Vascular Plants

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

Browse by common name:
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z
Common names beginning with T:
Lion's tail (Leonurus cardiaca)
Distribution: Scattered location in Washington; found occasionally in North America.
Habitat: Disturbed ground, often in association with cities and towns.
Origin: Introduced from Eurasia
Flowers: June-September
Small-flower tamarisk (Tamarix parviflora)
Distribution: Chiefly east of the Cascades in Washington; distributed widely througout western and central U.S., scattered localities in eastern U.S.
Habitat: Mostly in riparian areas in arid regions.
Origin: Introduced from Europe
Flowers: May-June
Camphor tansy (Tanacetum bipinnatum)
Distribution: British Columbia to northern California.
Habitat: Sand dunes along the coast.
Origin: Native
Flowers: June - September
Common tansy (Tanacetum vulgare)
Distribution: Widely distributed throughout Washington; widely distributed throughout North America.
Habitat: Roadsides and waste ground, often cultivated and escaped
Origin: Introduced from Europe
Flowers: July-October
Dune tansy (Tanacetum bipinnatum)
Distribution: British Columbia to northern California.
Habitat: Sand dunes along the coast.
Origin: Native
Flowers: June - September
Mountain tansymustard (Descurainia incana)
Origin: Native
Mountain tansymustard (Descurainia longepedicellata)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to Oregon and Nevada, east to the Rocky Mountains from Montana to Arizona, but not New Mexico.
Habitat: Moderately dry forest openings and sagebrush steppe.
Origin: Native
Flowers: April-June
Narrow tansymustard (Descurainia longepedicellata)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to Oregon and Nevada, east to the Rocky Mountains from Montana to Arizona, but not New Mexico.
Habitat: Moderately dry forest openings and sagebrush steppe.
Origin: Native
Flowers: April-June
Nelson's tansymustard (Descurainia nelsonii)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Montana, Wyoming, Idaho, and Nevada.
Habitat: Sagrebrush-steppe to open montane forests.
Origin: Native
Flowers: May-June
Sagebrush tansymustard (Descurainia nelsonii)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Montana, Wyoming, Idaho, and Nevada.
Habitat: Sagrebrush-steppe to open montane forests.
Origin: Native
Flowers: May-June
Sticky tansymustard (Descurainia longepedicellata)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to Oregon and Nevada, east to the Rocky Mountains from Montana to Arizona, but not New Mexico.
Habitat: Moderately dry forest openings and sagebrush steppe.
Origin: Native
Flowers: April-June
Western tansymustard (Descurainia pinnata)
Distribution: Occurring on both sides of the Cascades crest in Washington, but chiefly to the east; widely distributed throughout most of North America.
Habitat: Weedy native of fairly dry, open ground.
Origin: Native
Flowers: April-July
Tapegrass (Vallisneria americana)
Distribution: Native from Quebec to Texas and Florida; introduced in Dry Falls Coulee, Grant County, and several lakes west of the Cascades in Washington; also in Oregon and Idaho
Habitat: Ponds, lakes and quiet streams
Origin: Introduced from eastern North America
Flowers: July - September
Noxious tararisk (Tamarix ramosissima)
Distribution: Chiefly east of the Cascades in Washington; widespread across the central and western U.S., scattered location in U.S. east of the Mississippi River.
Habitat: Riparian zones and other moist to wet areas in arid regions.
Origin: Introduced from Europe
Flowers: June-August
Smooth tare (Vicia tetrasperma)
Distribution: Occurring west of the Cascades crest in Washington; southwestern British Columbia to California, also in northern Idaho and western Montana.
Habitat: Roadsides, fields, forest edge, wastelots, and other disturbed areas.
Origin: Introduced from Europe
Flowers: May-August
Tare (Lolium temulentum)
Origin: Introduced
Flowers: May - June
Tare (Vicia sativa)
Distribution: Occurring on both sides of the Cascades crest and east in the Columbia River Gorge in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Roadsides, fields, forest edges, thickets, lawns, wastelots, and other disturbed open areas.
Origin: Introduced from Eurasia
Flowers: April-July
Chilean tarplant (Madia sativa)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California.
Habitat: Dry, open places at low elevations, often along roadsides or other disturbed sites.
Origin: Native
Flowers: June-September
Grassy tarplant (Madia gracilis)
Distribution: Widely distributed throughout Washington; British Columbia south to California, east to Montana, Idaho, Nevada, and Utah.
Habitat: Dry, open areas from shrub-steppe to mid-elevations in the mountains.
Origin: Native
Flowers: June-August
Lemon scented tarplant (Madia citriodora)
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Nevada.
Habitat: Dry, open hillsides and foothills.
Origin: Native
Flowers: May-June
Little tarplant (Madia exigua)
Distribution: Occurring on both sides of the Cascades crest in Washington, but more common east of the crest; British Columbia to California, east to Montana, Idaho, and Nevada.
Habitat: Dry, open woods, grasslands, roadsides, and other open areas where often disturbed, from the plains and foothills, occasionally up to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Mountain tarplant (Madia glomerata)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to south to California, east to the Rocky Mountains and across northern U.S. and southern Canada to the Atlantic Coast.
Habitat: Common in dry, open places from the foothills to mid-elevations in the mountains.
Origin: Native
Flowers: July-September
Smallhead tarplant (Hemizonella minima)
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east to Montana and Nevada.
Habitat: Dry, open areas in sagebrush, grasslands, and ponderosa pine forest openings.
Origin: Native
Flowers: May-July
Woodland tarplant (Anisocarpus madioides)
Distribution: Occurring west of the Cascades crest in lowland western Washington; Southern British Columbia to southern California.
Habitat: Open woods and woodland edge, and thickets.
Origin: Native
Flowers: May-July
Tarragon (Artemisia dracunculus)
Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to the Great Plains and Great Lakes region.
Habitat: Sagebrush desert to ponderosa pine forest openings at middle elevations.
Origin: Native
Flowers: July-October
Autumn showy tarweed (Madia elegans)
Distribution: Southwest Washington, south through western Oregon to California.
Habitat: Dry, open places, often becoming a roadside weed.
Origin: Native
Flowers: July - September
Cluster tarweed (Madia glomerata)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to south to California, east to the Rocky Mountains and across northern U.S. and southern Canada to the Atlantic Coast.
Habitat: Common in dry, open places from the foothills to mid-elevations in the mountains.
Origin: Native
Flowers: July-September
Coast tarweed (Madia sativa)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California.
Habitat: Dry, open places at low elevations, often along roadsides or other disturbed sites.
Origin: Native
Flowers: June-September
Common tarweed (Madia gracilis)
Distribution: Widely distributed throughout Washington; British Columbia south to California, east to Montana, Idaho, Nevada, and Utah.
Habitat: Dry, open areas from shrub-steppe to mid-elevations in the mountains.
Origin: Native
Flowers: June-August
Least tarweed (Hemizonella minima)
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east to Montana and Nevada.
Habitat: Dry, open areas in sagebrush, grasslands, and ponderosa pine forest openings.
Origin: Native
Flowers: May-July
Lemon scented tarweed (Madia citriodora)
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Nevada.
Habitat: Dry, open hillsides and foothills.
Origin: Native
Flowers: May-June
Lemon tarweed (Madia citriodora)
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Nevada.
Habitat: Dry, open hillsides and foothills.
Origin: Native
Flowers: May-June
Little tarweed (Madia exigua)
Distribution: Occurring on both sides of the Cascades crest in Washington, but more common east of the crest; British Columbia to California, east to Montana, Idaho, and Nevada.
Habitat: Dry, open woods, grasslands, roadsides, and other open areas where often disturbed, from the plains and foothills, occasionally up to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Mountain tarweed (Madia glomerata)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to south to California, east to the Rocky Mountains and across northern U.S. and southern Canada to the Atlantic Coast.
Habitat: Common in dry, open places from the foothills to mid-elevations in the mountains.
Origin: Native
Flowers: July-September
Slender tarweed (Madia gracilis)
Distribution: Widely distributed throughout Washington; British Columbia south to California, east to Montana, Idaho, Nevada, and Utah.
Habitat: Dry, open areas from shrub-steppe to mid-elevations in the mountains.
Origin: Native
Flowers: June-August
Small-head tarweed (Hemizonella minima)
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east to Montana and Nevada.
Habitat: Dry, open areas in sagebrush, grasslands, and ponderosa pine forest openings.
Origin: Native
Flowers: May-July
Smallhead tarweed (Hemizonella minima)
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east to Montana and Nevada.
Habitat: Dry, open areas in sagebrush, grasslands, and ponderosa pine forest openings.
Origin: Native
Flowers: May-July
Woodland tarweed (Anisocarpus madioides)
Distribution: Occurring west of the Cascades crest in lowland western Washington; Southern British Columbia to southern California.
Habitat: Open woods and woodland edge, and thickets.
Origin: Native
Flowers: May-July
Large flowered tasselflower (Brickellia grandiflora)
Distribution: Occasional east of the Cascades in Washington and Oregon.
Habitat: Openings in woods at moderate elevations, sometimes in plains.
Origin: Native
Flowers: July-October
Strickland's tauschia (Tauschia stricklandii)
Distribution: Occurring in the Cascades in Washington, where endemic to Mount Rainier National Park and nearby Yakima County.
Habitat: Moist meadows, forest openings and edge at middle elevations.
Origin: Native
Flowers: July-August
California tea (Rupertia physodes)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California, disjunct in northeastern Oregon and adjacent Idaho.
Habitat: Prairie and forest edges at low elevations.
Origin: Native
Flowers: May-June
Mexican tea (Dysphania ambrosioides)
Distribution: Occurring in scattered locations in Washington; native to southeastern U.S., but introduced in scattered localities in central and western U.S.
Habitat: Roadsides and waste areas, riparian zones, tolerant of alkaline.
Origin: Introduced from southern North America and tropical America
Flowers: July-November
Mt. Labrador tea (Rhododendron columbianum)
Distribution: Occurring on both sides of the Cascades in Washington; British Columbia and Alberta south to California, east to Montana, Wyoming, and Utah.
Habitat: Swamps and bogs, lowlands to mid-elevations in the mountains.
Origin: Native
Flowers: June-August
Oswego tea (Monarda didyma)
Origin: Introduced from eastern North America
Smooth Labrador tea (Rhododendron columbianum)
Distribution: Occurring on both sides of the Cascades in Washington; British Columbia and Alberta south to California, east to Montana, Wyoming, and Utah.
Habitat: Swamps and bogs, lowlands to mid-elevations in the mountains.
Origin: Native
Flowers: June-August
Western Labrador tea (Rhododendron columbianum)
Distribution: Occurring on both sides of the Cascades in Washington; British Columbia and Alberta south to California, east to Montana, Wyoming, and Utah.
Habitat: Swamps and bogs, lowlands to mid-elevations in the mountains.
Origin: Native
Flowers: June-August
Western teaberry (Gaultheria ovatifolia)
Distribution: Chiefly in the Olympics and Cascades mountains in Washington, but also in the northeastern part of the State; British Columbia south to California, east to Idaho and Montana.
Habitat: Forested areas from fairly dry Ponderosa pine to subalpine bogs.
Origin: Native
Flowers: June-August
Teasel (Dipsacus fullonum)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across most of North America.
Habitat: Disturbed, open areas often where at least seasonally wet; low to moderate elevations.
Origin: Introduced
Flowers: June-December
Oregon teatree (Ceanothus sanguineus)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east to western Montana.
Habitat: Moist to dry open forest, slopes, and thickets, from low to middle elevations.
Origin: Native
Flowers: May-July
Rosette tequilia (Tiquilia nuttallii)
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to Utah.
Habitat: Sagebrush plains.
Origin: Native
Flowers: May-August
Thalecress (Arabidopsis thaliana)
Distribution: Widely distributed througout Washington; widely distributed throughout North America.
Habitat: Disturbed areas, particularly near cities and towns.
Origin: Introduced from Eurasia
Flowers: March-May
Cut-leaf thelypody (Thelypodium laciniatum)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Idaho and Nevada.
Habitat: Rock cliffs and dry, rocky areas.
Origin: Native
Flowers: April-July
Entire-leaved thelypody (Thelypodium integrifolium)
Distribution: Occurring east of the Cascades crest in Washington; Washington to central Oregon and Nevada, east to Montana and Colorado.
Habitat: Sagebrush plains to streambanks in the lower mountains.
Origin: Native
Flowers: June-August
Howell's thelypody (Thelypodium howellii)
Origin: Native
Flowers: May - July
Many flowered thelypody (Thelypodium milleflorum)
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to Nevada, east to Idaho.
Habitat: Rock cliffs and dry, rocky areas in sagebrush desert.
Origin: Native
Flowers: April-July
Slender thelypody (Thelypodium sagittatum)
Origin: Native
Flowers: June - July
Thick-leaved thelypody (Thelypodium laciniatum)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Idaho and Nevada.
Habitat: Rock cliffs and dry, rocky areas.
Origin: Native
Flowers: April-July
Mountain thermopsis (Thermopsis montana)
Distribution: Occurring on both sides of the Cascades crest in Washington, but only occurring in the far western and eastern counties; British Columbia to California, east to the Rocky Mountains.
Habitat: Sandy, well-drained soil to wet meadowland, low to moderate elevations.
Origin: Native
Flowers: May-July
Thimbleberry (Rubus parviflorus)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to Alberta, the Rocky Mountains, and Great Lakes region.
Habitat: Forest openings and edge, thickets, meadows, and riparian corridors from sea level to the subalpine.
Origin: Native
Flowers: April-July
Blessed thistle (Centaurea benedicta)
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to the Rocky Mountains, also in eastern North America.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed, open areas.
Origin: Introduced from Eurasia
Flowers: June-August
Bull thistle (Cirsium vulgare)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east to the Atlantic Coast.
Habitat: Roadsides, fields, forest edge, ditches, balds, prairies, wastelots, and other disturbed, open areas.
Origin: Introduced from Eurasia
Flowers: June-September
Canadian thistle (Cirsium arvense)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, meadows, pastures, prairies, grasslands, wastelots, and other disturbed areas at low to middle elevations.
Origin: Introduced from Eurasia
Flowers: May-October
Clustered thistle (Cirsium brevistylum)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to northern California, east to Montana.
Habitat: Slopes, open forest, and moist meadows from low to middle elevations in the mountains.
Origin: Native
Flowers: June-August
Common thistle (Cirsium vulgare)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east to the Atlantic Coast.
Habitat: Roadsides, fields, forest edge, ditches, balds, prairies, wastelots, and other disturbed, open areas.
Origin: Introduced from Eurasia
Flowers: June-September
Cotton thistle (Onopordum acanthium)
Distribution: Chiefly east of the Cascades in Washington, but also on the west side; introduced throughout nearly all of North America.
Habitat: Noxious weed of dry, open areas and stream banks.
Origin: Introduced from Eurasia
Flowers: June-August
Creepiing thistle (Cirsium arvense)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: Roadsides, fields, meadows, pastures, prairies, grasslands, wastelots, and other disturbed areas at low to middle elevations.
Origin: Introduced from Eurasia
Flowers: May-October
Edible thistle (Cirsium edule)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Oregon.
Habitat: Forest openings and edge, meadows, roadsides, and other open areas at low to middle elevations in the mountains.
Origin: Native
Flowers: July-September
Elk thistle (Cirsium scariosum)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Wet meadows, moist, sometimes alkaline ground, and forest openings from the foothills to fairly high elevations in the mountains.
Origin: Native
Flowers: June-August
Few-leaf thistle (Cirsium remotifolium)
Distribution: Occurring west of the Cascades crest and east in the Columbia River Gorge in Washington; Washington to California.
Habitat: Meadows, stream banks, open for, brushy slopes, from low to middle elevations in the mountains.
Origin: Native
Flowers: June-September
Flodman's thistle (Cirsium flodmanii)
Distribution: British Columbia to north-central Washington,south in the Rocky Mountains from Alberta, east to the Great Plains and Great Lakes region.
Habitat: Grasslands, stream banks, and roadsides at low to middle elevations.
Flowers: June-August
Greene's thistle (Cirsium inamoenum)
Distribution: Occurring east of the Cascades crest in southeastern Washington; southeastern Washington to California, east to Idaho, Wyoming, and Utah.
Habitat: Grassland, sagebrush desert, and dry rocky slopes from low to middle elevations.
Origin: Native
Flowers: June-August
Hooker's thistle (Cirsium hookerianum)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Washington, east to Alberta, Montana, and Wyoming.
Habitat: Moist lowlands, open slopes and fields.
Origin: Native
Flowers: July-August
Meadow thistle (Cirsium scariosum)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Wet meadows, moist, sometimes alkaline ground, and forest openings from the foothills to fairly high elevations in the mountains.
Origin: Native
Flowers: June-August
Milk thistle (Silybum marianum)
Distribution: Introduced weed now well established in California; occasional at scattered locations in the Pacific Northwest.
Habitat: Waste places.
Origin: Introduced from the Mediterranean region
Flowers: May - July
Musk thistle (Carduus nutans)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed, open areas.
Origin: Introduced from Eurasia
Flowers: June-October
Nodding thistle (Carduus nutans)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed, open areas.
Origin: Introduced from Eurasia
Flowers: June-October
Pacific fringed thistle (Cirsium remotifolium)
Distribution: Occurring west of the Cascades crest and east in the Columbia River Gorge in Washington; Washington to California.
Habitat: Meadows, stream banks, open for, brushy slopes, from low to middle elevations in the mountains.
Origin: Native
Flowers: June-September
Palouse thistle (Cirsium brevifolium)
Distribution: Occurring east of the Cascades crest in eastern and southeastern Washington; eastern Washington to northeast Oregon and adjacent Idaho.
Habitat: Palouse grassland remnants, dry rocky slopes, and roadsides.
Origin: Native
Flowers: June-October
Plumeless thistle (Carduus acanthoides)
Distribution: Occurring east of the Cascades crest in northeastern Washington; British Columbia to Washington, also in California, east to the northern Rocky Mountains, Great Plains, and eastern North America.
Habitat: Roadsides, fields, ditches, and other disturbed, open areas.
Origin: Introduced from Europe
Flowers: July-October
Remote-leaved thistle (Cirsium remotifolium)
Distribution: Occurring west of the Cascades crest and east in the Columbia River Gorge in Washington; Washington to California.
Habitat: Meadows, stream banks, open for, brushy slopes, from low to middle elevations in the mountains.
Origin: Native
Flowers: June-September
Russian thistle (Salsola tragus)
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
Scotch thistle (Onopordum acanthium)
Distribution: Chiefly east of the Cascades in Washington, but also on the west side; introduced throughout nearly all of North America.
Habitat: Noxious weed of dry, open areas and stream banks.
Origin: Introduced from Eurasia
Flowers: June-August
Scots thistle (Onopordum acanthium)
Distribution: Chiefly east of the Cascades in Washington, but also on the west side; introduced throughout nearly all of North America.
Habitat: Noxious weed of dry, open areas and stream banks.
Origin: Introduced from Eurasia
Flowers: June-August
Short-styled thistle (Cirsium brevistylum)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to northern California, east to Montana.
Habitat: Slopes, open forest, and moist meadows from low to middle elevations in the mountains.
Origin: Native
Flowers: June-August
Slender flowered thistle (Carduus tenuiflorus)
Distribution: Occurring west of the Cascades crest in southwestern Washington; Washington to California, also in the eastern U.S.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed areas at low elevations.
Origin: Introduced from Europe
Flowers: June-July
Spiny plumeless thistle (Carduus acanthoides)
Distribution: Occurring east of the Cascades crest in northeastern Washington; British Columbia to Washington, also in California, east to the northern Rocky Mountains, Great Plains, and eastern North America.
Habitat: Roadsides, fields, ditches, and other disturbed, open areas.
Origin: Introduced from Europe
Flowers: July-October
Wavy leaf thistle (Cirsium undulatum)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Michigan and Texas.
Habitat: Dry hillsides and plains at low elevations.
Origin: Native
Flowers: May-September
Weak thistle (Cirsium remotifolium)
Distribution: Occurring west of the Cascades crest and east in the Columbia River Gorge in Washington; Washington to California.
Habitat: Meadows, stream banks, open for, brushy slopes, from low to middle elevations in the mountains.
Origin: Native
Flowers: June-September
White thistle (Cirsium hookerianum)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Washington, east to Alberta, Montana, and Wyoming.
Habitat: Moist lowlands, open slopes and fields.
Origin: Native
Flowers: July-August
Winged plumeless thistle (Carduus tenuiflorus)
Distribution: Occurring west of the Cascades crest in southwestern Washington; Washington to California, also in the eastern U.S.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed areas at low elevations.
Origin: Introduced from Europe
Flowers: June-July
Thompsongrass (Paspalum distichum)
Distribution: Occurring chiefly along the lower Columbia River corridor in Washington; occurring in most of western North America and the southeastern U.S.
Habitat: Along ditches and streams where the soil is moist much of the season.
Origin: Native
Flowers: August-October
Washington thorn (Crataegus phaenopyrum)
Origin: Introduced
Large flowered thoroughwort (Brickellia grandiflora)
Distribution: Occasional east of the Cascades in Washington and Oregon.
Habitat: Openings in woods at moderate elevations, sometimes in plains.
Origin: Native
Flowers: July-October
Narrow-leaved thoroughwort (Brickellia oblongifolia)
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to California east to the Rocky Mountains.
Habitat: Dry, often rocky places from lowland sagebrush desert to middle elevations in the mountains.
Origin: Native
Flowers: May-August
Threadleaf-pondweed (Stuckenia filiformis)
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
Jersey thrift (Armeria arenaria)
Distribution: Occurring west of the Cascades crest in Washington; not known from elsewhere in North America.
Habitat: Roadsides, fields, ditches, and other disturbed open areas at low elevations.
Origin: Introduced from Europe
Flowers: April-July
Thrift (Armeria maritima)
Distribution: Occurring west of the Cascades crest in Washington, chiefly in the coastal counties; Alaska to California, east across Canada to northeastern North America; Greenland and Europe.
Habitat: Along beaches, coastal bluffs and balds, occasionally inland in prairies.
Origin: Native
Flowers: March-July
Water thyme (Hydrilla verticillata)
Origin: Introduced from Eurasia
White false tickhead (Eatonella nivea)
Distribution: Occurring east of the Cascades crest in central Washington; Washington to California, east to Idaho and Nevada.
Habitat: Dry, sandy, or volcanic desert areas.
Origin: Native
Flowers: May-July
Bigleaf tickseed (Coreopsis grandiflora)
Origin: Introduced
Lance-leaved tickseed (Coreopsis lanceolata)
Origin: Introduced
Bristly-fruited tickweed (Lappula squarrosa)
Distribution: Occurring east of the Cascades crest in Washington; widely distributed throughout much of North America; Eurasia.
Habitat: Shrub-steppe, disturbed areas, roadside.
Origin: Introduced from Eurasia, possibly native in northern Rocky Mts. (Cronquist et al. 1984)
Flowers: June-August
White daisy tidytips (Layia glandulosa)
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to Idaho, Utah, Arizona and New Mexico.
Habitat: Dry, open areas from sagebrush desert to low elevations in the mountains.
Origin: Native
Flowers: April-June
Mountain Timothy (Phleum alpinum)
Distribution: Alaska east to Newfoundland, south in the subalpine regions of the mountains in most of western United States.
Habitat: Streambanks and meadows at higher elevations.
Origin: Native
Flowers: Late June - August
Timothy (Phleum pratense)
Distribution: Both sides of the Cascades in Washington; throughout North America.
Habitat: Disturbed areas, especially moist, open meadows, from coast to midmontane.
Origin: Introduced
Flowers: May-July
Blue toadflax (Nuttallanthus texanus)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to California, east to Sasketchewan and across much of the U.S. except the upper Midwest and Northeast.
Habitat: Prairies, grasslands, and balds.
Origin: Native
Flowers: May-June
Broomleaf toadflax (Linaria genistifolia)
Origin: Introduced
Canada toadflax (Nuttallanthus canadensis)
Distribution: Occurring west of the Cascades crest in Washington. Occurring in scattered locations in Washington; widely distributed in eastern half of North America.
Habitat: Disturbed areas including roadsides, wastelots, and fields.
Origin: Native?
Flowers: May-June
Dalmation toadflax (Linaria dalmatica)
Distribution: Widely distributed throughout Washington, but more prevalent east of the Cascades crest; widely distributed throughout most of North America except southeastern region.
Habitat: Open areas roadsides, fields, wastelots, forest openings, typically where disturbed.
Origin: Introduced
Flowers: May-August
False toadflax (Geocaulon lividum)
Distribution: Occurring from Okanogan County east to Pend Oreille County in Washington; Alaska south to Washington, east to Alberta, northern Idaho, and northwestern Montana.
Habitat: Bogs and open woods to lower alpine slopes.
Origin: Native
Flowers: June-July
Ivy-leaved toadflax (Cymbalaria muralis)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California, scattered eastward across North America to the Atlantic Coast where more broadly distributed.
Habitat: Roadsides, retaining walls, wastelots, and other disturbed open areas at low elevation.
Origin: Introduced from Eurasia
Flowers: April-October
Old field toadflax (Nuttallanthus canadensis)
Distribution: Occurring west of the Cascades crest in Washington. Occurring in scattered locations in Washington; widely distributed in eastern half of North America.
Habitat: Disturbed areas including roadsides, wastelots, and fields.
Origin: Native?
Flowers: May-June
Purple toadflax (Linaria purpurea)
Distribution: Introduced as an ornamental, occasionally escaping west of the Cascades in Washington.
Habitat: Bare and disturbed ground.
Origin: Introduced from Mediterranean
Flowers: June - August
Texas toadflax (Nuttallanthus texanus)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to California, east to Sasketchewan and across much of the U.S. except the upper Midwest and Northeast.
Habitat: Prairies, grasslands, and balds.
Origin: Native
Flowers: May-June
Coyote tobacco (Nicotiana attenuata)
Distribution: Wholly east of the Cascades, southern British Columbia south to California, east to Idaho and Texas.
Habitat: Dry, open plance, especially dry, sandy bottom lands.
Origin: Native
Flowers: June - September
Jersey rabbit tobacco (Pseudognaphalium luteoalbum)
Distribution: Locally introduced, chiefly west of the Cascades.
Habitat: Disturbed waste ground.
Origin: Introduced
Flowers: June - October
Ladies tobacco (Pseudognaphalium californicum)
Origin: Native
Flowers: June - July
Ladies' tobacco (Pseudognaphalium californicum)
Origin: Native
Flowers: June - July
Macoun's rabbit tobacco (Pseudognaphalium macounii)
Origin: Native
Tobacco-brush (Ceanothus velutinus)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, South Dakota, Wyoming, and Colorado.
Habitat: Moist to dry open forests, low to mid-elevations in the mountains.
Origin: Native
Flowers: June-September
Tobacco-root (Valeriana edulis)
Distribution: Occurring in the eastern region of Washington; Southern British Columbia south into Washington, Idaho, and Montana, east to Ontario and Ohio.
Habitat: A wide variety of open, somewhat moist habitats, from the foothills to rather high elevations in the mountains.
Origin: Native
Flowers: June-August
Tocalote (Centaurea melitensis)
Distribution: Occurring chiefly west of the Cascades in Washington; British Columbia to California and Mexico, east to Texas and eastern North America.
Habitat: Roadsides, meadows, balds, fields, ditches, wastelots, and other disturbed, open areas at low to middle elevations.
Origin: Introduced from the Mediterranean region
Flowers: June-September
Western tofieldia (Triantha occidentalis)
Distribution: Occurring in the Olympic and Cascade mountains in Washington; British Columbia south to California.
Habitat: Moist meadows, bogs and streambanks, mid- to high elevations in the mountains.
Origin: Native
Flowers: June-August
Tomatillo (Physalis philadelphica)
Distribution: In scattered localities in lowland western Washington; occurring across much of North America.
Habitat: Disturbed areas at low elevations near towns and cities.
Origin: Introduced from Mexico
Flowers: June-September
Wild tomatillo (Physalis longifolia)
Distribution: Occurring chiefly east of the Cascades in Washington; occurring throughout much of North America.
Habitat: Weed of cultivated fields and waste places.
Origin: Introduced
Flowers: June-September
Tomato (Solanum lycopersicum)
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
Large-flowered tonella (Tonella floribunda)
Distribution: Occurring along the southern border of Washington; Canyon of the Snake River and tributaries; Washington south to Oregon, east to Idaho.
Habitat: Open, often rocky places, at low elevations.
Origin: Native
Flowers: April-June
Small-flowered tonella (Tonella tenella)
Distribution: Along the Columbia River from the east end of the gorge to the coast, south in the Puget Trough to central California.
Habitat: Fairly moist in open to partly shaded places at low elevations.
Origin: Native
Flowers: March-May
Grand hound (Adelinia grandis)
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; Washington to California.
Habitat: Forest openings and meadows at low to moderate elevations.
Origin: Native
Flowers: April-May
Lowland toothcup (Rotala ramosior)
Origin: Native
Flowers: June - August
Nuttall's toothwort (Cardamine nuttallii)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California.
Habitat: Seasonally moist soils of forest openings to forest understory, from low to moderate elevations.
Origin: Native
Flowers: March-May
Slender toothwort (Cardamine nuttallii)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California.
Habitat: Seasonally moist soils of forest openings to forest understory, from low to moderate elevations.
Origin: Native
Flowers: March-May
Toringo (Malus toringo)
Origin: Introduced
Or western touch-me-not (Impatiens noli-tangere)
Distribution: Alaska to Oregon, from the coast inland to Idaho.
Habitat: Moist woods.
Origin: Native
Flowers: July - September
Small-flowered touch-me-not (Impatiens parviflora)
Distribution: Currently (2016) known in Washington from King County (only); southwestern British Columbia, western Washington and northwestern Oregon; also occurring in eastern North America.
Habitat: Disturbed forest edge and understory at low elevations, often where at least seasonally moist.
Origin: Introduced
Flowers: June-July
Showy Townsend-daisy (Townsendia florifer)
Distribution: Occurring east of the Cascades crest in Washington; Washington south to Oregon and Nevada, east to the Rocky Mountains.
Habitat: Dry-open places in the plains and foothills, often with sagebrush.
Origin: Native
Flowers: May-July
Showy townsendia (Townsendia florifer)
Distribution: Occurring east of the Cascades crest in Washington; Washington south to Oregon and Nevada, east to the Rocky Mountains.
Habitat: Dry-open places in the plains and foothills, often with sagebrush.
Origin: Native
Flowers: May-July
Trailplant (Adenocaulon bicolor)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east the northern Rocky Mountains, northern Great Plains, and Great Lakes region.
Habitat: Moist, shady woods at low to middle elevations.
Origin: Native
Flowers: June-September
Venus fly trap (Dionaea muscipula)
Distribution: Sparingly introduced in localities in western Washington.
Habitat: Bogs, lake margins, swamps.
Origin: Introduced from southeast United States
Flowers: July-August
Traveler's-joy (Clematis vitalba)
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Oregon, also in scattered locations in eastern North America.
Habitat: Forest edge, hillsides, parks, wastelots, and other disturbed sites.
Origin: Introduced; native to Europe and Africa
Flowers: June-September
European spindle tree (Euonymus europaeus)
Distribution: Occurring in urban areas in a few cities in Washington; widely distributed east of the Mississippi in the U.S. and in eastern Canada.
Habitat: Disturbed areas, often where moist.
Origin: Introduced
Flowers: June-July
Tree-of-heaven (Ailanthus altissima)
Distribution: Occurring mostly east of the Cascades in Washington, but also in scattered localities west of the Cascades; widely distributed throughout North America.
Habitat: Escaped ornamental in roadsides, waste areas, along railroad tracks, and other open, disturbed areas.
Origin: Introduced from China
Flowers: May-July
Big trefoil (Lotus uliginosus)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California, east to Idaho; east across Canada to Nova Scotia; scattered localities in eastern U.S.
Habitat: Moist to wet disturbed areas, roadsides, abandoned lots, and coastal tidelands.
Origin: Introduced from Europe
Flowers: May-July
Narrowleaf trefoil (Lotus tenuis)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east to the Great Plains, also in eastern North America.
Habitat: Fields, roadsides, wastelots, and other disturbed areas
Origin: Introduced from Eurasia
Flowers: May-July
Slender trefoil (Lotus tenuis)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; British Columbia to California, east to the Great Plains, also in eastern North America.
Habitat: Fields, roadsides, wastelots, and other disturbed areas
Origin: Introduced from Eurasia
Flowers: May-July
Subterranean trefoil (Trifolium subterraneum)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California; also in the southeastern U.S.
Habitat: Pastures, prairies, roadsides, lawns, fields, and other open disturbed areas at low elevations.
Origin: Introduced from Europe
Flowers: April-June
Giant trillium (Trillium albidum)
Distribution: Occurring west of the Cascades crest in Washington; Washington to California.
Habitat: Moist forests, oak-ash woodlands, thickets, and fields at low elevations.
Origin: Native
Flowers: April-June
Purple trillium (Trillium petiolatum)
Distribution: Occurring east of the Cascades crest in Washington; Washington to northeastern Oregon, east to Idaho.
Habitat: Stream banks, moist meadows, forest edge, and thickets at low to middle elevations in the mountains.
Origin: Native
Flowers: April-June
Sessile trillium (Trillium albidum)
Distribution: Occurring west of the Cascades crest in Washington; Washington to California.
Habitat: Moist forests, oak-ash woodlands, thickets, and fields at low elevations.
Origin: Native
Flowers: April-June
Trillium (Trillium ovatum)
Distribution: Widely distributed on both sides of the Cascades crest in forested areas in Washington; British Columbia to California, east to Montana, Wyoming, and Colorado.
Habitat: Open to dense moist forests at low to mid-elevations, often where boggy in the spring.
Origin: Native
Flowers: March-June
White trillium (Trillium ovatum)
Distribution: Widely distributed on both sides of the Cascades crest in forested areas in Washington; British Columbia to California, east to Montana, Wyoming, and Colorado.
Habitat: Open to dense moist forests at low to mid-elevations, often where boggy in the spring.
Origin: Native
Flowers: March-June
Nodding Trisetum (Trisetum cernuum)
Origin: Native
Spike trisetum (Trisetum spicatum)
Distribution: Occurring in the mountainous areas on both sides of the Cascades crest throughout Washington; Alaska to California, east to the Rocky Mountains, northern Great Plains, further east to the Great Lakes region and eastern North America.
Habitat: Montane forests to alpine slopes in rocky, dry or moist areas.
Origin: Native
Flowers: June-September
Large-flowered tritelia (Triteleia grandiflora)
Distribution: Occurring chiefly east of the Cascades crest in Washington, but also occurring in the north Puget Sound area; British Columbia to California, east to Montana, Idaho, Wyoming and Utah.
Habitat: Prairies, grasslands, balds and forest openings, often where seasonally dry, from the coast to middle elevations in the mountains.
Origin: Native
Flowers: April-June
Quinault trout-lily (Erythronium quinaultense)
Distribution: Occurring west of the Cascades crest on the Olympic Peninsula in Washington, where endemic to Grays Harbor and Jefferson counties.
Habitat: Coniferous forest understory and edge, and moist slopes at low to moderate elevations.
Origin: Native
Flowers: May-June
Yellow trumpet (Sarracenia flava)
Distribution: Native in southeastern United States; introduced in western Washington.
Habitat: Swamps, bogs and seeps.
Origin: Introduced from southeast United States
Flowers: May - June
Tuckahoe (Peltandra virginica)
Distribution: Occurring in scattered locations west of the Cascades crest in Washington; western Washington to northwestern Oregon, otherwise eastern North America where native.
Habitat: Shallow water of slow moving water, ponds, and lake shores at low elevation.
Origin: Introduced from eastern North America
Flowers: June-August
Common tule (Schoenoplectus acutus)
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
Common garden tulip (Tulipa gesneriana)
Origin: Introduced from Old World, exact origin unknown
Loesel's tumblemustard (Sisymbrium loeselii)
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
Tumbleweed (Amaranthus albus)
Distribution: Occurring east of the Cascades crest in Washington; widely distributed throughout much of North America.
Habitat: Dry, disturbed areas.
Origin: Introduced from tropical America
Flowers: June-September
Tumbleweed (Salsola tragus)
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
Turkey peas (Lomatium linearifolium)
Distribution: Occurring east of the Cascades crest in Washington; central Washington to north-central Oregon, east to Montana and Wyoming.
Habitat: Open slopes and ridges, from low to middle elevations.
Origin: Native
Flowers: March-May
Western turkeybeard (Xerophyllum tenax)
Distribution: Occurring in the mountainous areas of Washington except in the southeastern region of the State; British Columbia south to California, east to the northern Rocky Mountains.
Habitat: Open woods and clearings, from near sea level on the Olympic Peninsula to high elevations in the Rockies.
Origin: Native
Flowers: May-August
Wild turnip (Brassica rapa)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots and other disturbed open areas.
Origin: Introduced from Europe
Flowers: April-Septemeber
Tutsan (Hypericum androsaemum)
Origin: Introduced from Europe
Broad-lip twayblade (Neottia convallarioides)
Distribution: Occurring on both sides of the Cascades crest in the forested and mountainous areas of Washington; Alaska to California, east to the Rocky Mountains, and from the Great Lakes region to northeastern North America.
Habitat: Moist forests and wet meadows, from low elevations to the subalpine.
Origin: Native
Flowers: June-August
Heart-leaf twayblade (Neottia cordata)
Distribution: Occurring on both sides of the Cascades crest in Washington, but chiefly west of the crest; Alaska to California, east to the Rocky Mountains, further east across Canada to the Great Lakes region and northeastern North America.
Habitat: Humus-rich, often damp, forest understory, sometimes along streams, from low to middle elevations.
Origin: Native
Flowers: May-August
Loesel's twayblade (Liparis loeselii)
Distribution: Occasional, Saskatchewan to Nova Scotia, south to North Dakota and Iowa; Klickitat and Yakima Counties in Washington.
Habitat: Around springs and in bogs.
Origin: Native
Flowers: July - August
Northern twayblade (Neottia borealis)
Distribution: Known only from Okanogan County in Washington; Alaska south to Oregon, east to northern Rocky Mountains, east across Canada to the Atlantic Coast.
Habitat: Moist, rich coniferous forest understory.
Origin: Native
Flowers: June-July
Northwestern twayblade (Neottia banksiana)
Distribution: Occurring on both sides of the Cascades in Washington; Alaska to California, east to Alberta and Wyoming.
Habitat: Moist forests and wet meadows, lowlands to subalpine elevations
Origin: Native
Flowers: June-August
Black twin-berry (Lonicera involucrata)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains.
Habitat: Forest openings and edge, thickets, and marshes from low elevations to the subalpine.
Origin: Native
Flowers: April-August
Twinflower (Linnaea borealis)
Distribution: Widely distributed in forested and mountainous areas on both sides of the Cascades crest in Washington; Alaska to California, east in North America to the Atlantic Coast; circumboreal.
Habitat: Open forest, forest edges, and peatlands from low elevations to the alpine.
Origin: Native
Flowers: May-September
Alpine twinpod (Physaria alpestris)
Distribution: Occurring east of the Cascades crest in Washington, where endemic to Chelan, Kittitas and Yakima counties.
Habitat: Open rocky areas, scree and talus slopes, middle to high elevations in the mountains.
Origin: Native
Flowers: April-July
Common twinpod (Physaria didymocarpa)
Origin: Native
Flowers: June - August
Geyer's twinpod (Physaria geyeri)
Distribution: Occurring in eastern portion of Washington; Washington east to Idaho and Montana.
Habitat: Gravelly stream banks and hillsides.
Origin: Native
Flowers: May-July
Oregon twinpod (Physaria oregona)
Distribution: Occurring in southeastern corner of Washington; Washington east to Idaho, south to Oregon.
Habitat: Dry areas including rocky slopes, gravel banks, and stream shores.
Origin: Native
Flowers: April-June
Washington twinpod (Physaria alpestris)
Distribution: Occurring east of the Cascades crest in Washington, where endemic to Chelan, Kittitas and Yakima counties.
Habitat: Open rocky areas, scree and talus slopes, middle to high elevations in the mountains.
Origin: Native
Flowers: April-July
Clasp-leaf twisted-stalk (Streptopus amplexifolius)
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
Clasping twisted-stalk (Streptopus amplexifolius)
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