Vascular Plants

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


Browse by scientific name:

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Scientific names beginning with S:
Sabulina basalticabasalt sandwort, Olympic sandwort
Distribution: Known only from the northeastern Olympic Mountains in Washington.
Habitat: Rocky outcroppings and exposed areas in the subalpine and alpine.
Origin: Native
Flowers: June-August
Sabulina macraslender sandwort, slender stitchwort
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to Oregon.
Habitat: Lowlands, prairies and coastal bluffs.
Origin: Native
Flowers: April-July
Sabulina nuttalliiNuttall's sandwort
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains.
Habitat: Sagebrush hills to alpine slopes, especially on gravelly benches or talus.
Origin: Native
Flowers: May-August
var. fragilis – brittle sandwort, brittle stichwort
var. nuttallii – Nuttall's sandwort
Sabulina pusillaannual sandwort, dwarf sandwort, dwarf stitchwort
Distribution: Occurring east of the Cascades crest from Klickitat County to the southeastern counties in Washington; southern Washington to California, east to northeastern Oregon and adjacent Idaho.
Habitat: Dry, rocky cliffs and outcroppings in sagebrush desert to ponderosa pine forest openings.
Origin: Native
Flowers: May-July
Sabulina rubellaboreal stitchwort
Distribution: Alaska to Greenland, south in the mountains to Oregon and New Mexico
Habitat: Subalpine to alpine meadows, ridges and talus slopes
Origin: Native
Flowers: June - August
Sabulina sororiaTwin Sisters sandwort
Distribution: Endemic to the Twin Sisters Range in Whatcom County.
Habitat: Rocky outcroppings and exposed areas.
Origin: Native
Flowers: June-August
Sagina apetalaannual pearlwort
Distribution: Occurring in the lowlands west of the Cascades crest in Washington; British Columbia south to California; Kansas.
Habitat: Waste ground.
Origin: Introduced from Europe
Flowers: May-June
Sagina decumbenswestern pearlwort
Distribution: Chiefly west of the Cascades in Washington; British Columbia south to southern California.
Habitat: Moist soil at low elevations, but not typically coastal.
Origin: Native
Flowers: May-August
ssp. occidentalis – western pearlwort
Sagina maximastick-stemmed pearlwort
Distribution: Occurring in counties along the coast in Washington; distinctly coastal, Alaska south to Monterey County, California.
Habitat: Moist sand or rocks.
Origin: Native
Flowers: June-September
ssp. crassicaulis – stick-stemmed pearlwort
Sagina procumbensbird-eye pearlwort
Distribution: Occurring on both sides of the Cascades crest in Washington, though more common west of the crest; Alaska to California, east to the Rocky Mountains, Great Lakes region, and northeastern North America.
Habitat: Moist areas, often where disturbed, at low elevations; common garden weed.
Origin: Introduced from Europe
Flowers: May-October
Sagina saginoidesalpine pearlwort, arctic pearlwort
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains in the U.S. and Alberta; east across northern Canada to Greenland.
Habitat: Open areas, typically where at least seasonally moist, from middle elevations to the alpine.
Origin: Native
Flowers: May-September.
Sagittaria cuneataarumleaf arrowhead, northern arrowhead, Sagittaria cuneaire, wapato
Distribution: East of the Cascades in Washington; British Columbia south to California, east to New York.
Habitat: Ponds, lake shores and ditches.
Origin: Native
Flowers: June-August
Sagittaria gramineagrassy arrowhead
Distribution: Occurring west of the Cascades in Washington; primary distribution is east of the Mississippi River.
Habitat: Wetlands, ponds, and lakes
Origin: Introduced
Flowers: June-August
Sagittaria latifoliacommon arrowhead, duck potato, wapato
Distribution: Occurring on both sides of the Cascades in Washington; Vancouver Island, British Columbia south to central California; primary distribution in central and eastern North America.
Habitat: Ditches, ponds, lakes, swampy areas.
Origin: Native
Flowers: July-September
Sagittaria platyphylladelta arrowhead
Distribution: Known from the Puget Sound lowlands in Washington; south-central U.S., and in scattered locations in central and northeastern U.S.
Habitat: Pond and lake margins.
Origin: Introduced
Flowers: June-August
Sagittaria rigidasessile-fruited arrowhead
Distribution: Occurring in lowland areas west of the Cascades crest in Washington; California; central U.S. and southern Canada east to northeastern U.S. and Canada; scattered locations elsewhere in U.S. and Canada.
Habitat: Pond and lake margins.
Origin: Introduced from eastern North America
Flowers: June-August
Sagittaria subulataawl-leaf arrowhead
Origin: Introduced from tidewaters in eastern North America
Salicornia depressalow saltwort
Distribution: Strictly coastal in Washington;
Habitat: Salt marshes.
Origin: Native
Flowers: July-September
Salicornia pacifica
Distribution: Along the coast in Washington; Alaska to Baja California.
Habitat: Salt marshes and beaches along coast.
Origin: Native
Flowers: June-October
Salicornia rubrared glasswort saltwort
Origin: Native
Flowers: July - September
Salix amygdaloidespeach-leaf willow
Distribution: East side of the Cascades in Washington; widely distributed throughout North America except in extreme northwestern and southeastern regions.
Habitat: Wetlands, streambanks, and other riparian areas.
Origin: Native
Flowers: March-May
Salix arcticaarctic willow
Distribution: Alaska, British Columbia to Labrador; northern Cascades in Washington, Wallowa Mountains in Oregon, and the Rockies in Idaho and Montana
Habitat: In wet to dry areas in the alpine.
Origin: Native
Flowers: June-August
Salix barclayibarclay's willow
Distribution: Chiefly in the Olympic and Cascade mountains of Washington; Alaska east to Northwest Territories, south to Oregon and Wyoming.
Habitat: Lakes, streams, and other riparian areas in subalpine and alpine zone.
Origin: Native
Flowers: June-August
Salix bebbianaBebb's willow, gray willow, long-beak willow
Distribution: Chiefly east of the Cascades in Washington; widely distributed throughout North America except for southcentral and southeastern U.S.
Habitat: Lakes, streams, and other riparian areas from low to moderate elevations in the mountains.
Origin: Native
Flowers: April-June
Salix boothiiBooth's willow
Distribution: In the Cascades of Washington; distributed in western North America from British Columbia east to Saskatchewan, south to California, east to Arizona.
Habitat: Wet subalpine meadows, streambanks, lakeshores, and other riparian areas.
Origin: Native
Flowers: May-July
Salix brachycarpashort-fruited willow
Distribution: Occurring east of the Cascades crest in Washington; Yukon Territory to California, east to the Rocky Mountains, and east across Canada to Quebec.
Habitat: Riparian areas, wetlands, and meadows from middle elevations to the subalpine.
Origin: Native
Flowers: April-June
var. brachycarpa – short-fruited willow
Salix candidasage willow, sage-leaf willow
Distribution: In the mountains of northeastern and southeastern Washington; widespread across North America from Alaska south to Washington, east through central U.S. to Canadian Maritimes.
Habitat: Lakeshores, pond margins, streambanks, and other riparian areas.
Origin: Native
Flowers: April-June
Salix cascadensisCascade willow
Distribution: In the Cascade Mountains of Washington; British Columbia south in the Cascades to Mt. Rainier, occasionally east to northeast Oregon, Idaho and Montana, south to Utah and Colorado.
Habitat: High elevations in the mountains in subalpine and alpine habitats
Origin: Native
Flowers: June-August
Salix commutataunder-green willow, variable willow
Distribution: Chiefly in the Olympic and Cascade mountains of Washington; Alaska and Yukon south to Oregon, occasionally east to idaho and Montana.
Habitat: Moist areas, mid- to high elevations in the mountains.
Origin: Native
Flowers: June-September
Salix drummondianaDrummond's willow
Distribution: In the East Cascades and mountains of eastern Washington; Yukon Territory east to Northwest Territories, south to California, east through the Rocky Mountains.
Habitat: Streambanks, lakeshores, floodplains, and other riparian areas in montane and subalpine habitats.
Origin: Native
Flowers: April-June
Salix eastwoodiaeSierran willow
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
Salix exiguacoyote willow, narrow-leaf willow
Distribution: Chiefly east of the Cascades in Washington; British Columbia and Alberta south to California, east through the Rocky Mountains to Nebraska and Texas.
Habitat: Riparian areas, gravel bars, lake and pond shore margins
Origin: Native
Flowers: April-May
var. columbiana – Columbia River willow
var. exigua – coyote willow, narrow-leaf willow
Salix farriaeFarr's willow
Distribution: Known only from Okanogan County in Washington; Yukon south to Oregon, east to Montana, Idaho and Wyoming.
Habitat: Wet meadows and riparian zones from montane to subalpine.
Origin: Native
Flowers: June-July
Salix fragiliscrack willow
Origin: Introduced
Salix geyerianaGeyer's willow
Distribution: Both sides of the Cascades in Washington; widespread in western North America from British Columbia south to California, east to the Rocky Mountains.
Habitat: Lowland riparian areas including streambanks and pond and lake margins.
Origin: Native
Flowers: April-June
Salix glaucagray willow
Origin: Native
var. villosa – glaucous willow, gray willow
Salix hookerianacoastal willow
Distribution: Chiefly west of the Cascades in Washington; British Columbia south to California.
Habitat: Moist, often swamps areas, from the sea coast to mid-elevations in the mountains.
Origin: Native
Flowers: March-April
Salix lasiandraPacific willow
Distribution: Widely distributed throughout Washington; Alaska south to California, east to Manitoba and New Mexico.
Habitat: Riparian areas from the coast to the mountains.
Origin: Native
Flowers: March-June
var. caudata – gland willow, Pacific willow, shining willow
var. lasiandra – Pacific willow
Salix lasiolepisarroyo willow
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Idaho, south to the southern Rocky Mountains and Texas.
Habitat: Riparian corridors from low to moderate elevations.
Origin: Native
Flowers: April-June
Salix maccallianaMaccalla's willow
Distribution: East of the Cascades in Washington; Yukon Territory south 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
Salix matsudanacorkscrew willow
Origin: Introduced
Salix melanopsisdusky willow
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south 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
Salix monochromaone-color willow
Origin: Native
Salix nivalisdwarf snow willow
Distribution: In the Olympic and Cascade mountains of Washington; British Columbia and Alberta, south to California, east to Colorado.
Habitat: Subalpine meadows and alpine areas.
Origin: Native
Flowers: June-August
Salix pedicellarisbog willow
Distribution: Chiefly in the Cascades of Washington; Yukon Territory south 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
Salix petrophilaalpine willow
Distribution: Northern Cascades of Washington; British Columbia south to California, east to the Rocky Mountains.
Habitat: Alpine areas, often near melting snowbanks.
Origin: Native
Flowers: July-Aug.
Salix planifoliaplane-leaf willow, tea-leaved willow
Distribution: Chiefly in the Cascade Mountains of Washington; widely distributed throughout western North America and across northern half of North America to the Atlantic Coast.
Habitat: Wet meadows, lake margins, streambanks and other riparian areas in the alpine and subalpine.
Origin: Native
Flowers: May-July
var. planifolia – diamondleaf willow
Salix prolixaMackenzie's willow
Distribution: Widely distributed throughout Washington; British Columbia to California, east to Newfoundland and Virginia.
Habitat: Along streams in the lowlands to lower valleys in the mountains.
Origin: Native
Flowers: April-June
Salix pseudomonticolafalse mountain willow
Distribution: Chiefly in the Cascade Mountains in Washington; Alaska to Washington, east to Quebec.
Habitat: Wet meadows, forested wetlands, and other riparian areas in the mountains.
Origin: Native
Flowers: April-June
Salix purpureapurple osier, basket willow, purple willow
Origin: Introduced
Salix scoulerianaScouler's willow
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Moist woods and streambanks, lowlands to moderate elevations in the mountains.
Origin: Native
Flowers: March-June
Salix ×sepulcralisweeping willow
Origin: Introduced
Salix sessilifoliasessile-leaf willow
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to Oregon.
Habitat: Riparian corridors at low to moderate elevations.
Origin: Native
Flowers: May-July
Salix sitchensisSitka willow
Distribution: Occurring in forested areas on both sides of the Cascades crest in Washington; Alaska to California, east to western Montana.
Habitat: Moist woods and stream banks, lowlands to moderate elevations in the mountains.
Origin: Native
Flowers: April-June
var. sitchensis – Sitka willow
Salix tweedyiTweedy's willow
Distribution: Chiefly North Cascade Mountains in Washington; British Columbia south to Washington, east to Montana, Idaho and Wyoming.
Habitat: Wet meadows, lake margins, streambanks, and other riparian areas in alpine and subalpine.
Origin: Native
Flowers: July-August
Salix vestitarock willow
Distribution: North Cascade Mountains in Washington; British Columbia south to Oregon, east across northern North America to the Canadian Maritime Provinces.
Habitat: Moist forest opening, streambanks, and other riparian areas in montane and subalpine habitats.
Origin: Native
Flowers: June-July
Salsola tragusRussian thistle, tumbleweed
Distribution: Occurring chiefly east of the Cascades crest in Washington, where widely distributed; southern British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Roadside, meadows, fields, wastelots, and other disturbed open areas from low to middle elevations.
Origin: Introduced from Eurasia
Flowers: June-August
Salvia aethiopisAfrican sage
Distribution: Introduced from the Mediterranean region to southwest United States, spreading north to eastern Oregon.
Habitat: A weed of dry waste places and roadsides.
Origin: Introduced from Europe
Flowers: June - July
Salvia dorriigray ball sage, purple sage
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Utah and Arizona.
Habitat: Dry, open, often sandy or rocky areas in sagebrush plains and foothills.
Origin: Native
Flowers: May-July
var. incana – fleshy sage, gray-ball sage
Salvia nemorosaBalkan clary
Origin: Introduced from Eurasia
Salvia pratensismeadow clary, prairie-meadow sage
Distribution: Scattered locations on both sides of the Cascades in Washington; escaping in parts of western, central, and eastern North America.
Habitat: Roadsides and other disturbed habitats.
Origin: Introduced
Flowers: June-August
Salvia sclareacleareye
Distribution: Scattered locations on both sides of the Cascades in Washington; occasionally escaping in parts of western, central, and eastern North America.
Habitat: Roadsides and other disturbed areas.
Origin: Introduced
Flowers: June-August
Salvia virgatawand sage
Origin: Introduced from Europe
Sambucus ceruleablue elderberry
Distribution: Widely distributed on both sides of the Cascades crest in Washington; southern British Columbia to California, east to the Rocky Mountains.
Habitat: Forest edge, fields, and roadsides from near sea level to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Sambucus nigrablack elderberry
Distribution: Uncommon west of the Cascades crest in Washington; southern British Columbia to northern Oregon; eastern North America where S. nigra var. canadensis is native. and var. nigra is more frequently escaped.
Habitat: Disturbed areas where rarely escaping from nearby cultivation.
Origin: Introduced from Europe and eastern North America
Flowers: May-July
Sambucus racemosared elder
Distribution: Widely distributed throughout much of Washington; ranging throughout the United States and Canada, except the southern States.
Habitat: A wide variety of areas, typically in forests, fields, and wet areas.
Origin: Native
Flowers: March-July
var. arborescens – coast red elderberry
var. melanocarpa – black elderberry
Samolus parvifloruswater pimpernel
Distribution: Occurring west of the Cascades crest along the Lower Columbia River in southwestern Washington; southwestern Washington to adjacent northwestern Oregon, otherwise in California, east across the southern U.S. to eastern North America.
Habitat: Freshwater intertidal zone.
Origin: Native
Flowers: July-September
Sandbergia perplexapuzzling halimolobos
Distribution: Known from Douglas County in Washington; Washington east toIdaho and Montana.
Habitat: Sagebrush desert, typically on lithosol.
Origin: Native
Flowers: April-June
Sandbergia whitediifissurewort, whited's halimolobos fissurewort
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to Washington.
Habitat: Dry scabland, forest openings, talus slopes and alpine meadows.
Origin: Native
Flowers: April-July
Sanguisorba menziesiiMenzies' burnet, small-head burnet
Origin: Native
Flowers: July - August
Sanguisorba officinalisgarden burnet, great burnet
Distribution: Alaka to northwest California, chiefly along the coast, inland to Mt. Hood, Oregon, where up to 5000 feet.
Habitat: Muskeg, swamps, and bogs.
Origin: Native
Flowers: July - August
Sanguisorba stipulataSitka burnet
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska south to Oregon, east to Idaho in the west, and Illimois to Maine, south to Alabama in the east.
Habitat: Wet places at mid-elevations in the mountains.
Origin: Native
Flowers: July-August
Sanicula arctopoidesfootsteps-of-spring, bear's-foot sanicle
Distribution: Occurring west of the Cascades crest along the coast in Washington; Vancouver Island, B.C. south along the coast to California.
Habitat: Maritime species of coastal bluffs, meadows, and balds.
Origin: Native
Flowers: March-May
Sanicula bipinnatifidapurple black-snakeroot, purple sanicle
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California.
Habitat: Balds, forest edge, and other open to partially shaded areas at low to moderate elevations.
Origin: Native
Flowers: May-June
Sanicula crassicaulisPacific sanicle
Distribution: Occurring west of the Cascades crest and east in the Columbia River Gorge in Washington; British Columbia to California.
Habitat: Meadows, balds, prairies, and open woods from the coast to low elevations in the mountains.
Origin: Native
Flowers: April-June
var. crassicaulis – Pacific sanicle
var. tripartita – Pacific sanicle
Sanicula graveolensSierran black-snakeroot
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Montana and Wyoming.
Habitat: Common in open woods, balds, and thickets at low to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Sanicula marilandicaMaryland black-snakeroot
Distribution: Occurring east of the Cascades crest in the northeastern counties in Washington; Eastern British Columbia to northeast Washington, east to the Atlantic coast.
Habitat: Moist, low ground, less often on moist, wooded slopes.
Origin: Native
Flowers: May-June
Saponaria ocymoidesrock soapwort
Distribution: Garden plant, occasionally escaping but rarely persistent, in the Pacific Coast states and a few states in eastern United States.
Habitat: Old gardens, waste sites and rocky places.
Origin: Introduced from Europe
Flowers: June - July
Saponaria officinalisbouncing-bet
Distribution: Introduced throughout the United States; found on both sides of the Cascades in Washington.
Habitat: Roadsides and waste ground
Origin: Introduced from Europe
Flowers: July - September
Sarcobatus vermiculatusgreasewood
Distribution: East of the Cascade in Washington; Washington south to California, east to the Dakotas, south to Colorado.
Habitat: Saline or alkaline, usually heavy soils of the drier regions.
Origin: Native
Flowers: May-July
Sarracenia flavayellow pitcher plant, yellow trumpet
Distribution: Native in southeastern United States; introduced in western Washington.
Habitat: Swamps, bogs and seeps.
Origin: Introduced from southeast United States
Flowers: May - June
Sarracenia leucophyllawhite-topped pitcher plant
Origin: Introduced from southeast United States
Sarracenia purpurea
Origin: Introduced
ssp. purpurea – northern pitcher plant, purple pitcher plant
Sasa palmatabroadleaf bamboo
Distribution: Occurring in the Puget Sound lowlands in Washington; also known from Tennessee.
Habitat: Disturbed lowland areas where escaping from cultivation.
Origin: Introduced
Saussurea americanaAmerican sawwort
Distribution: Occurring in the Olympics and Cascades mountains in Washington; Yukon Territory to California, east to Alberta, Montana, and Idaho.
Habitat: Meadows and open, often rocky slopes, where moist, at mid- to high elevations in the mountains.
Origin: Native
Flowers: July-September
Saxifraga adscendenswedge-leaf saxifrage
Distribution: Occurring on both sides of the Cascades crest in northern Washington and possibly in the Olympic Mountains; Alaska to Nevada, east to the Rocky Mountains.
Habitat: Glacial moraines and alpine gravelly meadows.
Origin: Native
Flowers: June-August
Saxifraga austromontanamatted saxifrage, spotted saxifrage
Distribution: Alaska to Greenland, south in the Cascades to Oregon, and in the Rockies to New Mexico
Habitat: Cliff crevices, talus and scree slopes, mid- to high elevations in the mountains
Origin: Native
Flowers: June-August
Saxifraga cernuanodding saxifrage
Distribution: Known only east of the Cascades crest in north-central Washington; Alaska south to California, east to the Rocky Mountains and across northern Canada to the Atlantic Coast.
Habitat: Among rocks in alpine areas, often where moist.
Origin: Native
Flowers: July-September
Saxifraga cespitosatufted alpine saxifrage, tufted saxifrage
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to south California, east to the Rocky Mountains; east across Canada to the Atlantic Coast.
Habitat: Ledges, gravelly ridges and scree, near sea level to alpine.
Origin: Native
Flowers: April-September
Saxifraga hyperboreapygmy saxifrage
Distribution: In the Olympic and Cascade mountains of Washington; Alaska south to California, throughout the Rocky Mountains, across northern Canada to the Maritime Provinces.
Habitat: Alpine tundra, often where moist with rocky outcroppings, crevices, and snowmelt.
Origin: Native
Flowers: June-August
Saxifraga mertensianaMerten's saxifrage, woodland saxifrage
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Alberta, Idaho, and Montana.
Habitat: Wet ledges, shaded seeps on rock faces, and gravelly stream banks from sea level to the subalpine.
Origin: Native
Flowers: April-August
Saxifraga oppositifoliapurple saxifrage, twinflowered saxifrage
Distribution: In the Olympic and Cascade mountains of Washington; Alaska south to Oregon, east to the Rocky Mountains; across northern Canada and northeastern U.S.
Habitat: Alpine slopes and rocky outcroppings
Origin: Native
Flowers: June-August
ssp. oppositifolia – purple mountain saxifrage, purple saxifrage, twinflowered saxifrage
Saxifraga tridactylitesrue-leaved saxifrage
Origin: Introduced
Saxifraga vespertinamatted saxifrage, spotted saxifrage
Distribution: West of the Cascades crest in Washington; Washington south to Oregon.
Habitat: Rocky outcroppings.
Origin: Native
Flowers: June-August
Saxifragopsis fragarioidesstrawberry saxifrage
Distribution: Occurring east of the Cascades crest in the Wenatchee Mountains in Washington, where disjunct; southwestern Oregon to adjacent California.
Habitat: Rock outcrops and talus slopes at middle elevations.
Origin: Native
Flowers: June-August
Sceptridium multifidumleathery grapefern
Distribution: Occurring chiefly west of the Cascades crest and in the northeastern counties in Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Open or shaded places, including meadows, wetland margins, and forest edge, from low elevations to the subalpine.
Origin: Native
Schedonorus arundinaceustall fescue, tall rye grass
Distribution: Occurring on both sides of the Cascades crest in Washington; widely distributed throughout North America.
Habitat: Meadowlands, fallow fields an ditch banks.
Origin: Introduced
Flowers: May-July
Schedonorus pratensismeadow fescue, meadow rye grass
Distribution: Occurring in scattered localities on both sides of the Cascades crest in Washington; widely distributed throughout North America.
Habitat: Meadows, pastures, roadsides, and other disturbed areas, often where moist
Origin: Introduced
Flowers: May-July
Scheuchzeria palustrisscheuchzeria
Distribution: Southern Alaska south to northern California, east to Labrador and New Jersey.
Habitat: In bogs or on lake margins.
Origin: Native
Flowers: May - July
Schizachyrium scopariumbroom bluestem, little bluestem
Distribution: Alberta east to Quebec, south through most of the United States east of the rockies; sparingly introduced in the Pacific Northwest.
Habitat: Prairies and foothills.
Origin: Native?
Flowers: July - August
var. scoparium – broom beardgras, broom bluestem, little bluestem
Schoenoplectus acutushardstem bulrush, viscous bulrush, common tule
Distribution: Both sides of the Cascades in Washington; throughout all of North America except southeastern U.S.
Habitat: Pond and lake margins, wetland and riparian areas.
Origin: Native
Flowers: May-July
Schoenoplectus americanusOlney's three-square bulrush
Origin: Native
Schoenoplectus heterochaetusslender bulrush
Origin: Native
Schoenoplectus ×kuekenthalianusKukenthal's bulrush
Origin: Native
Schoenoplectus mucronatusricefield bulrush, rough-seed bulrush
Origin: Introduced
Schoenoplectus pungenschairmaker's clubrush, common three square
Distribution: Occurring on both sides of the Cascades crest in Washington; widespread throughout North America.
Habitat: Marshes and wet, low ground; tolerent of alkali.
Origin: Native
Flowers: May-August
Schoenoplectus saximontanusRocky Mountain bulrush
Origin: Native
Schoenoplectus subterminalisswaying clubrush, water clubrush
Distribution: Chiefly west of the Cascades, southern Alaska to southern Oregon; also in northern Idaho, northwest Montana, and eastern United States.
Habitat: Quiet, shallow water 2-8 dm. deep,
Origin: Native
Flowers: July - August
Schoenoplectus tabernaemontanigreat bulrush, soft-stem bulrush
Distribution: Widespread in temperate North America; common throughout the Pacific Northwest, but less so than S. acutus.
Habitat: Marshes and muddy shores of lakes and streams at lower elevations; tolerant of alkali.
Origin: Native
Flowers: June - August
Schoenoplectus triqueterstream bank bulrush, triangular club-rush
Distribution: Occurring west of the Cascades crest in Washington in the lower Columbia River; southwestern Washington to adjacent northwestern Oregon.
Habitat: Freshwater intertidal zone.
Origin: Introduced from Eurasia
Flowers: July-September
Scirpus atrocinctuscommon woolly sedge
Distribution: Known only from Whatcom County in Washington; British Columbia south to Washington, east across the northern half of North America to the Atlantic Coast.
Habitat: Wet, low ground.
Origin: Native
Flowers: July-August
Scirpus cyperinuscottongrass bulrush
Distribution: Newfoundland south to Florida, occasionally west across southern Canada to southeast British Columbia and northern Washington.
Habitat: Wet, low ground.
Origin: Introduced
Flowers: July-August
Scirpus microcarpuspanicled bulrush, small fruited bulrush
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east in Canada and northern United States to New England.
Habitat: Wet ground, ditches, shorelines, streambanks, and other riparian areas from low to moderate elevations in the mountains
Origin: Native
Flowers: June-August
Scirpus palliduspale bulrush
Distribution: Southest Washington and northeast Oregon, east to Utah, Minnisota and Texas.
Habitat: Wet, low ground, from the lowlands to moderate elevations in the mountains.
Origin: Native
Flowers: June - August
Scleranthus annuusannual knawel
Distribution: Occasional introductions throughout the Pacific Northwest
Habitat: Disturbed soils, waste lots, cultivated areas.
Origin: Introduced from Europe
Flowers: April-July
Sclerochloa duracommon hard grass
Distribution: Sparingly introduced in much of western United States; established in eastern Washington and Oregon.
Habitat: Weed of waste areas.
Origin: Introduced
Flowers: June
Sclerolinon digynumnorthwestern yellow-flax
Distribution: East of the Cascades in Washington; Washington south to the Sierra Nevada of California, east to Idaho.
Habitat: Meadows and prairies at low to moderate elevations.
Origin: Native
Flowers: May-July
Scleropoa rigidafern grass
Origin: Introduced
Flowers: June - July
Scribneria bolanderiScribner's grass
Origin: Native
Flowers: April - May
Scrophularia californicaCalifornia figwort, Oregon figwort
Distribution: Occurring west of the Cascades crest in Washington, chiefly in coastal counties; coastal southwestern British Columbia to California.
Habitat: Forest margins, prairies, and meadows at low elevations.
Origin: Native
Flowers: May-July
Scrophularia lanceolatalance-leaf figwort
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across much of the U.S. and all of Canada to the Atlantic Coast.
Habitat: Moist forest edges and openings, and meadows at low elevations, but not along the coast.
Origin: Native
Flowers: June-August
Scutellaria angustifolia
Distribution: East of the Cascades in Washington; British Columbia south to Oregon, southeast to Idaho, Nevada and Utah.
Habitat: Moist and drier sites, moderate to mid-elevations in the mountains.
Origin: Native
Flowers: May-July
ssp. angustifolia – narrow-leaved skullcap
ssp. micrantha – small-flowering narrow-leaved skullcap
Scutellaria galericulatahooded skullcap, marsh skullcapp
Distribution: Both sides of the Cascades in Washington; circumboreal, extending south to California, Arizona and Missouri.
Habitat: Wet meadows and similar habitats at moderate elevations.
Origin: Native
Flowers: June-August
Scutellaria laterifloramadweed, mad-dog skullcap
Distribution: Both sides of the Cascades in Washington; occurring throughout North America.
Habitat: Moist bottomlands and meadows, low to moderate elevations.
Origin: Native
Flowers: July-September
Secale cerealecultivated rye
Distribution: Widely cultivated, especially in poor, dry soil, often persistent for more than one season.
Habitat: Roadsides and waste ground.
Origin: Introduced
Flowers: May - July
Secale strictum
Origin: Introduced
Securigera variacrown vetch, purple crown vetch
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east across North America.
Habitat: Roadsides, fields, wastelots, and other disturbed areas.
Origin: Introduced from Eurasia
Flowers: June-August
Sedum acremossy stonecrop
Distribution: Occurring chiefly west of the Cascades in Washington; British Columbia south to Oregon, east across Canada, and the central, southeastern, and northeastern U.S. to the Atlantic Coast.
Habitat: Disturbed ground at low elevation.
Origin: Introduced from Europe
Flowers: June-August
Sedum albumwhite stonecrop
Distribution: Occurring in scattered locations across Washington; British Columbia south to California, Utah, and in northeastern North America.
Habitat: Disturbed, open areas including fields, lawns, parking areas, and rocky outcroppings.
Origin: Introduced
Flowers: May-July
Sedum brevifoliumshort-leaved stonecrop
Origin: Introduced from southern Europe
Sedum divergensPacific stonecrop, spreading stonecrop
Distribution: Alaska to California, Olympic mountains and the Cascades
Habitat: Open, rocky areas, mid- to high elevations in the mountains
Origin: Native
Flowers: July - Early September
Sedum forsterianumForster's stonecrop
Origin: Introduced
Sedum lanceolatumlance-leaved stonecrop
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains and northern Great Plains in the U.S. and Canada.
Habitat: On rocks or gravel in open, dry areas, from sea level to the alpine.
Origin: Native
Flowers: May-August
Sedum leibergiiLeiberg's stonecrop
Distribution: Yakima County, Washington, south to northcentral Oregon and east to southeast Washington and western Idaho; along the Snake River.
Habitat: Mossy rocks to open, gravelly hillsides, chiefly in canyons.
Origin: Native
Flowers: May - Early July
Sedum oreganumOregon stonecrop
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California.
Habitat: Rock ledges, talus slopes and gravelly ridges from low elevations to the subalpine.
Origin: Native
Flowers: June-August
Sedum rupicolalance-leaved stonecrop
Distribution: In the Cascades and Olympic Mountains of Washington; Washington east to Idaho.
Habitat: Open, exposed places, usually on rocks or in gravelly soil, at moderate elevations in the mountains.
Origin: Native
Flowers: June-August
Sedum spathulifoliumbroadleaf stonecrop, spatula-leaf stonecrop
Distribution: Occurring west of the Cascades crest and east in the Columbia River Gorge in Washington; southern British Columbia to California.
Habitat: Coastal cliffs, ledges, balds, and gravelly soil in the foothills.
Origin: Native
Flowers: April-June
Sedum stenopetalumwormleaf stonecrop
Distribution: Occurring chiefly east of the Cascade crest in Washington; British Columbia south to California, east to the northern Rocky Mountains.
Habitat: Grasslands and ponderosa pine forests to sub-alpine ridges, on dry, gravelly benches, rock crevices and talus.
Origin: Native
Flowers: May-July
ssp. stenopetalum – wormleaf stonecrop
Sedum thartii
Origin: Introduced
Selaginella douglasiiDouglas' spikemoss clubmoss, lesser clubmoss
Distribution: Abundant in the Columbia River Gorge, especially on the Oregon side, west along the river to Portland, OR, and Cowlitz County, WA; also along the Clearwater River in Idaho.
Habitat: Cliffs, banks and tree trunks in humid regions at low elevations
Origin: Native
Selaginella oreganafestoon spikemoss, Oregon spikemoss
Origin: Native
Selaginella scopulorumcliff spikemoss, Rocky Mountain spikemoss
Origin: Native
Selaginella wallaceiWallace's spikemoss
Distribution: British Columbia through central Oregon to California, east to Montana
Habitat: Exposed, terrestrial, often rocky sites, such as pocket of soil in ledges and cliffs
Origin: Native
Senecio elmeriElmer's ragwort
Distribution: Occurring on both sides of the Cascades crest in central and northern Washington; British Columbia to central Washington.
Habitat: Talus slopes and other rocky places in alpine areas.
Origin: Native
Flowers: July-September
Senecio fremontiidwarf mountain butterweed
Distribution: Occurring on both sides of the Cascades crest and in the Olympic Mountains in Washington; British Columbia to California, east to Alberta, Montana, Wyoming, and Utah.
Habitat: Open, rocky slopes at high elevations in the mountains
Origin: Native
Flowers: July-September
var. fremontii – dwarf mountain groundsel
Senecio hydrophiloidessweet marsh butterweed, stout meadow groundsel
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, Wyoming, and Utah.
Habitat: Wet meadows in the mountains and foothills, but not in alkali.
Origin: Native
Flowers: May-July
Senecio hydrophilusalkali marsh butterweed, water groundsel, alkali marsh ragwort
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Swampy places in the valleys and foothills; tolerant of alkali.
Origin: Native
Flowers: June- September
Senecio integerrimusone-stemmed butterweed, western groundsel
Distribution: Occurring chiefly east of the Cascades crest in Washington, where widely distributed; British Columbia to California, east to the Great Plains and Great Lakes region.
Habitat: Meadows and seasonally moist open areas from low elevations to the subalpine.
Origin: Native
Flowers: May-August
var. exaltatus – one-stemmed butterweed, lambs-tongue groundsel, tall western groundsel
var. ochroleucus – white western groundsel
Senecio lugensblack-tipped groundsel
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to Washington, east to the northern Rocky Mountains.
Habitat: Wet meadows, grassy alpine slopes, and rich northern woods.
Origin: Native
Flowers: June-August
Senecio neowebsteriOlympic Mountain ragwort
Distribution: Occurring west of the Cascades crest, where endemic to the Olympic Mountains of Washington.
Habitat: Talus slopes and rocky places.
Origin: Native
Flowers: Aug.-Sept.
Senecio serratall butterweed, butterweed groundsel
Distribution: Occurring chiefly east of the Cascades crest in Washington; Washington to California, east to Montana, Wyoming, and Colorado.
Habitat: Meadows and open, moist hillsides, foothills to mid-elevations in the mountains.
Origin: Native
Flowers: June-August
var. serra – tall butterweed, butterweed groundsel
Senecio sylvaticuswood groundsel, woodland groundsel, woodland ragwort
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California, also in eastern North America.
Habitat: Roadsides, fields, forest edge, wastelots, and other disturbed areas at low elevation.
Origin: Introduced from Europe
Flowers: May-September
Senecio triangularisarrowleaf groundsel, arrowleaf ragwort
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains.
Habitat: Moist places and streambanks from the lowlands to the subalpine.
Origin: Native
Flowers: June-September
var. triangularis – arrowleaf groundsel, arrowleaf ragwort
Senecio viscosussticky ragwort
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to Washington, east across Canada to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed areas at low elevations.
Origin: Introduced from Eurasia
Flowers: June-September
Senecio vulgariscommon groundsel, old man in the spring
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: Roadsides, waste ground, lawns, and other disturbed, open sites.
Origin: Introduced from Europe
Flowers: February-May
Sericocarpus oregonensisOregon white-topped aster
Distribution: Occurring in the Columbia River Gorge in Washington; Washington to California.
Habitat: Grasslands, forest openings, and savanna.
Origin: Native
Flowers: July-September
ssp. oregonensis – Oregon white-topped aster
Sericocarpus rigidusColumbian white-topped aster, Columbian whitetop aster, rigid white-topped aster
Distribution: Occurring west of the Cascades crest in lowland Washington; southern Vancouver Island to southwest Oregon.
Habitat: Prairies and open areas at low elevations.
Origin: Native
Flowers: July-August
Setaria faberiChinese foxtail
Origin: Introduced from China
Setaria italicaItalian bristlegrass, foxtail millet
Origin: Introduced from China
Setaria pumila
Origin: Introduced
ssp. pallide-fusca – yellow foxtail, pigeon grass
ssp. pumila – yellow foxtail
Setaria verticillatahooked bristlegrass, rough bristlegrass
Distribution: Sparingly introduced in the Pacific Northwest; more common in other parts of the United States.
Habitat: Weed of gardens, irrigated areas and wasteland.
Origin: Introduced from Europe
Flowers: August - September
Setaria viridis
Distribution: Widely distributed throughout much of Washington; widely distributed throughout much of North America.
Habitat: Disturbed soil and wasteland.
Origin: Introduced from Eurasia
Flowers: June-October
var. viridis – green bristlegrass
Shepherdia canadensisrusset buffalo-berry, soapberry, soopolallie
Distribution: Both sides of the Cascades in Washington; Alaska to Oregon, east to the Atlantic Coast.
Habitat: Moderately dry, open to wooded areas, sea level to mid-elevations in the mountains.
Origin: Native
Flowers: May-July
Sherardia arvensisblue field-madder
Distribution: Chiefly west of the Cascades in Washington; British Columbia south to California, east to Idaho and Arizona; introduced from Michigan to Maine, south to Texas to Florida in the east.
Habitat: Weed of prairies, meadows, and other open, disturbed areas.
Origin: Introduced from Mediterranean
Flowers: April-July
Sibbaldia procumbenscreeping-glow-wort, creeping sibbaldia
Distribution: Occurring on both sides of the Cascades crest in Washington; widely distributed throughout western North America and northeastern North America; circumboreal.
Habitat: Open, dry to moist subalpine and alpine slopes.
Origin: Native
Flowers: June-August
Sidalcea campestrismeadow checker-mallow, meadow sidalcea
Distribution: Native only to the Willamette Valley area (Multnomah and Washington to Benton and Linn counties). Introduced as a garden plant in western Washington, but rarely persisting.
Habitat: Dry fields and roadsides.
Origin: Introduced
Flowers: May-July
Sidalcea hendersoniiHenderson's checker-mallow
Distribution: Occurring west of the Cascades crest in the coastal counties in Washington; southwestern British Columbia to the Umpqua River area in Oregon.
Habitat: On or adjacent to tidelands, coastal marshes.
Origin: Native
Flowers: June-August
Sidalcea hirtipesbristly-stem checker-mallow
Distribution: Clark and Lewis counties in Washington; south to Lincoln, Tillamook and Clatsop Counties, Oregon.
Habitat: Coastal mountains to bluffs along the ocean, but not on tideflats.
Origin: Native
Flowers: June-July
Sidalcea nelsonianaNelson's checker-mallow
Distribution: Occurring in southwest Washington; south in Willamette Valley of Oregon from Portland to Salem, west to Tillamook County.
Habitat: Gravelly, well-drained soil at low elevations.
Origin: Native
Flowers: May-July
Sidalcea oreganaOregon checker-mallow
Distribution: Chiefly east of the Cascades in Washington; Washington south to California, east to Wyoming.
Habitat: Sagebrush plains, meadows and ponderosa pine forests.
Origin: Native
Flowers: May-July
var. calva – Oregon checkermallow
var. oregana – Oregon checkermallow
Sidalcea virgatavirgate checkerbloom
Distribution: Known only from Thurston County in Washington; Thurston County, WA and then Yamhill County, Oregon south along West Cascades to California.
Habitat: Moist prairies and meadows at low elevations.
Origin: Native
Flowers: April-June
Silene acaulismoss campion
Distribution: Alaska to Oregon, and south in the Rocky Mountains to Arizona
Habitat: Rock crevices and talus slopes at high elevations in the mountains
Origin: Native
Flowers: June - August
Silene antirrhinasleepy catchfly
Distribution: Distributed widely throughout Washington; occurring across North America from low elevations to 10,000 feet.
Habitat: Open areas, often where disturbed.
Origin: Native
Flowers: May-August
Silene bernardinaPalmer's catchfly
Distribution: Occurring east of the Cascades crest in Yakima County, where disjunct; Lane County, Oregon to California, Nevada, and Mexico, east to western Idaho; disjunct in Yakima County, WA.
Habitat: Grassy slopes to ponderosa pine forest openings at middle elevations.
Origin: Native
Flowers: May-June
Silene conicasand catchfly
Origin: Introduced from Eurasia
Flowers: May - July
Silene conoideaconoid catchfly
Origin: Introduced from Europe
Flowers: May - July
Silene csereiibiennial campion
Distribution: Occurring in scattered locations east of the Cascades crest in Washington; British Columbia south to Washington, east across the central and northern U.S. and Canada to the Atlantic Coast.
Habitat: Disturbed areas including fields, roadsides, and wastelots.
Origin: Introduced
Flowers: June-August
Silene dichotomaforked catchfly
Origin: Introduced from Europe
Flowers: May - July
Silene dioicared catchfly
Distribution: Occurring in scattered locations in lowland western Washington; British Columbia south to Oregon, east to eastern North America.
Habitat: Disturbed areas, roadsides, and wastelots where escaped from cultivation.
Origin: Introduced from Europe
Flowers: June-August
Silene douglasiiDouglas's silene
Distribution: Widely distributed throughout most of Washington; British Columbia south to California, east to the Rocky Mountains.
Habitat: Sagebrush plains to mountain slopes.
Origin: Native
Flowers: May-July
var. douglasii – Douglas's catchfly
var. rupinae – Douglas's catchfly
Silene flos-cuculiragged-robin
Origin: Introduced
Silene gallicawindmill-pink
Distribution: Occurring in the lowlands west of the Cascades crest in Washington; British Columbia south to California, east to Idaho and Arizona; also in the eastern half of the U.S.
Habitat: Weed of disturbed soil and wasteland.
Origin: Introduced from Europe
Flowers: May-July
Silene latifoliawhite campion, evening catchfly
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: Roadsides, fields, meadows, pastures, irrigation ditches, forest edge, thickets, wastelots, and other disturbed open areas, often where moist.
Origin: Introduced from Europe
Flowers: May-August
Silene menziesiiMenzies' catchfly
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska south to California, east to Montana and New Mexico.
Habitat: Common in open woods from the lowlands to moderate elevations in the mountains.
Origin: Native
Flowers: May-August
Silene noctifloranight-flowering catchfly
Distribution: Introduced in much of the United States; more common east of the Cascades in Washington.
Habitat: Grain fields and waste areas.
Origin: Introduced from Europe
Flowers: June - August
Silene oreganaOregon catchfly
Distribution: Occurring chiefly east of the Cascades crest in Washington; Washington to California, east to the Rocky Mountains of Montana and Wyoming, and to northeastern Nevada.
Habitat: Forest openings and meadows from middle elevation to subalpine.
Origin: Native
Flowers: June-August
Silene paradoxa
Origin: Introduced
Silene parryiParry's silene
Distribution: Widely distributed across Washington; Alaska south to Oregon, east in the mountains to Montana and Utah.
Habitat: Open areas, mid- to high elevations in the mountains.
Origin: Native
Flowers: July-August
Silene scouleri
Distribution: Occuring in localities on both sides of the Cascades in Washington; British Columbia south to California, east to the Rocky Mountains.
Habitat: Prairies and open timberland, low to moderate elevations.
Origin: Native
Flowers: June-August
ssp. hallii – Hall's catchfly
ssp. scouleri – Scouler's silene
Silene seelyiSeely's silene
Distribution: Wenatchee Mountains, Kittitas and Chelan Counties, Washington.
Habitat: Cliffs and talus slopes at moderate to mid-elevations in the mountains.
Origin: Native
Flowers: Late May - August
Silene spaldingiiSpalding's silene
Distribution: Occurring in southeastern counties of Washington; southeastern Washington to adjacent northeastern Oregon and western Idaho, also in western Montana.
Habitat: Sagebrush, scabland and ponderosa pine forests.
Origin: Native
Flowers: June-July
Silene suksdorfiiCascade catchfly
Distribution: Occurring in the Cascades Mountains in Washington; from Mt. Baker, Washington area south to northern California.
Habitat: Alpine and subalpine slopes, often on talus.
Origin: Native
Flowers: June-August
Silene vulgarisbladder campion
Distribution: Occurring in many areas throughout Washington; widely distributed throughout North America except along the southern areas of the U.S.
Habitat: Weed of waste ground, usually at lower elevations.
Origin: Introduced from Europe
Flowers: June-August
Silybum marianummilk-thistle
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east across Canada and the southwestern U.S. to eastern North America.
Habitat: Roadsides, fields, wastelots, and other disturbed areas.
Origin: Introduced from the Mediterranean region
Flowers: May-July
Sinapis albawhite mustard
Distribution: Reported from Whitman County in Washington; widely distributed throughout North America.
Habitat: Waste ground near fields.
Origin: Introduced from the Mediterranean region
Flowers: May-June
Sinapis arvensischarlock, corn mustard, wild mustard
Distribution: Occurring in scattered locations throughout Washington; widely distributed throughout North America.
Habitat: Waste places and other disturbed areas.
Origin: Introduced from the Mediterranean region, reaching North America perhaps as early as 8000 years bp (Jacobson et al. 1988)
Flowers: May-June
Sisymbrium altissimumJim Hill mustard, tumble mustard, tall rocket
Distribution: Distributed throughout Washington but more common east of the Cascades; occurring throughout North America.
Habitat: Shrub-steppe, grasslands, and waste ground, especially following rangeland fires.
Origin: Introduced from Eurasia
Flowers: May-September
Sisymbrium linifoliumlava cress, rush mustard, flax-leaved plainsmustard, Salmon River plainsmustard
Distribution: East of the Cascades crest in Washington; British Columbia south to Arizona (not including California), east to the Rocky Mountains.
Habitat: Sagebrush-steppe communities, rock crevices.
Origin: Native
Flowers: April-June
Sisymbrium loeseliifalse london rocket, Loesel's tumblemustard
Distribution: Occurring east of the Cascades in Washington; British Columbia south to Nevada, east to the Atlantic Coast.
Habitat: Roadsides and drier disturbed areas.
Origin: Introduced from Eurasia
Flowers: June-August
Sisymbrium officinalehedge mustard
Distribution: Occurring chiefly west of the Cascades crest in Washington; widely distributed throughout much of North America.
Habitat: Waste ground and other disturbed areas at low elevations.
Origin: Introduced from Europe
Flowers: March-September
Sisymbrium orientaleIndian hedgemustard
Origin: Introduced
Sisyrinchium californicumgolden-eyed grass
Distribution: Chiefly west of the Cascades in Washington; southern Vancouver Island, B.C, south to southern California.
Habitat: Wet ground, especially at the edges of lakes and bogs, at low to moderate elevations.
Origin: Native
Flowers: June-July
Sisyrinchium idahoenseIdaho blue-eyed grass
Distribution: Widely distributed across Washington; British Columbia to California, east to Montana and New Mexico.
Habitat: Vernally wet areas and marshes, near sea level to mid-elevations in the mountains.
Origin: Native
Flowers: April-July
var. idahoense – Idaho blue-eyed grass
var. macounii – Macoun's blue-eyed grass
var. occidentale – western blue-eyed grass
var. segetum – cornfield blue-eyed grass, prairie grass
Sisyrinchium littoraleAlaska blue-eyed grass, shore grass
Distribution: Occurring west of the Cascades crest in coastal areas in Washington; Alaska to Oregon
Habitat: Coastal moist, sandy or grassy areas, interdunal depressions, edges of streams and lakes
Origin: Native
Flowers: May-July
Sisyrinchium montanumstrict blue-eyed grass
Distribution: Occurring east of the Cascades crest in north-central Washington; Yukon Territory to Washington, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Moist meadows, stream banks, and for openings at low to middle elevations.
Origin: Native
Flowers: May-July
Sisyrinchium sarmentosumpale grass, Suksdorf's blue-eyed grass
Distribution: In the Cascade Mountains of Washington and Oregon near the Columbia River Gorge.
Habitat: Moist, grassy areas.
Origin: Native
Flowers: June-August
Sisyrinchium septentrionalenorthern blue-eyed grass
Distribution: Occurring in northeastern Washington; British Columbia east to Saskatchewan, south into northern Washington.
Habitat: Mesic to dry meadows and stream banks.
Origin: Native
Flowers: June-July
Sium suavewater parsnip, hemlock water-parsnip
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
Smelowskia americanaalpine smelowskia, Siberian smelowskia
Distribution: In the Olympic and Cascades mountains in Washington; British Columbia and Alberta south to Nevada, east to the Rocky Mountains.
Habitat: Rocky areas at high elevations in the mountains.
Origin: Native
Flowers: May-August
Smelowskia ovalisshort-fruited smelowskia
Distribution: In the Cascades Mountains in Washington; British Columbia south to California.
Habitat: Rocky crevices, moraines, ridges and talus slopes in alpine and sup-alpine regions.
Origin: Native
Flowers: June-August
Smilax glauca
Origin: Introduced
Solanum americanumAmerican black nightshade
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east along the southern border of the U.S. to the Atlantic Coast.
Habitat: Disturbed open areas, roadsides, waste ground.
Origin: Introduced from Europe
Flowers: July-September
Solanum carolinensehorse nettle
Origin: Introduced
Solanum dulcamarafelonwort, bittersweet nightshade, climbing nightshade
Distribution: Widely distributed throughout Washington; widely distributed throughout North America.
Habitat: Thickets, clearings and open woods, usually in moist soil
Origin: Introduced from Eurasia
Flowers: May-September
Solanum elaeagnifoliumwhite horse nettle, silver-leaf nightshade
Origin: Introduced from Mexico and eastern United States
Solanum lycopersicumtomato
Distribution: Known from scattered locations in Whatcom and King counties in Washington; likely escaping as occasional waif anywhere where cultivated in North America.
Habitat: Sunny, moist, open, disturbed areas.
Origin: Introduced
Flowers: May-October
Solanum nigrumEuropean black nightshade
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; widely distributed throughout North America.
Habitat: Fields, roadsides and other disturbed sites, especially in moister areas; often in urban and suburban areas.
Origin: Introduced from Europe
Flowers: July-November
Solanum physalifoliumhairy nightshade
Origin: Introduced
var. nitidibaccatum – ground-cherry nightshade
Solanum rostratumbuffalo bur, horned nightshade
Distribution: Widely distributed throughout Washington, where it is considered a noxious weed; widely distributed throughout North America.
Habitat: Roadsides and other disturbed areas, often where dry.
Origin: Introduced from central US
Flowers: June-September
Solanum triflorumcut-leaf nightshade
Distribution: East of the Cascades in Washington; widespread throughout North America, except eastern U.S.
Habitat: Weedy native in fields and roadsides, often in undisturbed sites at low to moderate elevations.
Origin: Introduced
Flowers: July-August
Solanum tuberosumirish potato
Origin: Introduced from Europe
Solidago elongataCascade Canada goldenrod, West Coast goldenrod
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington to California.
Habitat: Sandy or gravelly open areas or thickets at low to middle elevations.
Origin: Native
Flowers: July-September
Solidago lepidawestern Canada goldenrod
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, and east across Canada to the Atlantic Coast.
Habitat: Dry to moist areas in meadows and riparian areas, from low to middle elevations.
Origin: Native
Flowers: July-October
var. lepida – western Canada goldenrod
var. salebrosa – Canada goldenrod, meadow goldenrod, Rocky Mountains Canada goldenrod
Solidago missouriensisMissouri goldenrod
Distribution: Occurring on both sides of the Cascades crest in Washington; central British Columbia to Oregon, east to the Rocky Mountains, Great Plains, and midwestern U.S.
Habitat: Rather dry, open places, from the valleys and plains to fairly high elevations in the mountains.
Origin: Native
Flowers: June-October
Solidago multiradiatanorthern goldenrod, Rocky Mountain goldenrod
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon, Nevada, and Arizona, east to the Rocky Mountains, Great Plains, Great Lakes region, and midwestern U.S.
Habitat: Mountain meadows and open slopes at high elevations
Origin: Native
Flowers: June-September
Solidago simplexsticky goldenrod
Distribution: Occurring west of the Cascades crest in Washington; Alaska to Oregon, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Open, slightly moist areas from coastal dunes to alpine meadows.
Origin: Native
Flowers: June-September
var. nana – dwarf goldenrod
var. simplex – sticky goldenrod
Soliva sessilislawn burrweed, common soliva, prickly soliva
Distribution: Occurring west of the Cascades crest in lowland western Washington; British Columbia to California, also in south-central and southeastern U.S.
Habitat: Disturbed areas, roadsides, and lawn areas at low elevations.
Origin: Introduced from South America
Flowers: March-June
Sonchus arvensisfield sow-thistle, perennial sow-thistle
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: Balds, prairies, forest edge, stream banks, roadsides, fields, and other disturbed open areas generally at low elevations, often where moist.
Origin: Introduced from Europe
Flowers: July-October
ssp. arvensis – corn sow-thistle, field sow-thistle, perennial sow-thistle
ssp. uliginosus – field sow-thistle, marsh sow-thistle, wet ground sow-thistle
Sonchus asperprickly sow-thistle, spiny leaf sow-thistle
Distribution: Occurring on both sides of the Cascades crest in Washington, but more common west of the crest; Alaska to California, east to the Atlantic Coast.
Habitat: Forest edge, balds, prairies, roadsides, ditches, wastelots, and other disturbed open areas at low elevations.
Origin: Introduced from Europe
Flowers: June-October
Sonchus oleraceuscommon sow-thistle
Distribution: Occurring on both sides of the Cascades crest in Washington, but more common west of the crest; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Forest edge, balds, prairies, roadsides, ditches, wastelots, and other disturbed open areas at low elevations.
Origin: Introduced from Europe
Flowers: June-October
Sorbaria kirilowiigian false spiraea, giant false spiraea
Origin: Introduced
Sorbaria sorbifoliafalse spiraea
Origin: Introduced
Sorbus aucupariaEuropean mountain-ash
Distribution: Introduced, commonly planted species, spread by birds, near habitations.
Habitat: Often in areas where it appears to be native.
Origin: Introduced
Flowers: May - June
Sorbus hybridaSwedish service-tree
Origin: Introduced
Sorbus intermediaSwedish whitebeam
Origin: Introduced
Sorbus scopulinaGreene's mountain ash, Cascade mountain-ash, western mountain-ash
Distribution: Alaska south to California, east to the Dakotas and Colorado.
Habitat: Open areas, from the foothils to sub-alpine.
Origin: Native
Flowers: May - Early July
Sorbus sitchensismountain ash
Distribution: In the mountains on both sides of the Cascades and Olympic Mountains in Washington; Alaska south to northern California, east to Idaho and Montana.
Habitat: Forest openings at mid- to high elevations in the mountains.
Origin: Native
Flowers: June-July
var. grayi – Sitka mountain-ash
var. sitchensis – Sitka mountain-ash
Sorghum bicolorsorghum
Origin: Introduced from Africa
Sorghum halepenseJohnson grass
Distribution: Introduced and established in much of the United States; rarely persistent in the Pacific Northwest.
Habitat: Waste ground, especially where moist.
Origin: Introduced from Mediterranean
Flowers: July - October
Sparganium angustifoliumfloating bur-reed, narrow-leaved bur-reed
Distribution: Widely distributed in much of Washington; Alaska south to California, east to the Rocky Mountain states.
Habitat: Ponds and shallow lakes at moderate elevations in the mountains.
Origin: Native
Flowers: July-September
Sparganium emersumsimplestem bur-reed
Distribution: Alaska south to California, east to Colorado.
Habitat: Shallow ponds and marshes.
Origin: Native
Flowers: June - September
Sparganium eurycarpumbroadfruited bur-reed
Distribution: British Columbia to Baja, California, east to Newfoundland and Florida.
Habitat: Wet meadows to shallow marshes, mostly emersed.
Origin: Native
Flowers: May - October
Sparganium fluctuansfloating bur-reed, water bur-reed
Origin: Native
Sparganium natansarctic bur-reed, small bur-reed
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska south to California, across the northern half of North America to the Atlantic Coast.
Habitat: Shallow water, mostly in mountain lakes, sometimes completely submersed.
Origin: Native
Flowers: July-August
Spartina alterniflorasaltwater cordgrass, smooth cordgrass
Distribution: Introduced in Pacific County, Washington; common along the Atlantic and Gulf Coasts of the United States.
Habitat: Along the coast in brackish water.
Origin: Introduced from the Atlantic coast of North America
Flowers: August - September
Spartina anglicaEnglish cordgrass
Origin: Introduced from Europe
Spartina densifloraChilean cordgrass
Origin: Introduced from Chile
Spartina gracilisalkali cordgrass
Origin: Native
Flowers: June - July
Spartina patenssaltmeadow cordgrass
Origin: Introduced from the Atlantic Coast of North America
Spartina pectinatafreshwater cordgrass, prairie cordgrass
Distribution: Eastern Washington and Oregon, east to Newfoundland and North Carolina.
Habitat: Ditches, ponds, and fresh-water marshes.
Origin: Native
Flowers: June - July
Spartina ×townsendiiTownsend's cordgrass
Origin: Introduced from Europe
Spartium junceumSpanish-broom
Distribution: West of the Cascades in Washington; Washington south to California
Habitat: Disturbed areas, roadsides, forest margins.
Origin: Introduced
Flowers: April-September
Spergula arvensiscorn spurry
Distribution: Introduced in much of the United States; mostly west of the Cascades in Washington and Oregon
Habitat: Weed of waste ground, usually at lower elevations
Origin: Introduced from Europe
Flowers: March - October
Spergularia bocconeiBocconi's sandspurry
Origin: Introduced
Spergularia canadensisCanada sandspurry
Distribution: Along the coast in Washington; Alaska south to California.
Habitat: Coastal tidelands and mudflats.
Origin: Native
Flowers: June-August
var. occidentalis – Canadian sandspurry
Spergularia diandraalkali sandspurry
Origin: Introduced from Europe
Flowers: April - July
Spergularia macrothecabeach sandspurry
Distribution: Along the coast in Washington; British Columbia south to Baja California.
Habitat: Along the sea shore, often in salt marshes and rock crevices in the splash zone.
Origin: Native
Flowers: June-September
var. macrotheca – beach sandspurry
Spergularia rubrared sandspurry
Distribution: Occurring throughout Washington; introduced from Europe and common throughout North America.
Habitat: Weed of gardens, waste places, disturbed grasslands and forest openings.
Origin: Introduced from Europe
Flowers: April-October
Spergularia salinasaltmarsh sandspurry
Distribution: Both coastal and inland populations in Washington; Native and introduced throughout North America.
Habitat: Saline or brackish areas along the coast, and alkaline areas inland.
Origin: Introduced
Flowers: May-August
Sphaeralcea grossulariifoliagooseberry-leaved globemallow
Distribution: Occurring east of the Cascades crest in Washington; south-central Washington to Nevada, east to southern Idaho and Utah.
Habitat: Sagebrush desert to low elevations in the mountains.
Origin: Native
Flowers: May-July
Sphaeralcea munroanaMunro's globemallow, white-stemmed globemallow
Distribution: Widely distributed east of the Cascades crest in Washington; south-central British Columbia to California, east to Montana, Wyoming, and Colorado.
Habitat: Desert plains to open lower mountain slopes.
Origin: Native
Flowers: May-August
Sphaerophysa salsulared bladder-vetch, alkali swainsonpea
Distribution: Occurring east of the Cascades in Washington, chiefly in the central part of the state; Washington to California, east to the Great Plains.
Habitat: Alkaline soil at low elevations, often where disturbed.
Origin: Introduced
Flowers: May-July
Sphenopholis intermediaslender wedgescale
Origin: Native
Sphenopholis obtusataprairie wedgescale
Origin: Native
Flowers: June - July
Spinulum annotinuminterrupted clubmoss, stiff clubmoss
Distribution: Alaska to Oregon, east to Montana and south in the Rockies to New Mexico; across Canada and in eastern United States from Maine to Virginia
Habitat: Moist forests, bog edges and rocky areas, lowlands to subalpine
Origin: Native
Spiraea douglasiiDouglas's spiraea, hardhack steeplebush
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Montana and Colorado.
Habitat: Swamps, lake margins and damp meadows, from sea level to the subalpine.
Origin: Native
Flowers: June-August
var. douglasii – Douglas's spiraea
var. menziesii – Menzies's spiraea
Spiraea ×hitchcockiiHitchcock's spiraea
Distribution: Currently only known from Pierce County in Washington; Washington south to Oregon.
Habitat: Forest openings at low to moderate elevations in the mountains.
Origin: Native
Flowers: June-August
Spiraea lucidashiny-leaf spiraea, shinyleaf spiraea
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to Oregon, east to Saskatchewan and Wyoming.
Habitat: Stream banks and open to wooded areas, sea level to high elevations in the mountains.
Origin: Native
Flowers: June-August
Spiraea ×pyramidatapyramid spiraea
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to south Oregon, east to Idaho and Montana.
Habitat: Somewhat dry forest openings, moderate to mid-elevations in the mountains.
Origin: Native
Flowers: June-August
Spiraea splendensrosy spiraea, subalpine spiraea
Distribution: Chiefly in the Cascades and Olympic Mountains of Washington; British Columbia south to California and Nevada, east to Montana and Wyoming.
Habitat: Moist forest openings and rocky slopes, mid- to high elevations in the mountains.
Origin: Native
Flowers: June-August
Spiranthes diluvialisdiluvial ladies'-tresses
Distribution: Occurring east of the Cascades in Washington; scattered localities in Colorado, Utah, Wyoming, Idaho and Montana.
Habitat: Moist to wet meadows, marshes, and riparian areas.
Origin: Native
Flowers: July-September
Spiranthes porrifoliawestern ladies'-tresses
Distribution: Washington south to California, east to Idaho.
Habitat: Moist to swampy areas.
Origin: Native
Flowers: July-August
Spiranthes romanzoffianahooded ladies'-tresses
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska south to California, east to the Rocky Mountains and across the northern U.S. and Canada to the Atlantic Coast.
Habitat: Seasonally moist to swampy areas, sometimes in disturbed areas.
Origin: Native
Flowers: July-September
Spirodela polyrhizaduckmeal, common duckmeat, greater duckweed
Distribution: Widely distributed throughout the United States and southern Canada
Habitat: Quiet water, ponds, marshes and slow-moving streams
Origin: Native
Flowers: July - September
Sporobolus airoidesalkali-sacaton
Origin: Native
Flowers: July - August
Sporobolus composituscomposite dropseed, tall dropseed
Origin: Native
var. compositus – rough dropseed
Sporobolus cryptandrussand dropseed
Distribution: British Columbia south, east of the Cascades, to southern California, east to Ontario, Maine, and most of the United States except the extreme southeast.
Habitat: Sagebrush desert, especilly where sandy, to the foothills and grassland.
Origin: Native
Flowers: June - July
Sporobolus neglectussmall dropseed
Origin: Native
Flowers: July - September
Stachys arvensisfield hedge-nettle, staggerweed
Distribution: West of the Cascades in Washington near Seattle and Bellingham; British Columbia south to California; Gulf Coast and northeastern U.S.
Habitat: Weed in disturbed areas.
Origin: Introduced
Flowers: April-June
Stachys byzantina
Origin: Introduced
Stachys cooleyaeCooley's hedge-nettle
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California.
Habitat: Forest understory, openings, and margins from low to moderate elevations in the mountains; often where moist.
Origin: Native
Flowers: June-August
Stachys mexicanaMexican hedge-nettle
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska south to California.
Habitat: Forest understory, openings, and margins, often where moist.
Origin: Native
Flowers: June-August
Stachys pilosamarsh betony, swamp hedge-nettle
Distribution: Occurring chiefly east of the Cascades crest in Washington; widely distributed throughout most of North America except extreme southeastern U.S. and northeastern Canada.
Habitat: Swamps, marshes, wetlands and riparian areas.
Origin: Native
Flowers: June-August
var. pilosa – marsh betony, swamp hedge-nettle
Stachys rigidarigid hedge-nettle
Distribution: Scattered locations mostly west of the Cascades in Washington; south to California and adjacent Nevada.
Habitat: Stream banks and moist bottom lands, mostly at low elevations.
Origin: Native
Flowers: July-August
Stellaria alsinebog stichwort
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to Washington in western North America; native to eastern North America; also introduced in Chile.
Habitat: Streambanks, culverts, ditches, and moist forest edges, typically where disturbed.
Origin: Introduced from Europe
Flowers: May-August
Stellaria borealis
Distribution: Alaska to California, east to New York and Wyoming.
Habitat: Moist areas, rocky slopes and meadows.
Origin: Native
Flowers: Late May - early August
ssp. borealis – boreal starwort
ssp. sitchana – boreal starwort
Stellaria calycanthanorthern bog starwort
Distribution: Circumpolar, south in North America to California, Michegan and New York.
Habitat: Moist meadows and steam banks, low to high elevations.
Origin: Native
Flowers: Late May - Early August
Stellaria crispacrisped starwort
Distribution: Alaska to California, east to Alberta and Wyoming.
Habitat: Moist areas in the lowlands and lower mountains.
Origin: Native
Flowers: Late May - Early August
Stellaria gramineagrass-leaf starwort
Distribution: Introduced and abundant in eastern United States; occasional in western Washington and Idaho.
Habitat: Chiefly in lawns.
Origin: Introduced from Eurasia
Flowers: May - July
Stellaria humifusasaltmarsh starwort
Distribution: Occurring along the coast in Washington; Alaska south to Oregon, east across Canada to the Atlantic coast; circumpolar.
Habitat: Salt marshes.
Origin: Native
Flowers: June-August
Stellaria longifolialong-leaved starwort
Distribution: Occurring on both sides of the Cascades crest in Washington; widely distributed throughout North America except in the south-central and southeastern U.S.
Habitat: Wet meadows, swamps, marshes, forested wetlands at low to moderate elevations.
Origin: Native
Flowers: May-August
Stellaria longipeslongstalk starwort
Distribution: Widely distributed throughout Washington; Alaska south to California, east to New York and New Mexico.
Habitat: Moist streambanks and rocky slopes at mid-elevations in the mountains.
Origin: Native
Flowers: May-August
ssp. longipes – Goldie's starwort
Stellaria mediacommon chickweed
Distribution: Widely distributed throughout most of Washington; widely distributed throughout North America.
Habitat: Disturbed areas, often where moist in spring; very common.
Origin: Introduced from Eurasia
Flowers: February-October
Stellaria neglectagreater chickweed
Origin: Introduced
Stellaria nitensshiny starwort
Distribution: British Columbia to Baja California, east to Idaho and Utah.
Habitat: Gravelly prairies and stream banks to grassy hillsides at low elevations.
Origin: Native
Flowers: April - June
Stellaria obtusablunt-sepaled starwort
Distribution: Occurring on both sides of the Cascades in Washington; British Columbia south to California, east to the Canadian and Southern Rocky Mountains.
Habitat: Moist forest and riparian zone understory, talus slopes, from low to moderate elevations.
Origin: Native
Flowers: June-July
Stellaria pallidalesser chickweed
Origin: Introduced
Stellaria umbellataumbrella starwort
Distribution: Occurring chiefly east of the Cascades crest in central and south-central Washington; Alaska south to California, east to Northwest Territories, south throughout western U.S.
Habitat: Wetlands, riparian zones, stream banks.
Origin: Native
Flowers: July-August
Stenotus lanuginosuswoolly goldenweed
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Idaho, Montana, and Nevada.
Habitat: Open, dry, often rocky places, from sagebrush desert to ponderosa pine forest openings at middle elevations in the mountains.
Origin: Native
Flowers: May-July
var. lanuginosus – woolly goldenweed, woolly stenotus
Stephanomeria exiguasmall wirelettuce
Distribution: Occurring east of the Cascades crest in Washington, where known from Douglas County; otherwise central Oregon to California, east to Idaho, Colorado, and Texas.
Habitat: Sandy, open sites, often in sagebrush.
Origin: Native
Flowers: June-August
ssp. exigua – skeletonplant, small wirelettuce
Stephanomeria paniculatastiff-branched stephanomeria, stiff-branched wirelettuce
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
Stephanomeria tenuifoliawire lettuce, narrowleaf stephanomeria
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to California, east to the Rocky Mountains, northern Great Plains, and Texas.
Habitat: Dry, often rocky places, from the foothills and plains to moderate elevations in the mountains.
Origin: Native
Flowers: June-September
Streptanthella longirostrislong-beaked fiddle mustard, streptanthella
Distribution: Occurring in south-central Washington; Washington south to California, east to Wyoming and New Mexico.
Habitat: Open desert and sagebrush slopes.
Origin: Native
Flowers: April-May
Streptopus amplexifoliuscucumber root, clasping twisted stalk, clasp-leaf twisted-stalk, clasping twisted-stalk
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, also in northeastern North America.
Habitat: Open to dense moist forests from low elevations to subalpine.
Origin: Native
Flowers: May-July
Streptopus lanceolatusrosy twisted stalk
Distribution: Distributed throughout the Olympic and Cascade mountains in Washington; Alaska south to Oregon.
Habitat: Streambanks and damp woods at moderate to high elevations in the mountains.
Origin: Native
Flowers: June-August
Streptopus streptopoidesKruhsea, kruhsea
Origin: Native
Struthiopteris spicantdeer fern
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, also from southeastern British Columbia to southern Idaho.
Habitat: Forest understory, sometimes where moist, sea level to mid-elevations.
Origin: Native
Stuckenia filiformisslender-leaved pondweed, western pondweed, threadleaf-pondweed
Distribution: Only known from Whatcom County in Washington; Alaska south to California, east to the Rocky Mountains; east across Canada to the Atlantic Coast and Greenland.
Habitat: Lakes, ponds, slow moving waters.
Origin: Native
Flowers: June-August
Stuckenia pectinatafennel-leaved pondweed, sago pondweed, sago-pondweed
Distribution: Both sides of the Cascades in Washington; common throughout North America; Eurasia
Habitat: Shallow, fresh to brackish water.
Origin: Native
Flowers: July-September
Stuckenia vaginatabigsheath-pondweed
Origin: Native
Flowers: Late June - August
Suaeda calceoliformispaiuteweed, common seablite, horned seablite, pahute weed
Distribution: Occurring on both sides of the Cascades crest in Washington; widely distributed throughout North America from Alaska south to California, east to the Great Plains, and also along the coast of eastern North America.
Habitat: Open, moist to wet areas, typically where saline.
Origin: Native
Flowers: June-August
Suaeda nigrabushy seablite seepweed
Distribution: Occurring in Klickitat County in Washington; south-central Washington to California, east to the Great Plains.
Habitat: Alkaline soils in sagebrush flats and valleys.
Origin: Native
Flowers: June-August
Suaeda occidentalisslender seablite, western seepweed
Distribution: Eastern Washington to northern Nevada, east through southern Idaho to Colorado.
Habitat: Saline or alkaline flats and marshes in sagebrush area.
Origin: Native
Flowers: Late June - August
Subularia aquatica
Distribution: Known from a few locations in northwestern Washington; Alaska to California, east to the Rocky Mountains and across the northern U.S. and Canada to the Atlantic Coast.
Habitat: Shallow water or mud flats of ponds, lakes, slow-moving streams, tidal flats, wet meadows, and marshes.
Origin: Native
Flowers: July-September
ssp. americana – awlwort
Suksdorfia violaceaviolet mock brookfoam
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to Oregon, east to Alberta, Montana and Idaho.
Habitat: Vernally moist mossy banks and rock crevices.
Origin: Native
Flowers: March-June
Sullivantia oreganaOregon coolwort
Distribution: Columbia River Gorge and lower Willamatte Valley, Oregon.
Habitat: On moist cliffs, especially near waterfalls.
Origin: Native
Flowers: Late May - August
Swertia perennisalso felwort, alpine bog swertia
Distribution: Narrowly distributed in Cascades of Washington; Alaska south to California, east through the Rocky Mountains.
Habitat: Streambanks, wet meadows and other moist places, mid- to high elevations in the mountains.
Origin: Native
Flowers: July-August
Symphoricarpos albuscommon snowberry
Distribution: Occurring on both sides of the Cascades crest and distributed widely throughout Washington; Alaska to California, east to the Great Plains, and further east to northeastern North America.
Habitat: Thickets, forest edge, and open slopes, from the lowlands to middle elevations in the mountains.
Origin: Native
Flowers: May-August
var. albus – common snowberry
var. laevigatus – common snowberry
Symphoricarpos molliscreeping snowberry
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Nevada, disjunct in north-central Idaho.
Habitat: Slopes and forest edge, often where wet, from low to middle elevations.
Origin: Native
Flowers: May-July
var. hesperius – creeping snowberry, spreading snowberry
Symphoricarpos occidentaliswestern snowberry, wolfberry
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to Utah, east to the Atlantic Coast.
Habitat: Prairies, forest margins, and bottomlands from low to mid-elevations.
Origin: Native
Flowers: June-August
Symphoricarpos rotundifoliusmountain snowberry
Distribution: Occurring chiefly east of the Cascades in Washington; British Columbia to California east to Rocky Mountains and Great Plains.
Habitat: Open slopes and dry meadows, from sagebrush desert to middle elevations in the mountains.
Origin: Native
Flowers: May-July
var. vaccinioides – mountain snowberry
Symphyotrichum ×amethystinumamethyst aster, hybrid aster
Origin: Introduced
Symphyotrichum ascendensintermountain aster, long-leaved aster, western American aster, western aster
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to the Rocky Mountains and northern Great Plains.
Habitat: Meadows, grasslands, and forest openings, often where moist.
Origin: Native
Flowers: July-October
Symphyotrichum borealenorthern bog aster, rush aster, slender white aster
Distribution: Occurring east of the Cascades crest in northeastern Washington; Alaska to Washington, east across Canada and the northern U.S. to the Atlantic Coast.
Habitat: Cold bogs.
Origin: Native
Flowers: July-September
Symphyotrichum bracteolatumbracted aster, Eaton's aster, Oregon aster
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Sasketchewan and Rocky Mountain states.
Habitat: Moist to wet sunny places, wet thickets, along streams and ditches
Origin: Native
Flowers: July-September
Symphyotrichum campestrewestern meadow aster
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, Wyoming, and Colorado.
Habitat: Dry to moist forest openings, shorelines, and other open areas from low to middle elevations.
Origin: Native
Flowers: June-August
Symphyotrichum chilensecommon California aster, Pacific aster
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California.
Habitat: Coastal, bluffs, grasslands, open slopes, salt marsh margins, and disturbed ground.
Origin: Native
Flowers: July-October
Symphyotrichum ciliatumalkali American aster, rayless alkali aster, rayless annual aster
Distribution: Occurring east of the Cascades crest in northern Washington; British Columbia to northern Washington, east across Canada and the northern U.S. to the Atlantic Coast.
Habitat: Moist to dry open forest and meadows.
Origin: Native
Flowers: August-September
Symphyotrichum ×columbianumhybrid aster
Origin: Native
Symphyotrichum ericoidesheath-leaved aster, tufted white prairie aster
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to Oregon, east to the Rocky Mountains, and further east across Canada and most of North America to the Atlantic Coast.
Habitat: Open, wet or dry places in the valleys and plains; tolerant of alkali.
Origin: Native
Flowers: July-September
var. pansum – little gray aster, tufted white prairie aster, white heath aster
Symphyotrichum foliaceumalpine leafybract aster, Canby's leafybract aster, Cusick's American aster, Cusick's aster, Henderson's aster, Kootenai aster, leafy aster, leafy-bracted aster, Parry's aster
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Open, usually moist areas, low to high elevations in the mountains.
Origin: Native
Flowers: July-September
Symphyotrichum frondosumalkali aster, short rayed aster, short-rayed alkali aster
Distribution: British Columbia to California, esat to Idaho, Wyoming, Colorado, and New Mexico.
Habitat: Moist, usually saline soil, often along the shores of lakes and ponds, or in vernally moist, alkaline bottoms.
Origin: Native
Flowers: August-October
Symphyotrichum halliiHall's aster
Distribution: Occurring west of the Cascades crest in Washington; Washington to Oregon.
Habitat: Dry, open places in the valleys and plains.
Origin: Native
Flowers: July-October
Symphyotrichum jessicaeJessica's aster, Palouse aster
Distribution: Occurring east of the Cascades crest in eastern Washington; eastern Washington to adjacent western Idaho.
Habitat: Streambanks and open places.
Origin: Native
Flowers: July-September
Symphyotrichum laeveGeyer's aster, smooth aster
Distribution: Occurring east of the Cascades crest in eastern Washington; Yukon Territory to California, east across most of North America to the Atlantic Coast.
Habitat: Open places in the plains and valleys to middle elevations in the mountains.
Origin: Native
Flowers: July-September
var. geyeri – Geyer's smooth aster
Symphyotrichum lanceolatummarsh aster, western willow aster
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Moist meadows, sometimes where saline, shores, and open forest at low to middle elevations.
Origin: Native
Flowers: July-September
var. hesperium – lance-leaved aster, panicled aster, white panicled aster
Symphyotrichum novae-angliaeNew England aster
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; southwestern British Columbia to Oregon, east to the Rocky Mountains; native from central North America east to the Atlantic Coast.
Habitat: Roadsides and disturbed areas where somewhat moist.
Origin: Introduced from central and eastern North America
Flowers: July-September
Symphyotrichum pilosumhairy aster
Distribution: Occurring in scattered locations east of the Cascades crest in Washington; southwestern British Columbia to Washington, otherwise native from the U.S. Great Plains east to the Atlantic Coast.
Habitat: River cobbles, gravel, disturbed ground, and railroads.
Origin: Introduced from central and eastern North America
Flowers: August-October
var. pilosum – hairy aster
Symphyotrichum spathulatumwestern aster, western mountain aster
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Meadows and forest openings, from middle elevations to the subalpine.
Origin: Native
Flowers: July-September
Symphyotrichum subspicatumDouglas' aster, Douglas's aster
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana and Idaho.
Habitat: Moist woods, streambanks and seashores.
Origin: Native
Flowers: July-September
Symphytum asperumprickly comfrey, rough comfrey
Distribution: Introduced and occasionally escaped from cultivation, scattered in the United States; chiefly west of the Cascades in Washington.
Habitat: Roadsides and other disturbed habitats.
Origin: Introduced from sw Asia
Flowers: May - July
Symphytum officinalecommon comfrey
Distribution: Distributed west of the Cascades in Washington; widely distributed throughout North America except in extreme north and south states/provinces.
Habitat: Escaped from cultivation, often found in disturbed areas.
Origin: Introduced from Europe
Flowers: May-August
Symphytum ×uplandicumhybrid comfrey
Origin: Introduced from Europe
Syringa vulgariscommon lilac
Origin: Introduced