south-central Washington to California, east to the Rocky Mountains, native to central and eastern North America.
Habitat: Mudfalts, mud-bottomed pools, backchannels, and other slow-moving water of streams and rivers.
Origin: Introduced from central and eastern North America
Flowers: July-September
Growth Duration: Perennial

American water-lily (Nymphaea odorata)
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, east to central and eastern North America, where native.
Habitat: Lowland ponds and lakes.
Origin: Introduced from central and eastern North America
Flowers: June-October
Growth Duration: Perennial

Pygmy water-lily (Nymphaea tetragona)
Distribution: Known historically in Washington from west of the Cascades crest in Whatcom County; Alaska to British Columbia, east to Northwest Territories, Alberta, Montana, and Manitoba.
Habitat: Pond and lake margins, where emergent.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Various-leaved water-milfoil (Myriophyllum heterophyllum)
Distribution: Occurring west of the Cascades crest, where known only from the Puget Sound lowlands; British Columbia to Washington, native from Texas to central and eastern North America.
Habitat: Lakes and ponds.
Origin: Introduced from central and eastern North America
Flowers: May-October
Growth Duration: Perennial

Guadalupe water-nymph (Najas guadalupensis)
Distribution: Occurring west of the Cascades crest in Washington; Washington to Baja California, east to the Atlantic Coast.
Habitat: Fresh water habitats.
Origin: Native
Flowers: June-August
Growth Duration: Annual

Slender water-nymph (Najas flexilis)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Montana, Colorado, Utah, and Arizona, east across the northern Great Plains to the Great Lakes region and eastern North America.
Habitat: Fresh to slightly brackish water.
Origin: Native
Flowers: April-August
Growth Duration: Annual

American water-parsley (Oenanthe sarmentosa)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California.
Habitat: Low elevation wet areas, often in standing water.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Hemlock water-parsnip (Sium suave)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Swampy places and shallow water of lakes, ponds, and backwater channels, from low to middle elevations.
Origin: Native
Flowers: July-August
Growth Duration: Perennial

Grass-leaved water-plantain (Alisma gramineum)
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

Autumn water-starwort (Callitriche hermaphroditica)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon, east across North America in scattered locations to the Atlantic Coast.
Habitat: Sloughs and streams.
Origin: Native
Flowers: July-September
Growth Duration: Perennial

Narrow-leaf water-starwort (Callitriche brutia)
Distribution: Reported for Washington, but no specimens seen; British Columbia to Oregon.
Habitat: Flowing streams or quiet waters.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial

Pond water-starwort (Callitriche stagnalis)
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, east to Montana; also in eastern North America.
Habitat: In streams, ponds, and ditches.
Origin: Introduced from Europe
Flowers: May-August
Growth Duration: Perennial

Vernal water-starwort (Callitriche palustris)
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: Sloughs and slow-moving fresh water.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Water-thyme (Hydrilla verticillata)
Distribution: Occurring west of the Cascades crest in Washington, where known only from King County; Washington, California, and in the southern and eastern U.S.
Habitat: Ponds, lakes, and slow-moving streams at low elevation.
Origin: Introduced from Eurasia
Growth Duration: Perennial

Australian waterclover (Marsilea mutica)
Distribution: Occurring in scattered counties west of the Cascades crest in Washington; also known from California and the southeastern U.S.
Habitat: Lowland ponds in water to 1 meter deep.
Origin: Introduced from Australia
Spores: June-October
Growth Duration: Perennial

Watercress (Nasturtium officinale)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Riparian zones and other wet areas.
Origin: Introduced from Europe
Flowers: May-September
Growth Duration: Perennial

Fendler's waterleaf (Hydrophyllum fendleri)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Utah.
Habitat: Thickets and moist open places, from lowlands to mid elevations in mountains.
Origin: Native
Flowers: May-August
Growth Duration: Perennial

Brazilian watermeal (Wolffia brasiliensis)
Distribution: Occurring chiefly west of the Cascades crest in Washington; southwestern British Columbia to California, also from the southern Great Plains east to the Atlantic Coast in the U.S.
Habitat: Ponds and standing water at low elevations.
Origin: Native
Growth Duration: Perennial

Northern watermeal (Wolffia borealis)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, and Utah, also from the central U.S. east to the Atlantic Coast.
Habitat: Ponds and standing water at low elevations
Origin: Native
Growth Duration: Perennial

Brazilian waterweed (Egeria densa)
Distribution: Occurring chiefly west of the Cascades crest in Washington; southwestern British Columbia to California, east across the southern half of the United States to the Atlantic.
Habitat: Ponds, lakes, and slow-moving water at low elevation.
Origin: Introduced from South America
Flowers: July-September
Growth Duration: Perennial

Common waterweed (Elodea canadensis)
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: Common in ponds, lakes, streams, rivers, and slow-moving waters.
Origin: Native
Flowers: July-September
Growth Duration: Perennial

Rocky Mountain waterweed (Elodea canadensis)
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: Common in ponds, lakes, streams, rivers, and slow-moving waters.
Origin: Native
Flowers: July-September
Growth Duration: Perennial

Waterweed (Egeria densa)
Distribution: Occurring chiefly west of the Cascades crest in Washington; southwestern British Columbia to California, east across the southern half of the United States to the Atlantic.
Habitat: Ponds, lakes, and slow-moving water at low elevation.
Origin: Introduced from South America
Flowers: July-September
Growth Duration: Perennial

California waterwort (Elatine californica)
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Montana, Utah, and New Mexico.
Habitat: Pools, pond shores, and stream banks.
Origin: Native
Flowers: June-August
Growth Duration: Annual

Pacific wax-myrtle (Morella californica)
Distribution: Occurring west of the Cascades crest along the outer coast in Washington; coastal Vancouver Island, British Columbia to California.
Habitat: Hillsides and sandy areas near the coast.
Origin: Native
Flowers: April-May
Growth Duration: Perennial

Prairie wedgescale (Sphenopholis obtusata)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Moist soil to standing water, stream and lake margins to grasslands.
Origin: Native
Flowers: June--July
Growth Duration: Annual, Perennial

Klamath weed (Hypericum perforatum)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Noxious weed of fields, meadows, roadsides, forest edge, wastelots, and other disturbed areas from the lowlands to near subalpine.
Origin: Introduced from Europe
Flowers: June-July
Growth Duration: Perennial

Pineapple weed (Matricaria discoidea)
Distribution: Widely distributed on both sides of the Cascades crest Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Fields, roadsiides, wastelots, and other disturbed, open areas.
Origin: Native
Flowers: May-September
Growth Duration: Annual

Pygmy weed (Crassula connata)
Distribution: Occurring west of the Cascades crest in Washington in San Juan County; British Columbia to California, east to Arizona and Texas.
Habitat: Sandy areas, paths and roadsides.
Origin: Native
Flowers: May-June
Growth Duration: Annual

Water pygmy weed (Crassula aquatica)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, and in the southeastern and northeastern regions of North America.
Habitat: Mud flats and vernal pools.
Origin: Native
Flowers: April-August
Growth Duration: Annual

Bread wheat (Triticum aestivum)
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: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Eurasia
Flowers: April-June
Growth Duration: Annual

Arctic wheatgrass (Elymus violaceus)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon, east to the Rocky Mountains, east across Canada to the Atlantic Coast.
Habitat: High montane to alpine rocks and grassland.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Bluebunch wheatgrass (Pseudoroegneria spicata)
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Sagebrush desert and ponderosa pine forest openings, occasionally to the subalpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Eurasian wheatgrass (Thinopyrum ponticum)
Distribution: Occurring chiefly east of the Cascades crest in Washington; Yukon Territory to California, east to the Great Plains.
Habitat: Disturbed areas including roadsides, wastelots, and agricultural fields.
Origin: Introduced from Eurasia
Flowers: May-June
Growth Duration: Perennial

Siberian wheatgrass (Agropyron fragile)
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

Thick-spiked wheatgrass (Elymus lanceolatus)
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, Great Plains, and Great Lakes region.
Habitat: Sand and clay soils, dry to mesic grasslands, and sagebrush.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Common whipplea (Whipplea modesta)
Distribution: Occurring on the Olympic Peninsula in Washington; Washington to California.
Habitat: Dry, rocky, open to lightly forested areas.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Asian white-top (Lepidium chalepense)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Great Lakes region.
Habitat: Disturbed areas, especially where dry, often associated with agriculture.
Origin: Introduced from Asia
Flowers: May-June
Growth Duration: Perennial

Alaska whitlow-grass (Draba stenoloba)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon, east to Alberta.
Habitat: Sublapine meadows to alpine slopes.
Origin: Native
Flowers: May-August
Growth Duration: Annual, Biennial, Perennial

Alpine whitlow-grass (Draba aureola)
Distribution: Occurring west of the Cascades crest in Washington in the Mount Rainier area; Washington to northern California
Habitat: Alpine areas, including scree and moraine areas.
Origin: Native
Flowers: June-August
Growth Duration: Biennial, Perennial

Carolina whitlow-grass (Draba reptans)
Distribution: Occurring east of the Cascades crest in Washington; central British Columbia to California, east to the Atlantic Coast.
Habitat: Desert plains and foothills.
Origin: Native
Flowers: March-May
Growth Duration: Annual

Dense-leaf whitlow-grass (Draba densifolia)
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to Alberta, Idaho, Wyoming, Nevada and Utah.
Habitat: Open, rocky places from mid- to high elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Few-seeded whitlow-grass (Draba oligosperma)
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska to California, east to Colorado.
Habitat: From sagebrush plains to alpine slopes.
Origin: Native
Flowers: May-August
Growth Duration: Perennial

Great alpine whitlow-grass (Draba aureola)
Distribution: Occurring west of the Cascades crest in Washington in the Mount Rainier area; Washington to northern California
Habitat: Alpine areas, including scree and moraine areas.
Origin: Native
Flowers: June-August
Growth Duration: Biennial, Perennial

Payson's whitlow-grass (Draba novolympica)
Distribution: Occurring in the Olympics and Cascades mountains of Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Open slopes, talus ridges, and other exposed areas in the alpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Snowbed whitlow-grass (Draba crassifolia)
Distribution: Occurring in the Olympic Mountains and North Cascades in Washington; Alaska to Washington, Nevada, east to the Rocky Mountains; east across northern Canada to Greenland; northern Europe.
Habitat: Subalpine and alpine meadows, often in rock crevices and outcroppings.
Origin: Native
Flowers: June-August
Growth Duration: Annual, Perennial

Tall whitlow-grass (Draba praealta)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, e to Northwest Territories, Alberta Montana, Idaho, Wyoming, and central Nevada.
Habitat: Montane woodland to subalpine ridges.
Origin: Native
Flowers: June-August
Growth Duration: Biennial, Perennial

Woodland whitlow-grass (Draba nemorosa)
Distribution: In scattered locations on both sides of the Cascades crest in Washington; Alaska to California, east across the northern half of the U.S. and Canada to the Atlantic Coast.
Habitat: Disturbed open areas and forest edges at low to middle elevations.
Origin: Introduced from Eurasia
Flowers: March-June
Growth Duration: Annual

Whitlow-wort (Draba lonchocarpa)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Northwest Territories, south in Rocky mountains to Colorado.
Habitat: Alpine slopes, talus, and rocky outcroppings.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Northern wild rice (Zizania palustris)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to Oregon and Arizona, east to Idaho and Montana; also in central and eastern North America, where native.
Habitat: Emergent in marshes, lakes, slow channels
Origin: Introduced from eastern and cerntal North America
Flowers: July-September
Growth Duration: Annual

Russian wild-rye (Psathyrostachys juncea)
Distribution: Occurring east of the Cascades crest in Washington, where likely more common than specimens or photo evidence suggests; Alaska to Washington, also in the Rocky Mountains and Great Plains.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Perennial

Beardless wildrye (Leymus triticoides)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and Texas.
Habitat: Dry to moist, often alkaline meadows.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Creeping wildrye (Elymus repens)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast; circumboreal.
Habitat: Fields, roadsides, meadows, pastures, wastelots, and other disturbed open areas.
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Perennial

Great Basin wildrye (Leymus cinereus)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the northern Great Plains.
Habitat: Sagebrush-steppe, arid grasslands, forest edges, and other dry, open areas in the intermountain west.
Origin: Native
Flowers: June-July
Growth Duration: Perennial

Northwest wildrye (Elymus hirsutus)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to Oregon, east to Alberta and Idaho.
Habitat: Forests, thickets, and grasslands.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Scribner's wildrye (Elymus scribneri)
Distribution: Occurring in the Cascades Range in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Open, rocky, often windswept subalpine and alpine regions.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Wawawai wildrye (Elymus wawawaiensis)
Distribution: Occurring east of the Cascades crest in Washington; southeastern Washington to eastern Oregon and western Idaho.
Habitat: Shallow, rocky soils.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Alpine willow (Salix petrophila)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Alpine areas, often near melting snowbanks.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Arroyo willow (Salix lasiolepis)
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Idaho, Utah, New Mexico, and Texas.
Habitat: Riparian corridors from low to middle elevations.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Basket willow (Salix purpurea)
Distribution: Occurring in scattered lowland locations west of the Cascades crest in Washington; British Columbia to California, also in Utah, and from the central U.S. and Canada to the Atlantic Coast.
Habitat: Ditches, floodplains, and shores.
Origin: Introduced from Europe
Flowers: April-May
Growth Duration: Perennial

Bog willow (Salix pedicellaris)
Distribution: Occurring on both sides of the Cascades crest in Washington; Territory to Oregon, east across Canada and northern U.S. to the Atlantic Coast.
Habitat: Bogs, fens, and similar wet meadows.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Cascade willow (Salix cascadensis)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Mt. Rainier, also in western Montana, Wyoming, Utah, and Colorado.
Habitat: High elevations in the mountains in subalpine and alpine habitats
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Corkscrew willow (Salix matsudana)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; occurring in scattered locations across North America.
Habitat: Disturbed shorelines, where escaping from cultivation.
Origin: Introduced from Asia
Flowers: April-May
Growth Duration: Perennial

Crack willow (Salix fragilis)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon, east to Idaho and Montana.
Habitat: Sagebrush desert, including sand dunes, often where disturbed.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial

Dusky willow (Salix melanopsis)
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the northern and central Rocky Mountains.
Habitat: Riparian zones including streambanks, pond and lake margins, and subalpine meadows.
Origin: Native
Flowers: June-July
Growth Duration: Perennial

False mountain willow (Salix pseudomonticola)
Distribution: Occurring on both sides of the Cascades crest in the North Cascades in Washington; Alaska to Washington, east across the northern U.S. and Canada to Quebec.
Habitat: Wet meadows, forested wetlands, and other riparian areas in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Geyer's willow (Salix geyeriana)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Lowland riparian areas including streambanks and pond and lake margins.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Gray willow (Salix glauca)
Distribution: Occurring in the Cascades and Olympic Mountains in Washington; Alaska to northwestern Washington, east to western Montana.
Habitat: Middle elevations to above timberline in moist places to open slopes.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Maccalla's willow (Salix maccalliana)
Distribution: Occurring east of the Cascades crest in Washington; Yukon Territory to Washington, east across northern North America to Quebec.
Habitat: Wet meadows, bogs, fens, streambanks and lakeshores from low to moderate elevations in the mountains.
Origin: Native
Flowers: May-June
Growth Duration: Perennial

Narrow-leaf willow (Salix exigua)
Distribution: Occurring chiefly east of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to California, east to the Rocky Mountains, and southern Great Plains.
Habitat: Riparian areas, gravel bars, lake and pond shore margins
Origin: Native
Flowers: April-May
Growth Duration: Perennial

Pacific willow (Salix lasiandra)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Riparian areas from the coast to the mountains.
Origin: Native
Flowers: March-June
Growth Duration: Perennial

Plane-leaf willow (Salix planifolia)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Wet meadows, lake margins, streambanks and other riparian areas in the alpine and subalpine.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Rock willow (Salix vestita)
Distribution: Occurring in the North Cascades in Washington; British Columbia to Oregon, east to Alberta and in Montana; also in cetnral and eastern Canada.
Habitat: Moist forest opening, streambanks, and other riparian areas in montane and subalpine habitats.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Sage-leaf willow (Salix candida)
Distribution: Occurring east of the Cascades crest in northeastern Washington; Alaska to northeastern Washington, east across the northern U.S. and Canada to the Atlantic Coast.
Habitat: Lakeshores, pond margins, streambanks, and other riparian areas.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Sessile-leaf willow (Salix sessilifolia)
Distribution: Occurring chiefly west of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to Oregon.
Habitat: Riparian corridors at low to middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Sierran willow (Salix eastwoodiae)
Distribution: In the mountains of Washington; Washington south to California, east to Montana, Wyoming, and Nevada.
Habitat: Alpine and subalpine meadows.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Tea-leaved willow (Salix planifolia)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Wet meadows, lake margins, streambanks and other riparian areas in the alpine and subalpine.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Variable willow (Salix commutata)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon, east to Northwest Territory, Sasketchawan, and Montana.
Habitat: Moist areas, mid- to high elevations in the mountains.
Origin: Native
Flowers: June-September
Growth Duration: Perennial

Willow weed (Persicaria lapathifolia)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Streambanks, pond and lakeshores and other wet places.
Origin: Native
Flowers: May-September
Growth Duration: Perennial

Autumn willow-herb (Epilobium brachycarpum)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains, northern Great Plains, and Great Lakes region.
Habitat: Common in dry, open meadows and grasslands to lightly wooded areas.
Origin: Native
Flowers: July-August
Growth Duration: Annual

Broad-leaved willow-herb (Epilobium montanum)
Origin: Introduced

California willow-herb (Epilobium minutum)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, Utah, and Arizona.
Habitat: Dry or gravelly soil, sea level to mid-elevations in the mountains.
Origin: Native
Flowers: April-August
Growth Duration: Annual

Ciliate willow-herb (Epilobium ciliatum)
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.
Habitat: Moist soil from lowlands to middle elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Dense-flower willow-herb (Epilobium densiflorum)
Distribution: Occurring on both sides of the Cascades in Washington; Vancouver Island, British Columbia to Baja California, east to Montana, Utah, and Arizona.
Habitat: Moist to seasonally moist meadows, springs, shores, riparian zones, slopes, roadsides, and ditches.
Origin: Native
Flowers: July-September
Growth Duration: Annual

Great willow-herb (Epilobium hirsutum)
Distribution: Occurring on both sides of the Cascades crest in Washington; southern British Columbia to Oregon; also in upper central and northeastern North America.
Habitat: Garden escape in wet areas at low elevations.
Origin: Introduced from Eurasia
Flowers: June-August
Growth Duration: Perennial

Hall's willow-herb (Epilobium hallianum)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Moist to wet areas from montane to alpine habitats.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Marsh willow-herb (Epilobium palustre)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska east to California, east to the Rocky Mountains, Great Lakes region, and the Atlantic coast;.
Habitat: Wet soil, often in bogs.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Oregon willow-herb (Epilobium oregonense)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Montana, Wyoming, and Arizona.
Habitat: Streambanks, bogs, and wet meadows from moderate elevations in mountains to alpine.
Origin: Native
Flowers: June-September
Growth Duration: Perennial

Slender-fruit willow-herb (Epilobium leptocarpum)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; Alaska to Oregon, east to Alberta and Idaho.
Habitat: Damp rocky slopes and ledges, shores, and wet meadow margins.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Smooth willow-herb (Epilobium campestre)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Mud flats, vernal pools.
Origin: Native
Flowers: June-July
Growth Duration: Annual

Tall annual willow-herb (Epilobium brachycarpum)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains, northern Great Plains, and Great Lakes region.
Habitat: Common in dry, open meadows and grasslands to lightly wooded areas.
Origin: Native
Flowers: July-August
Growth Duration: Annual

Watson's willow-herb (Epilobium ciliatum)
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.
Habitat: Moist soil from lowlands to middle elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Yellow willow-herb (Epilobium luteum)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Alberta.
Habitat: Stream banks and wet areas at mid- to high elevations in the mountains.
Origin: Native
Flowers: July-September
Growth Duration: Perennial

Drummond's windflower (Anemone drummondii)
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

Northern windflower (Anemone parviflora)
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

Piper's windflower (Anemone piperi)
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

Bitter wintercress (Barbarea vulgaris)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Garden escape, found chiefly in wet places.
Origin: Introduced from Eurasia
Flowers: April-July
Growth Duration: Biennial

Winterfat (Krascheninnikovia lanata)
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to the Great Plains.
Habitat: Sagebrush plains and foothills, often in saline or alkaline soil.
Origin: Native
Flowers: April-July
Growth Duration: Perennial

Common pink wintergreen (Pyrola asarifolia)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Moist ground in woodlands and forests, from low to middle elevations.
Origin: Native
Flowers: June-September
Growth Duration: Perennial

Leafless wintergreen (Pyrola aphylla)
Distribution: Occurring on both sides of the Cascades crest in Washington; southwestern British Columbia to Baja California, east to Idaho.
Habitat: Dry coniferous forests at low to moderate elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Liver-leaf wintergreen (Pyrola asarifolia)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Moist ground in woodlands and forests, from low to middle elevations.
Origin: Native
Flowers: June-September
Growth Duration: Perennial

Snowline wintergreen (Pyrola minor)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains; east across Canada and northern U.S. to the Atlantic Coast.
Habitat: Uncommon, mostly in moist areas in coniferous woods, moderate to high elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

White-vein wintergreen (Pyrola picta)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Coniferous woods, especially ponderosa pine, moderate to mid-elevations in the mountains
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Stiff-branched wirelettuce (Stephanomeria paniculata)
Distribution: Occurring east of the Cascades in Washington; Washington to California, east to Idaho.
Habitat: Dry, open places in the plains and foothills.
Origin: Native
Flowers: July-September
Growth Duration: Annual

Witchgrass (Panicum capillare)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Moist and irrigated areas, along streams and around ponds.
Origin: Native
Flowers: June-September
Growth Duration: Annual

Wolfberry (Elaeagnus commutata)
Distribution: Occurring east of the Cascades crest in Washington; Alaska to Washington and California (but not Oregon), east to the Rocky Mountains, Great Plains, and eastern Canada.
Habitat: Gravel benches and scabland, commonly along watercourses.
Origin: Native
Flowers: June-July
Growth Duration: Perennial

John Day wood beauty (Drymocallis campanulata)
Distribution: south-central Washington to north-central and east-central Oregon.
Habitat: Basalt cliffs, talus, canyons, and washes.
Origin: Native
Flowers: April-May
Growth Duration: Perennial

Crested wood-fern (Dryopteris cristata)
Distribution: Occurring east of the Cascades crest in northeastern Washington; Alaska to Idaho, east across northern U.S. and Canada to eastern North America; also in Europe.
Habitat: Moist woods and thickets at middle elevations in the mountains.
Origin: Native
Growth Duration: Perennial

Spreading wood-fern (Dryopteris expansa)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Alberta, Idaho, and Montana.
Habitat: Moist to wet woods and streambanks.
Origin: Native
Growth Duration: Perennial

Slender wood-reed (Cinna latifolia)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, and eastern North America.
Habitat: Moist woods and meadows, sea level to subalpine.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Creeping yellow wood-sorrel (Oxalis corniculata)
Distribution: Occurring chiefly west of the Cascades crest and along the Columbia River in Washington; British Columbia to California, east across most of North America to the Atlantic Coast;
Habitat: A weed of gardens, disturbed areas, and waste places.
Origin: Introduced from Europe
Flowers: May-October
Growth Duration: Perennial

Oregon wood-sorrel (Oxalis oregana)
Distribution: Occurring west of the Casades crest in Washington; Olympic Mountains and west slope of the Cascades in Washington; British Columbia south to California.
Habitat: Moist woods, low to moderate elevations.
Origin: Native
Flowers: April-September
Growth Duration: Perennial

Trillium-leaf wood-sorrel (Oxalis trilliifolia)
Distribution: Occurring west of the Cascades crest in Washington; Washington to northwest California, disjunct in northern Idaho.
Habitat: Meadows and moist woods in the coastal mountains and up to 6000 feet in the Cascades.
Origin: Native
Flowers: May-August
Growth Duration: Perennial

Western yellow wood-sorrel (Oxalis suksdorfii)
Distribution: Occurring west of the Cascades crest in Washington; southern Washington to northwest California.
Habitat: Low elevations, usually in moist, coastal woods but sometimes on rather dry, open slopes.
Origin: Native
Flowers: April-August
Growth Duration: Perennial

Bulbous woodland star (Lithophragma glabrum)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Grasslands and sagebrush desert to ponderosa pine and Douglas-fir forest openings.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Small-flower woodland star (Lithophragma parviflorum)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and Great Plains.
Habitat: Prairies, balds, sagebrush desert, and forest openings, sea level to mid-elevations in the mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Common woodrush (Luzula multiflora)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon, east to Alberta and western Montana; also in northeastern United States.
Habitat: Fields, meadows, open woods and clearings, at low to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Field woodrush (Luzula campestris)
Distribution: Occurring west of the Cascades crest in Washington; southwestern British Columbia to western Washington; also in New England.
Habitat: Lowland lawns or dry, disturbed ground.
Origin: Introduced
Flowers: April-May
Growth Duration: Perennial

Large-anthered woodrush (Luzula macrantha)
Distribution: Occurring chiefly west of the Cascades crest and in the Columbia River Gorge in Washington; southwestern British Columbia to California.
Habitat: Balds, prairies, grasslands, and forest openings at low to moderate elevations.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Pacific woodrush (Luzula comosa)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Coastal to montane openings, rocky slopes, forests and shores.
Origin: Native
Flowers: April-July
Growth Duration: Perennial

Prairie woodrush (Luzula macrantha)
Distribution: Occurring chiefly west of the Cascades crest and in the Columbia River Gorge in Washington; southwestern British Columbia to California.
Habitat: Balds, prairies, grasslands, and forest openings at low to moderate elevations.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Smooth woodrush (Luzula hitchcockii)
Distribution: Occurring on both sides of the Cascades crest in Washington; southern British Columbia to Crater Lake and the Wallowa Mountains of Oregon, east to Alberta, Montana, and northwestern Wyoming.
Habitat: Montane forests to alpine slopes, ridges and meadows.
Origin: Native
Flowers: July-September
Growth Duration: Perennial

Spiked woodrush (Luzula spicata)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, east across northern Canada to northeastern North America; also in Eurasia.
Habitat: Subalpine to alpine slopes, moraines, and stream banks.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Woodsia (Woodsia scopulina)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, Great Plains, and scattered areas in eastern North America.
Habitat: Rock crevices, ledges and talus slopes in the mountains, and in less arid parts of the lowlands.
Origin: Native
Growth Duration: Perennial

Dwarf woolly-marbles (Psilocarphus brevissimus)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the northern Great Plains and Rocky Mountains.
Habitat: Dried beds of vernal pools.
Origin: Native
Flowers: May-July
Growth Duration: Annual

Slender woollyheads (Psilocarphus tenellus)
Distribution: Occurring on both sides of the Cascades crest in Washington; southwestern British Columbia to California, east to Idaho.
Habitat: Dry or seasonally moist barren or wooded slopes or flats, often on disturbed sites.
Origin: Native
Flowers: March-August
Growth Duration: Annual

Wilcox's woolstar (Eriastrum wilcoxii)
Distribution: Occurring east of the Cascades crest in central Washington; central Washington to southern California, east to southern Idaho and western Utah.
Habitat: Sagebrush desert in sandy or stony soil.
Origin: Native
Flowers: May-August
Growth Duration: Annual

Annual wormwood (Artemisia annua)
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

Biennial wormwood (Artemisia biennis)
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

Cascade wormwood (Artemisia tilesii)
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

Douglas's wormwood (Artemisia douglasiana)
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

Forked wormwood (Artemisia furcata)
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

Michaux's wormwood (Artemisia michauxiana)
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

Steller's wormwood (Artemisia stelleriana)
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

Swallow wort (Chelidonium majus)
Distribution: Occurring chiefly west of the Cascades crest in Washington; southern British Columbia to Oregon, east to Montana; also in eastern North America.
Habitat: Moist to dry woods, roadsides, fields, waste areas.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Biennial