Annual hairgrass (Deschampsia danthonioides)
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska to California, east to the the Rocky Mountains; apparently introduced in Alaska, Yukon Territory, Arizona, New Mexico, and the eastern U.S.; disjunct in Chile and Argentina.
Habitat: Mesic to damp open slopes, ledges, vernal pools, scablands, stream banks, and roadsides.
Origin: Native
Flowers: May-July
Growth Duration: Annual

Gray hairgrass (Corynephorus canescens)
Distribution: Occurring west of the Cascades crest in Washington; southwestern British Columbia to northwestern Washington.
Habitat: Moist disturbed, open areas at low elevations.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Annual

Silver hairgrass (Aira caryophyllea)
Distribution: Occurring west of the Cascades crest in Washington and east in the Columbia River Gorge; British Columbia to California, east to Idaho and Wyoming, also in the southeastern U.S. and northeastern North America.
Habitat: Balds, prairies, meadows, forest openings, roadsides, wastelots, and other open areas at low to middle elevations.
Origin: Introduced Eurasia and North Africa
Flowers: May-August
Growth Duration: Annual

Tufted hairgrass (Deschampsia cespitosa)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the northern Great Plains, Great Lakes region, and eastern North America.
Habitat: From coastal marshes and moist prairies to alpine ridges, talus slopes, mountain meadows, and moist areas in the mountains in general.
Origin: Native
Flowers: June-September
Growth Duration: Perennial

Halogeton (Halogeton glomeratus)
Distribution: Occurring east of the Cascades crest in Washington; Washington to California, east to the Rocky Mountains.
Habitat: Fields, roadsides, wastelots, and other distrubed areas.
Origin: Introduced from Eurasia
Flowers: July-September
Growth Duration: Annual

Hardheads (Rhaponticum repens)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across most of North America to the Atlantic Coast.
Habitat: Disturbed dry slopes, meadows, fields, forest openings, and other disturbed, open places from low to middle elevations.
Origin: Introduced from central Asia
Flowers: June-September
Growth Duration: Perennial

Parry's harebell (Campanula parryi)
Distribution: Occurring in the Cascades Range and Olympic Mountains in Washington, where disjunct; central Idaho and adjacent Montana south in Rocky Mountains to Arizona and New Mexico.
Habitat: In subalpine and alpine areas.
Origin: Native
Flowers: July-August
Growth Duration: Perennial

Rover harebell (Campanula rapunculoides)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to Oregon, east across much of North America to the Atlantic Coast.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial

Autumn hawkbit (Leontodon autumnalis)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to Oregon, east to Idaho and Montana; also in eastern North America.
Habitat: Roadsides, pastures, open fields and other disturbed areas primarily in the lowlands, but also found along roads at alpine elevations in the mountains (e.g., Mt. Baker area).
Origin: Introduced from Eurasia
Flowers: July-September
Growth Duration: Perennial

Annual hawksbeard (Crepis tectorum)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; Alaska to California, east across the northern regions of the U.S. and Canada to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed, open areas.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Annual

Bearded hawksbeard (Crepis barbigera)
Distribution: Occurring east of the Cascades crest in Washington; Washington to Oregon, east to Idaho.
Habitat: Sagebrush deserts to ponderosa pine forest openings at middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Dandelion hawksbeard (Crepis runcinata)
Distribution: Occurring east of the Cascades crest in Washington; southeastern British Columbia to California, east to the Great Plains.
Habitat: Moist to dry meadows, marshes, seeps, shores, riverbanks, often where alkaline, from the lowlands to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Gray hawksbeard (Crepis intermedia)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Open forest, grassland, meadows, rocky or sandy slopes, and ridges from low to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Limestone hawksbeard (Crepis intermedia)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
Habitat: Open forest, grassland, meadows, rocky or sandy slopes, and ridges from low to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Low hawksbeard (Askellia pygmaea)
Distribution: Occurring in the Olympic and Cascades mountains in Washington; Alaska to California, east to Nunavut and Colorado, also in northeastern Canada; Asia.
Habitat: Talus, scree, moraines, sandy or gravelly slopes, subalpine to alpine.
Origin: Native
Flowers: July-September
Growth Duration: Perennial

Meadow hawksbeard (Crepis runcinata)
Distribution: Occurring east of the Cascades crest in Washington; southeastern British Columbia to California, east to the Great Plains.
Habitat: Moist to dry meadows, marshes, seeps, shores, riverbanks, often where alkaline, from the lowlands to middle elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Narrow leaf hawksbeard (Crepis tectorum)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; Alaska to California, east across the northern regions of the U.S. and Canada to the Atlantic Coast.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed, open areas.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Annual

Rough hawksbeard (Crepis setosa)
Distribution: Occurring west of the Cascades crest in southwestern Washington; southwestern British Columbia to California, also in Montana and eastern U.S.
Habitat: Roadsides, fields, ditches, wastelots, and other disturbed open areas at low elevations.
Origin: Introduced
Flowers: June-August
Growth Duration: Annual

Smooth hawksbeard (Crepis capillaris)
Distribution: Occurring chiefly west 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, ditches, wastelots, and other disturbed, open areas at low elevation.
Origin: Introduced from Europe
Flowers: May-November
Growth Duration: Annual, Biennial

Turkish hawksbeard (Crepis nicaeensis)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; southwestern British Columbia to southwestern Oregon, also in western Montana, the Great Lakes region, and northeastern North America.
Habitat: Roadsides, fields, pastures, forest openings, and other disturbed areas, often where at least seasonally moist.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Annual

Alpine hawkweed (Hieracium triste)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains of Canada and the U.S.
Habitat: Meadows and other open places in the mountains, usually at high elevations.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

English hawkweed (Hieracium lachenalii)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to northern Oregon; also in eastern North America.
Habitat: Open forest, fields, shores, wastelots, and other disturbed areas generally at low to middle elevations.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial

Flowery hawkweed (Hieracium ×floribundum)
Distribution: Occurring in scattered locations in lowland western Washington; Washington east to Montana and Wyoming; eastern North America.
Habitat: Disturbed areas at low elevations.
Origin: Introduced
Flowers: May-July
Growth Duration: Perennial

Hound-tongue hawkweed (Hieracium scouleri)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, Wyoming, and Utah.
Habitat: Mostly dry places in open woods, from foothills to middle elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Meadow hawkweed (Hieracium caespitosum)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to Oregon, east to Idaho, Montana, and Wyoming; also occurring throughout eastern North America.
Habitat: Moist pastures, forest openings, roadsides, and springs, from the lowlands to middle elevations in the mountains, usually where disturbed.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial

Mouse-ear hawkweed (Hieracium pilosella)
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Oregon; also in northeastern North America.
Habitat: Roadsides, dry prairies, quarries, lawns, railroads, and other disturbed, open sites.
Origin: Introduced from Europe
Flowers: April-August
Growth Duration: Perennial

Orange hawkweed (Hieracium aurantiacum)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east across southern Canada and northern U.S; widely distributed throughout eastern U.S.
Habitat: Roadsides, fields, meadows, pastures, forest edge, wastelots, and other disturbed areas at low to middle elevations.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial

Scouler's hawkweed (Hieracium scouleri)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Montana, Wyoming, and Utah.
Habitat: Mostly dry places in open woods, from foothills to middle elevations in the mountains.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Tall hawkweed (Hieracium piloselloides)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to northeastern Oregon.
Habitat: Roadsides, meadows, forest openings, and other disturbed areas.
Origin: Introduced from Europe
Flowers: June-August
Growth Duration: Perennial

Wall hawkweed (Hieracium murorum)
Distribution: Occurring in scattered locations west of the Cascades crest in Washington; southern British Columbia to northern Oregon.
Habitat: Roadsides, open forest, railroads, and other disturbed areas.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial

White hawkweed (Hieracium albiflorum)
Distribution: Widely distributed in forested areas on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and eastern Canada.
Habitat: Open woods from low to middle elevations.
Origin: Native
Flowers: June-September
Growth Duration: Perennial

Yellow devil hawkweed (Hieracium glomeratum)
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to Washington.
Habitat: Open forest, meadows, disturbed ground, roadsides, stream banks, and gravel pits generally at low elevations.
Origin: Introduced from Europe
Flowers: May-August
Growth Duration: Perennial

Castlegar hawthorn (Crataegus castlegarensis)
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east to Idaho, Montana, and Utah.
Habitat: Grasslands, riparian zones, thickets, openings, and seeps.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

English hawthorn (Crataegus monogyna)
Distribution: Occurring chiefly west of the Cascades crest in Washington; southern British Columbia to California, east to Montana, also in the Great Lakes region and eastern North America.
Habitat: Roadsides, fields, pastures, meadows, thickets, and forest edge and understory at low elevations, often associated with disturbance. Seeds readily dispersed by birds.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial

Huckleberry hawthorn (Crataegus gaylussacia)
Distribution: Occurring on both sides of the Cascades crest in Washington; disjunct in southeast Alaska, otherwise southern British Columbia to California, east to Montana.
Habitat: Thickets, grasslands, riparian zones, shores, and meadows, from lowl to middle elevations in the mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Midland hawthorn (Crataegus laevigata)
Distribution: Known only from the San Juan Islands in Washington.
Origin: Introduced from northern Europe
Growth Duration: Perennial

Okanagan hawthorn (Crataegus okanaganensis)
Distribution: Occurring east of the Cascades crest in Washington in northern Washington; southern British Columbia to northern Washington, east to northern Idaho.
Habitat: Mesic thickets, riparian zones, and shorelines.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Oregon hybrid hawthorn (Crataegus ×cogswellii)
Distribution: Occurring west of the Cascades crest in Washington; western Washington to the Willamette Valley in Oregon.
Habitat: Wet prairie, thickets, and shores, generally occurring near where both parent species occur.
Origin: Introduced
Flowers: May-July
Growth Duration: Perennial

Slender red hawthorn (Crataegus tenuior)
Distribution: Occurring east of the Cascades crest in north-central Washington; south-central British Columbia to north-central Washington.
Habitat: Grasslands, thickets, and forest openings.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Western large-thorned hawthorn (Crataegus macracantha)
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to northeastern Oregon, east to the Rocky Mountains, and further east across the U.S. and Canada to the Atlantic Coast.
Habitat: Thickets, riparian zones, and pastures.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Beaked hazelnut (Corylus cornuta)
Distribution: Occurring on both sides of the Cascades crest in Washington; southern British Columbia to California, east to the Rocky Mountains, northern Great Plains, Great Lakes region, and eastern North America.
Habitat: Forest edge and openings, thickets, and rocky slopes at low to middle elevations.
Origin: Native
Flowers: January-March
Growth Duration: Perennial

Heartweed (Persicaria maculosa)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Habitat: A weedy species, usually on moist, cultivated or otherwise disturbed soil.
Origin: Introduced from Eurasia
Flowers: March-September
Growth Duration: Perennial

Mountain heath-grass (Danthonia decumbens)
Distribution: Occurring west of the Cascades crest in southwestern Washington; southwestern British Columbia to California; also in northeastern Canada.
Habitat: Marshy margins, dunes, dry meadows, damp, disturbed ground.
Origin: Introduced from Europe
Flowers: July-September
Growth Duration: Perennial

Common heather (Calluna vulgaris)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California, also along the Atlantic Coast.
Habitat: Disturbed, open areas, where escaping from cultivation.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial

Bractless hedge-hyssop (Gratiola ebracteata)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east to western Montana.
Habitat: Shallow water and muddy shores, and in other wet places in the valleys and plains.
Origin: Native
Flowers: May-August
Growth Duration: Annual

Cooley's hedge-nettle (Stachys cooleyae)
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
Growth Duration: Perennial

Mexican hedge-nettle (Stachys mexicana)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California.
Habitat: Forest understory, openings, and margins, often where moist.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Swamp hedge-nettle (Stachys pilosa)
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska to California, east across much of North America to the Atlantic Coast.
Habitat: Swamps, marshes, wetlands and riparian areas.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

False hedge-parsley (Yabea microcarpa)
Distribution: Occurring on both sides of the Cascades crest in Washington and in the Columbia River Gorge. British Columbia to Baja California, east to Idaho, Utah, and New Mexico.
Habitat: Along streams, open woodlands, and vernally moist slopes at low elevations.
Origin: Native
Flowers: April-June
Growth Duration: Annual

Japanese hedge-parsley (Torilis japonica)
Distribution: Occurring chiefly west of the Cascades crest in Washington; southwestern British Columbia to California, also in south-central and eastern North America.
Habitat: Forest understory and edge, thickets, fields, roadsides, wastelots, and other disturbed areas at low elevations.
Origin: Introduced
Flowers: April-July
Growth Duration: Annual

Rocky Mountain helianthella (Helianthella uniflora)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon and Nevada, east to the Rocky Mountains.
Habitat: Dry, open woods and meadows from low to middle elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Seaside heliotrope (Heliotropium curassavicum)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Saline places at low evelevations, often in the beds of dried ponds.
Origin: Native
Flowers: June-September
Growth Duration: Annual, Perennial

Stinking hellebore (Helleborus foetidus)
Distribution: Currently only known from lowland western Washington.
Habitat: Disturbed sites near urban or suburban areas, where escaped from cultivation.
Origin: Introduced from Eurasia
Flowers: February-April
Growth Duration: Perennial

Garden helleborine (Epipactis helleborine)
Distribution: Occurring west of the Cascades crest in lowland areas in Washington; British Columbia to California, in scattered locations across North America to the Atlantic Coast, where more common.
Habitat: Moist to dry forest edge and understory, often where disturbed.
Origin: Introduced from Eurasia
Flowers: June-October
Growth Duration: Perennial

Hellroot (Orobanche minor)
Distribution: Occurring in scattered locations west of the Cascades crest in Washington; Washington to Oregon, and reported from Idaho; also in Texas and along the East Coast of the U.S.
Habitat: Lawns, fields, pastures, forest edge, and other grassy areas at low elevations.
Origin: Introduced from Europe
Flowers: May-July
Growth Duration: Annual

Mountain hemlock (Tsuga mertensiana)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to Montana.
Habitat: Middle to high elevations in the mountains
Origin: Native
Cones: June-July (cones)
Growth Duration: Perennial

Pacific hemlock-parsley (Conioselinum pacificum)
Distribution: Occurring west of the Cascades crest along the marine coast in Washington; Alaska to California.
Habitat: Bluffs and rocky or sandy beaches along the seashore.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

Bifid hemp nettle (Galeopsis bifida)
Distribution: Occurring east of the Cascades crest, where known from Kittitas County in Washington; Alaska to Washington, east across the northern U.S. and Canada to Atlantic Coast.
Habitat: Disturbed areas, roadsides, and irrigation channels.
Origin: Introduced from Eurasia
Flowers: July-August
Growth Duration: Perennial

Fat hen (Atriplex prostrata)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, in scattered location across Canada and the U.S. to the Atlantic Coast.
Habitat: Along the coast in saline soils, beaches, and strands; inland in alkaline soils.
Origin: Introduced from Eurasia
Flowers: June-September
Growth Duration: Annual

Black henbane (Hyoscyamus niger)
Distribution: Occurring chiefly east of the Cascades crest in Washington; Washington to Oregon, east across much of North America to the Atlantic Coast.
Habitat: Roadsides and waste places.
Origin: Introduced from Europe
Flowers: May-August
Growth Duration: Annual

Spotted henbit (Lamium maculatum)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to Oregon, east to Idaho; also in eastern North America.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Eurasia
Flowers: April-August
Growth Duration: Perennial

Herb-Robert (Geranium robertianum)
Distribution: Occurring west of the Cascades crest and in the Columbia River Gorge in Washington; Alaska to California, east to Montana, further east in Canada, the Great Lakes region, and eastern North America.
Habitat: Forest understory and forest edges, riparian zones, and other lowland areas with natural or man-made disturbances.
Origin: Introduced from Europe
Flowers: March-August
Growth Duration: Annual, Biennial

Small hesperochiron (Hesperochiron pumilus)
Distribution: Occurring east of the Cascade crest in Washington; Washington to California, east to the Rocky Mountains.
Habitat: Meadows and moist, open slopes from the foothills to moderate elevations in the mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Hoary-aster (Dieteria canescens)
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to southern California, east to the Great Plains.
Habitat: Dry, open places in the plains and foothills, occasionally extending into the mountains.
Origin: Native
Flowers: July-October
Growth Duration: Perennial

Globepodded hoarycress (Lepidium appelianum)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to the northern Great Plains, Great Lakes region, and eastern U.,S.
Habitat: Disturbed soil, waste areas, in dry and moist places.
Origin: Introduced from Asia
Flowers: April-August
Growth Duration: Perennial

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

American hogweed (Heracleum maximum)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across North America except in the southeastern U.S.
Habitat: Moist areas, including meadows and forest edge from low to middle elevations.
Origin: Native
Flowers: June-August
Growth Duration: Perennial

English holly (Ilex aquifolium)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California, also in scattered locations in eastern North America.
Habitat: Spread by birds, mostly forested areas at low elevations.
Origin: Introduced from Europe
Flowers: April-June
Growth Duration: Perennial

Vancouver holly-fern (Polystichum andersonii)
Distribution: Occurring chiefly west of the Cascades crest in Washington; southern Alaska to northern Oregon, northern Idaho, and northwest Montana.
Habitat: Deep woods and thickets in the mountains.
Origin: Native
Growth Duration: Perennial

Honesty (Lunaria annua)
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to California and Utah; also distributed throughout eastern North America.
Habitat: Escaping from cultivation to urban forests, roadsides, and other disturbed areas.
Origin: Introduced from southeast Europe
Flowers: March-June
Growth Duration: Annual

Bearberry honeysuckle (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
Growth Duration: Perennial

Etruscan honeysuckle (Lonicera etrusca)
Distribution: Occasional west of the Cascades crest in Washington; southern British Columbia to Oregon.
Habitat: Thickets, forest edge, wastelots, and other disturbed areas.
Origin: Introduced from the Mediterranean region
Flowers: June-August
Growth Duration: Perennial

Japanese honeysuckle (Lonicera japonica)
Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; Washington to California, scattered eastward across the U.S. to the Atlantic Coast.
Habitat: Disturbed areas, woods, and thickets.
Origin: Introduced from Asia
Flowers: May-July
Growth Duration: Perennial

Pink honeysuckle (Lonicera hispidula)
Distribution: Occurring west of the Cascades crest in lowland western Washington; British Columbia to California.
Habitat: Forest understory and edge, thickets, balds, and open woodlands at low elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Purple-flower honeysuckle (Lonicera conjugialis)
Distribution: Occurring chiefly east of the Cascades crest in Washington mostly from Mt. Adams south, though a historical record is known from Yakima County; south-central Washington to the Sierra Nevada of California.
Habitat: In woods, meadows and moist open slopes at mid-elevations in the mountains.
Origin: Native
Flowers: June-July
Growth Duration: Perennial

Showy fly honeysuckle (Lonicera ×bella)
Distribution: Occurring on both sides of the Cascades crest in Washington; southern British Columbia to Oregon and Idaho, scattered localities in central North America, and more widespread in eastern North America.
Habitat: Forest edge and understory, riparian areas, and disturbed areas at low to moderate elevations.
Origin: Introduced
Flowers: April-June
Growth Duration: Perennial

Tartarian honeysuckle (Lonicera tatarica)
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across much of North America to the Atlantic Coast.
Habitat: Disturbed areas, woods, and thickets.
Origin: Introduced from Eurasia
Flowers: May-July
Growth Duration: Perennial

Hops (Humulus lupulus)
Distribution: Occurring on both sides of the Cascades crest in Washington; occasionally escaped from cultivation in many areas in North America.
Habitat: Fields, thickets, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Eurasia
Flowers: July-August
Growth Duration: Perennial

White horehound (Marrubium vulgare)
Distribution: Occurring on both sides of the Cascades crest in Washington Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Fields, roadsides, thickets, wastelots, and other disturbed areas.
Origin: Introduced from Eurasia
Flowers: June-October
Growth Duration: Perennial

Horse-chestnut (Aesculus hippocastanum)
Distribution: Occurring chiefly west of the Cascades crest in Washington; British Columbia to Oregon, also in central and eastern North America.
Habitat: Disturbed forested areas, particularly in urban and suburban areas where the species is planted as a street tree.
Origin: Introduced from Europe
Flowers: May-June
Growth Duration: Perennial

White horse-nettle (Solanum elaeagnifolium)
Distribution: Occurring east of the Cascades crest in southeastern Washington; Washington to California, east across the southern half of the U.S. to the Atlantic Coast.
Habitat: Fields, roadsides, wastelots, and other disturbed areas.
Origin: Introduced from Mexico and eastern United States
Flowers: June-August
Growth Duration: Perennial

Spineless horsebrush (Tetradymia canescens)
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to California, east to the Rocky Mountains.
Habitat: Dry, open places in sagebrush.
Origin: Native
Flowers: June-September
Growth Duration: Perennial

Common horsetail (Equisetum arvense)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across North America, except for the south-central and southeastern U.S., to the Atlantic Coast.
Habitat: Moist to moderately dry, often disturbed places, from the lowlands to the subalpine.
Origin: Native
Spores: April-July
Growth Duration: Perennial

Field horsetail (Equisetum arvense)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east across North America, except for the south-central and southeastern U.S., to the Atlantic Coast.
Habitat: Moist to moderately dry, often disturbed places, from the lowlands to the subalpine.
Origin: Native
Spores: April-July
Growth Duration: Perennial

Marsh horsetail (Equisetum palustre)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across the northern U.S. and Canada to the Atlantic Coast; circumboreal.
Habitat: Streambanks, wet meadows, and marshes, from the lowlands to moderate elevations in the mountains.
Origin: Native
Growth Duration: Perennial

River horsetail (Equisetum fluviatile)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon, east to the northern Rocky Mountains and northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Shallow water, marshes and bogs, along muddy shores, from the lowlands to moderate elevations in the mountains.
Origin: Native
Spores: April-July
Growth Duration: Perennial

Sedgelike horsetail (Equisetum scirpoides)
Distribution: Occurring east of the Cascades crest in northeastern Washington; Alaska to Washington, east across the northern U.S.and Canada to the Atlantic Coast; circumboreal.
Habitat: Moist, swampy places, especially in coniferous forests.
Origin: Native
Growth Duration: Perennial

Swamp horsetail (Equisetum fluviatile)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon, east to the northern Rocky Mountains and northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Shallow water, marshes and bogs, along muddy shores, from the lowlands to moderate elevations in the mountains.
Origin: Native
Spores: April-July
Growth Duration: Perennial

Water horsetail (Equisetum fluviatile)
Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to Oregon, east to the northern Rocky Mountains and northern Great Plains, Great Lakes region, and northeastern North America.
Habitat: Shallow water, marshes and bogs, along muddy shores, from the lowlands to moderate elevations in the mountains.
Origin: Native
Spores: April-July
Growth Duration: Perennial

Woodland horsetail (Equisetum sylvaticum)
Distribution: Occurring east of the Cascades crest in the northeastern counties in Washington; Alaska to Washington, east across southern Canada and the northern United States to the Atlantic Coast; circumboreal.
Habitat: Shady coniferous forests, bog edges, and swamps
Origin: Native
Growth Duration: Perennial

Adeline's hound's-tongue (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
Growth Duration: Perennial

Pacific hound's-tongue (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
Growth Duration: Perennial

Blueleaf huckleberry (Vaccinium deliciosum)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Idaho.
Habitat: Forest openings and mountain meadows, mid- to high elevations.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Evergreen huckleberry (Vaccinium ovatum)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia to California.
Habitat: Coniferous forests at low elevations.
Origin: Native
Flowers: April-August
Growth Duration: Perennial

Red huckleberry (Vaccinium parvifolium)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California.
Habitat: Moist woods, forest edges and openings, from sea level to middle elevations in the mountains.
Origin: Native
Flowers: April-June
Growth Duration: Perennial

Thin-leaved huckleberry (Vaccinium membranaceum)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains and Great Lakes region.
Habitat: Common in dry to moist coniferous forests and open areas, moderate to mid-elevations in the mountains.
Origin: Native
Flowers: May-July
Growth Duration: Perennial

Hungerweed (Ranunculus arvensis)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to California, east to Idaho and Utah; also in areas of central and eastern U.S.
Habitat: Dry woodlands and waste ground.
Origin: Introduced from Europe
Flowers: May-June
Growth Duration: Annual

Prostrate hutchinsia (Hornungia procumbens)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains, central Canada, and Newfoundland.
Habitat: Open areas where seasonally moist.
Origin: Introduced from Europe, North Africa, and Asia
Flowers: March-June
Growth Duration: Annual

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

Wild hyssop (Verbena hastata)
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.
Habitat: Marshes, wetlands, streamsides, and other riparian areas.
Origin: Native
Flowers: July-September
Growth Duration: Biennial, Perennial