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 H:
Netleaf hackberry (Celtis reticulata)
Distribution: Primarily along the Columbia River and Snake River in Washington; Washington south to California, east through Southern Rockies to Kansas, Oklahoma and Texas.
Habitat: Open slopes and rocky bluffs.
Origin: Native
Flowers: April-May
Beringian hairgrass (Deschampsia cespitosa)
Distribution: Widely distributed throughout Washington; widely distributed throughout 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
Delicate hairgrass (Aira elegans)
Origin: Introduced
Silver hairgrass (Aira caryophyllea)
Distribution: Introduced and common west of the Cascades, British Columbia to California
Habitat: A weed in moist to dry, gravelly soil
Origin: Introduced
Flowers: May - August
Tufted hairgrass (Deschampsia cespitosa)
Distribution: Widely distributed throughout Washington; widely distributed throughout 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
Puzzling halimolobos (Sandbergia perplexa)
Distribution: Known from Douglas County in Washington; Washington east toIdaho and Montana.
Habitat: Sagebrush desert, typically on lithosol.
Origin: Native
Flowers: April-June
Halogeton (Halogeton glomeratus)
Origin: Introduced from Eurasia
Flowers: July - September
Hardheads (Centaurea nigra)
Distribution: Introduced in the Pacific Northwest and northeastern United States
Habitat: Uncommon weed in disturbed soil
Origin: Introduced from Europe
Flowers: July - October
Hardheads (Rhaponticum repens)
Distribution: Introduced chiefly east of the Cascades in Washington; widely distributed throughout much of North America.
Habitat: Dry, open areas at low elevation and foothills.
Origin: Introduced
Flowers: June-September
Alaska harebell (Campanula lasiocarpa)
Distribution: Local in Washington to western Cascades of Puget Trough; Alaska south to Washington, east to Northwest Territories and Alberta.
Habitat: Uncommon in meadows at high elevations in the mountains
Origin: Native
Flowers: July-August
Parry's harebell (Campanula parryi)
Distribution: Local in Olympic and Cascade Mountains of Washington; central and northern Idaho and adjacent Montana.
Habitat: High elevations in the mountains.
Origin: Native
Flowers: July-August
Rough harebell (Campanula scabrella)
Distribution: In the Cascades of Washington; Washington south to California, east to Idaho and Montana.
Habitat: Open, rocky areas at high elevations.
Origin: Native
Flowers: June-August
Rover harebell (Campanula rapunculoides)
Distribution: Introduced garden species, often escaping in scattered localities across Washington; British Columbia to Oregon.
Habitat: Moist soil at low elevations
Origin: Introduced
Flowers: June-August
Slender hareleaf (Lagophylla ramosissima)
Distribution: Occurring east of the Cascades in Washington; Washington south to California, east to Montana, Idaho, and Nevada.
Habitat: Dry, open areas of foothills and plains.
Origin: Native
Flowers: May-July
Autumn hawkbit (Leontodon autumnalis)
Distribution: Known from San Juan and Whatcom counties 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
Hairy hawkbit (Leontodon saxatilis)
Distribution: Occurring in scattered locations in Washington, chiefly west of the Cascades crest; British Columbia south to California, Nevada, and Arizona; central and eastern U.S.
Habitat: Disturbed sites.
Origin: Introduced
Flowers: July-September
Annual hawksbeard (Crepis tectorum)
Distribution: Introduced from Alaska to California, and across much of the northern half on the United States
Habitat: Uncommon in lawns and wastelands
Origin: Introduced from Europe
Flowers: June - July
Baker's hawksbeard (Crepis bakeri)
Distribution: East slope of the Cascades, from central Washington to central California.
Habitat: Dry, open slopes in the foothills and at moderate elevations in the mountains.
Origin: Native
Flowers: May
Bearded hawksbeard (Crepis barbigera)
Distribution: Occurring chiefly east of the Cascades crest in Washington; Washington south to Oregon, east to Idaho.
Habitat: Dry, open areas in the plains and foothills.
Origin: Native
Flowers: May-July
Bristly hawksbeard (Crepis setosa)
Distribution: West of the Cascades in Washington, south to California
Habitat: Disturbed areas at low elevation
Origin: Introduced
Flowers: June-August
Dandelion hawksbeard (Crepis runcinata)
Origin: Native
Flowers: May - July
French hawksbeard (Crepis nicaeensis)
Origin: Introduced from Europe
Gray hawksbeard intermediate hawksbeard (Crepis intermedia)
Distribution: British Columbia to California, east to Montana and Arizona
Habitat: Somewhat moist to dry open areas, foothills to moderate elevations
Origin: Native
Flowers: May - July
Limestone hawksbeard (Crepis intermedia)
Distribution: British Columbia to California, east to Montana and Arizona
Habitat: Somewhat moist to dry open areas, foothills to moderate elevations
Origin: Native
Flowers: May - July
Long leaved hawksbeard (Crepis acuminata)
Distribution: East of the Cascades, Washington to California, east to Montana and New Mexico.
Habitat: Dry, open places from the foothiils to moderate elevations in the mountains.
Origin: Native
Flowers: May - July
Low hawksbeard (Askellia pygmaea)
Distribution: Occurring in the Olympic and Cascades mountains in Washington; Alaska to California, east to Nunavut, Alberta, Montana, Wyoming, and CO; northeastern North America; Asia.
Habitat: Uncommon above timberline in the mountains.
Origin: Native
Flowers: July-August
Low hawksbeard (Crepis modocensis)
Distribution: East of the Cascades in Washington; British Columbia south to Oregon.
Habitat: Common in shrub-steppe, sagebrush, and forest openings.
Origin: Native
Flowers: May-July
Meadow hawksbeard (Crepis runcinata)
Origin: Native
Flowers: May - July
Modoc hawksbeard (Crepis modocensis)
Distribution: East of the Cascades in Washington; British Columbia south to Oregon.
Habitat: Common in shrub-steppe, sagebrush, and forest openings.
Origin: Native
Flowers: May-July
Naked stemmed hawksbeard (Crepis pleurocarpa)
Distribution: In eastern portion of Washington; south to California, east to Idaho and Nevada.
Habitat: Stream banks in mixed conifer forests, road cuts, and rocky, serpentine soils.
Origin: Native
Flowers: June-August
Narrow leaf hawksbeard (Crepis tectorum)
Distribution: Introduced from Alaska to California, and across much of the northern half on the United States
Habitat: Uncommon in lawns and wastelands
Origin: Introduced from Europe
Flowers: June - July
Rooftop hawksbeard (Crepis tectorum)
Distribution: Introduced from Alaska to California, and across much of the northern half on the United States
Habitat: Uncommon in lawns and wastelands
Origin: Introduced from Europe
Flowers: June - July
Rough hawksbeard (Crepis setosa)
Distribution: West of the Cascades in Washington, south to California
Habitat: Disturbed areas at low elevation
Origin: Introduced
Flowers: June-August
Slender hawksbeard (Crepis atribarba)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to Nevada, east to the Great Plains of Canada and the U.S.
Habitat: Dry, open places, foothills to moderate elevations in the mountains.
Origin: Native
Flowers: May-July
Smooth hawksbeard (Crepis capillaris)
Distribution: Occurring chiefly west of the Cascades in Washington; widely distributed throughout much of North America.
Habitat: Disturbed soil at lower elevations.
Origin: Introduced from Europe
Flowers: May-November
Tapertip hawksbeard (Crepis acuminata)
Distribution: East of the Cascades, Washington to California, east to Montana and New Mexico.
Habitat: Dry, open places from the foothiils to moderate elevations in the mountains.
Origin: Native
Flowers: May - July
Turkish hawksbeard (Crepis nicaeensis)
Origin: Introduced from Europe
Western hawksbeard (Crepis occidentalis)
Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east to the Great Plains of Canada and the U.S.
Habitat: Dry, open places, mostly in the foothills and plains.
Origin: Native
Flowers: May-July
Alpine hawkweed (Hieracium triste)
Distribution: Occurring throughout the mountainous areas in Washington; Alaska south to California, east 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
Common hawkweed (Hieracium lachenalii)
Distribution: Uncommon introduction west of the Cascades in Washington and Oregon
Habitat: Disturbed areas
Origin: Introduced from Europe
Flowers: June - August
English hawkweed (Hieracium lachenalii)
Distribution: Uncommon introduction west of the Cascades in Washington and Oregon
Habitat: Disturbed areas
Origin: Introduced from Europe
Flowers: June - August
European hawkweed (Hieracium lachenalii)
Distribution: Uncommon introduction west of the Cascades in Washington and Oregon
Habitat: Disturbed areas
Origin: Introduced from Europe
Flowers: June - August
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
Forked hawkweed (Hieracium stoloniflorum)
Origin: Introduced from Europe
Hound tongue hawkweed (Hieracium scouleri)
Distribution: Widely distributed throughout Washington; British Columbia south to California, chiefly in the Cascade-Sierra Nevada region.
Habitat: Mostly dry places in open woods, foothills to moderate or sometimes higher elevations in the mountains.
Origin: Native
Flowers: June-August
Long bearded hawkweed (Hieracium longiberbe)
Distribution: Columbia River Gorge, Washington and Oregon.
Habitat: Hillsides and rock crevices.
Origin: Native
Flowers: June - July
Meadow hawkweed (Hieracium caespitosum)
Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia south to Washington, east to Idaho, Montana, and Wyoming; also occurring throughout eastern North America.
Habitat: Moist places from the lowlands to moderate elevations in the mountains, usually where the soil has been disturbed.
Origin: Introduced from Europe
Flowers: June-August
Mottled hawkweed (Hieracium maculatum)
Origin: Introduced from Europe
Mouse ear hawkweed (Hieracium pilosella)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to Oregon; northeastern North America.
Habitat: Disturbed areas, forest openings, prairies, meadows, and roadsides.
Origin: Introduced from Europe
Flowers: June-August
Narrowleaf hawkweed (Hieracium umbellatum)
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska south to northwest Oregon, east across the northern half of North America to the Atlantic Coast; circumboreal.
Habitat: Moist places in thickets and open woods.
Origin: Native
Flowers: July-September
Orange hawkweed (Hieracium aurantiacum)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east across southern Canada and northern U.S; widely distributed throughout eastern U.S.
Habitat: Moist sites from lowlands to mid-elevations in the mountains, typically where disturbed.
Origin: Introduced from Europe
Flowers: June-August
Savoy hawkweed (Hieracium sabaudum)
Origin: Introduced from Europe
Scouler's hawkweed (Hieracium scouleri)
Distribution: Widely distributed throughout Washington; British Columbia south to California, chiefly in the Cascade-Sierra Nevada region.
Habitat: Mostly dry places in open woods, foothills to moderate or sometimes higher elevations in the mountains.
Origin: Native
Flowers: June-August
Slender hawkweed (Hieracium triste)
Distribution: Occurring throughout the mountainous areas in Washington; Alaska south to California, east 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
Tall hawkweed (Hieracium piloselloides)
Origin: Introduced from Europe
Umbellate hawkweed (Hieracium umbellatum)
Distribution: Occurring chiefly east of the Cascades crest in Washington; Alaska south to northwest Oregon, east across the northern half of North America to the Atlantic Coast; circumboreal.
Habitat: Moist places in thickets and open woods.
Origin: Native
Flowers: July-September
Wall hawkweed (Hieracium murorum)
Distribution: In scattered locations in lowland western Washington; British Columbia south to Washington; occurring throughout northeastern North America.
Habitat: Distrurbed areas and forest edge.
Origin: Introduced from Europe
Flowers: April-June
Whip hawkweed (Hieracium flagellare)
Origin: Introduced from Europe
White flowered hawkweed (Hieracium albiflorum)
Distribution: British Columbia to California, east to Colorado
Habitat: Open woods at moderate to mid-elevations in the mountains.
Origin: Native
Flowers: June - August
White hawkweed (Hieracium albiflorum)
Distribution: British Columbia to California, east to Colorado
Habitat: Open woods at moderate to mid-elevations in the mountains.
Origin: Native
Flowers: June - August
Yellow devil hawkweed (Hieracium glomeratum)
Origin: Introduced
Black hawthorn (Crataegus douglasii)
Distribution: Both sides of the Cascades, Alaska to California, east to Utah and Wyoming, and across the northern states to Michigan
Habitat: Moist to dry areas, lowlands to moderate elevations
Origin: Native
Flowers: May - June
Castlegar hawthorn (Crataegus castlegarensis)
Origin: Native
Douglas' hawthorn (Crataegus douglasii)
Distribution: Both sides of the Cascades, Alaska to California, east to Utah and Wyoming, and across the northern states to Michigan
Habitat: Moist to dry areas, lowlands to moderate elevations
Origin: Native
Flowers: May - June
English hawthorn (Crataegus monogyna)
Origin: Introduced
Fireberry hawthorn (Crataegus chrysocarpa)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon, east to the Atlantic.
Habitat: Thickets, dry slopes, shrub-steppe, riparian zones, open forests.
Origin: Native
Flowers: May-June
Huckleberry hawthorn (Crataegus gaylussacia)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to Montana and Idaho.
Habitat: Openings and forest margins at low to moderate elevations.
Origin: Native
Flowers: April-June
Large-thorned hawthorn (Crataegus macracantha)
Origin: Native
Midland hawthorn (Crataegus laevigata)
Origin: Introduced from northern Europe
O'Kennon's hawthorn (Crataegus okennonii)
Origin: Native
Okanagan hawthorn (Crataegus okanaganensis)
Origin: Native
One-seed hawthorn (Crataegus monogyna)
Origin: Introduced
Oregon hybrid hawthorn (Crataegus ×cogswellii)
Origin: Introduced
Phipps\\\' hawthorn (Crataegus phippsii)
Origin: Native
Suksdorf hawthorn (Crataegus gaylussacia)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to Montana and Idaho.
Habitat: Openings and forest margins at low to moderate elevations.
Origin: Native
Flowers: April-June
Suksdorf's hawthorn (Crataegus gaylussacia)
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to Montana and Idaho.
Habitat: Openings and forest margins at low to moderate elevations.
Origin: Native
Flowers: April-June
Western large-thorned hawthorn (Crataegus macracantha)
Origin: Native
Woodland hawthorn (Crataegus laevigata)
Origin: Introduced from northern Europe
Beaked hazelnut (Corylus cornuta)
Distribution: Widespread in North America from British Columbia to Newfoundland, south to California, Colorado, Missouri, Ohio, and Georgia. In WA on both sides of the Cascades, and in the eastern portion of the state.
Habitat: Forest edge and openings, thickets, and rocky slopes at low to middle elevations.
Origin: Native
Flowers: January - March
European hazelnut (Corylus avellana)
Distribution: Widely planted as an ornamental and occasionally naturalizing in western Washington lowlands; British Columbia south to Oregon.
Habitat: Abandoned plantings, roadsides, waste sites, forest edge.
Origin: Introduced
Flowers: January-April
Elephant's head (Pedicularis groenlandica)
Distribution: Alaska to California, east to Montana, Colorado and New Mexico
Habitat: Seeps, lake shores and other wet areas at mid- to high elevations in the mountains
Origin: Native
Flowers: June - August
Lion's heart (Lallemantia peltata)
Origin: Introduced
Heartweed (Persicaria maculosa)
Distribution: Occurring throughout much of Washington; widely distributed throughout North America.
Habitat: A weedy species, usually on moist, cultivated or otherwise disturbed soil.
Origin: Introduced
Flowers: March-September
Common heath-grass (Danthonia decumbens)
Origin: Introduced from Europe
Flowers: July - September
Mountain heath-grass (Danthonia decumbens)
Origin: Introduced from Europe
Flowers: July - September
Alpine heather (Harrimanella stelleriana)
Distribution: Alaska to the high Cascades of Washington
Habitat: Rocky slopes and seeps, alpine to subalpine
Origin: Native
Flowers: July - August
American hedge-hyssop (Gratiola neglecta)
Distribution: Occurring on both sides of the Cascades crest in Washington; widely distributed throughout most of North America.
Habitat: In shallow water and on muddy shores, and in other wet places in the valleys and plains.
Origin: Native
Flowers: June-August
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
Clammy hedge-hyssop (Gratiola neglecta)
Distribution: Occurring on both sides of the Cascades crest in Washington; widely distributed throughout most of North America.
Habitat: In shallow water and on muddy shores, and in other wet places in the valleys and plains.
Origin: Native
Flowers: June-August
Cooley's hedge-nettle (Stachys cooleyae)
Distribution: Chiefly west of the Cascades in Washington; Alaska south to California.
Habitat: Forest understory, openings, and margins at low to moderate elevations in the mountains; often where moist.
Origin: Native
Flowers: June-August
Field hedge-nettle (Stachys arvensis)
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
Mexican hedge-nettle (Stachys mexicana)
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
Rigid hedge-nettle (Stachys rigida)
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
Swamp hedge-nettle (Stachys pilosa)
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
California hedge-parsley (Yabea microcarpa)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Baja California, east to Idaho, Utah, and New Mexico.
Habitat: Along streams and vernally moist slopes at low elevations.
Origin: Native
Flowers: April-June
False hedge-parsley (Yabea microcarpa)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to Baja California, east to Idaho, Utah, and New Mexico.
Habitat: Along streams and vernally moist slopes at low elevations.
Origin: Native
Flowers: April-June
Field hedge-parsley (Torilis arvensis)
Distribution: Introduced in scattered locations in the Pacific Northwest, mostly west of the Cascades.
Habitat: Weed of disturbed ground.
Origin: Introduced
Flowers: July - September
Indian hedgemustard (Sisymbrium orientale)
Origin: Introduced
Rocky Mountain helianthella (Helianthella uniflora)
Distribution: Occurring east of the Cascades crest in Washington; British Columbia south to Oregon and Nevada, east to the Rocky Mountains.
Habitat: Dry, open woods at low to mid-elevations.
Origin: Native
Flowers: May-August
Garden heliotrope (Valeriana officinalis)
Origin: Introduced from Europe
Salt heliotrope (Heliotropium curassavicum)
Distribution: East of the Cascades in Washington; British Columbia south to tropical America.
Habitat: Saline places at low evelevations, often in the beds of dried ponds.
Origin: Native
Flowers: June-September
Seaside heliotrope (Heliotropium curassavicum)
Distribution: East of the Cascades in Washington; British Columbia south to tropical America.
Habitat: Saline places at low evelevations, often in the beds of dried ponds.
Origin: Native
Flowers: June-September
Siskiyou wild hellebore (Veratrum insolitum)
Distribution: Benton County, Oregon, south into northern California.
Habitat: Open prairies to thickets, and forested or open rocky slopes.
Origin: Native
Flowers: July - September
Broad-leaved helleborine (Epipactis helleborine)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to California, in scattered locations across central Canada and the U.S.; the Upper Midwest and Northeast U.S.
Habitat: Moist to dry, shady woods, disturbed sites.
Origin: Introduced from Eurasia
Flowers: June-October
Garden helleborine (Epipactis helleborine)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to California, in scattered locations across central Canada and the U.S.; the Upper Midwest and Northeast U.S.
Habitat: Moist to dry, shady woods, disturbed sites.
Origin: Introduced from Eurasia
Flowers: June-October
Giant helleborine (Epipactis gigantea)
Distribution: Occurring on both sides of the Cascades in Washington; British Columbia south to Baja California, east to the Rocky Mountains.
Habitat: Stream banks, lake margins, around springs and seeps, especially in thermal waters in otherwise desert regions.
Origin: Native
Flowers: April-July
Helleborine (Epipactis helleborine)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to California, in scattered locations across central Canada and the U.S.; the Upper Midwest and Northeast U.S.
Habitat: Moist to dry, shady woods, disturbed sites.
Origin: Introduced from Eurasia
Flowers: June-October
Hellroot (Orobanche minor)
Distribution: Occurring only sparingly, west of the Cascades in Washington; Washington south to Oregon; along the Atlantic Coast of the U.S.
Habitat: Lowland areas, parasitic, especially on clover.
Origin: Introduced
Flowers: May-June
Policeman's helmet (Impatiens glandulifera)
Distribution: Introduced in western Washington and British Columbia
Habitat: Escaped from cultivation at low elevations
Origin: Introduced from Asia
Flowers: July - September
Mountain hemlock (Tsuga mertensiana)
Distribution: Alaska to california, east to Montana; in both Olympics and Cascades in Washington
Habitat: Mid- to high elevations in the mountains
Origin: Native
Cones: June - July
Western hemlock (Tsuga heterophylla)
Distribution: Alaska to California, east to Montana, but much more common west of the Cascades
Habitat: Moist, deep forests from sea level to mid-elevations in the mountains
Origin: Native
Cones: May - June
Pacific hemlock-parsley (Conioselinum pacificum)
Distribution: West of the Cascades in Washington along the coast; Alaska and the Aleutian Islands, south to California.
Habitat: Bluffs and rocky or sandy beaches along the seashore.
Origin: Native
Flowers: July-August
Hemp (Cannabis sativa)
Distribution: Introduced in much of the United States
Habitat: Illegal plantings in openings in the forests
Origin: Introduced
Flowers: June - September
Indian hemp (Apocynum cannabinum)
Distribution: East of the Cascades in Washington; throughout much of North America.
Habitat: Uncommon in waste ground and lightly-cultivated areas, especially orchards.
Origin: Native
Flowers: June-September
Bifid hemp nettle (Galeopsis bifida)
Distribution: Known from Kittitas County in Washington; Alaska to Washington, east across north U.S. and Canada to Atlantic Coast.
Habitat: Disturbed areas, roadsides, and irrigation channels.
Origin: Introduced
Flowers: July-August
Common hemp nettle (Galeopsis tetrahit)
Distribution: Chiefly west of the Cascades in Washington; Alaska to Newfoundland, south to Central Plains and Mid-Atlantic states.
Habitat: Meadows and other moist places.
Origin: Introduced from Eurasia
Flowers: July-August
Fat hen (Atriplex prostrata)
Distribution: Occurring on both sides of the Cascades crest in Washington; Washington south 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
Spotted hen-nettle (Lamium maculatum)
Distribution: Chiefly west of the Cascades in Washington; Alaska, Oregon, Idaho; eastern North America.
Habitat: Disturbed ground.
Origin: Introduced from Eurasia
Flowers: April - August
Black henbane (Hyoscyamus niger)
Distribution: Scattered localities on both sides of the Cascades in Washington; widely distributed throughout uNorth America from Alberta to Nevada, east to central and northeastern North America.
Habitat: Roadsides and waste places.
Origin: Introduced from Europe
Flowers: May-August
Henbit (Lamium purpureum)
Distribution: Both sides of the Cascades in Washington, but more common on the west side; introduced throughout North America.
Habitat: Weed in distrurbed areas, fields, lawns at lower elevations.
Origin: Introduced from Eurasia
Flowers: April-July
Spotted henbit (Lamium maculatum)
Distribution: Chiefly west of the Cascades in Washington; Alaska, Oregon, Idaho; eastern North America.
Habitat: Disturbed ground.
Origin: Introduced from Eurasia
Flowers: April - August
Herb-bennet (Geum urbanum)
Distribution: In scattered locations on both sides of the Cascades crest in Washington; Washington south to Oregon and Utah; also occurring in northeastern U.S.
Habitat: Disturbed areas in including, roadsides, wastelots, and fields.
Origin: Introduced
Flowers: May-September
Herbrobert (Geranium robertianum)
Distribution: West of the Cascades in Washington; Alaska south to California, east to Montana; widely distributed in upper Midwest and eastern North America.
Habitat: Mostly in moist, disturbed ground
Origin: Introduced from Europe
Flowers: March-July
Highbush cranberry (Viburnum opulus)
Distribution: Scattered localities throughout Washington; British Columbia south to the Columbia River Gorge, east to Idaho and Montana.
Habitat: Moist woods at low to moderate elevations.
Origin: Native
Flowers: May-July
Hoary-aster (Dieteria canescens)
Distribution: East of the Cascades in Washington; southern British Columbia to southern California, east to Saskatchewan and Arizona.
Habitat: Dry, open places in the plains and foothills, occasionally extending into the mountains.
Origin: Native
Flowers: July-October
Chalapa hoarycress (Lepidium chalepense)
Distribution: Occurring east of the Cascades crest in Washington; widely distributed throughout much of North America.
Habitat: Disturbed areas, especially where dry, often associated with agriculture.
Origin: Introduced from Asia
Flowers: May-June
Globepodded hoarycress (Lepidium appelianum)
Distribution: Widely distributed throughout many areas in Washington, though more common east of the Cascades crest; widely distributed throughout much of North America.
Habitat: Disturbed soil, waste areas, in dry and moist places.
Origin: Introduced from Asia
Flowers: April-August
Heart-podded hoarycress (Lepidium draba)
Distribution: Occurring chiefly east of the Cascades crest in Washington; widely distributed throughout much of North America.
Habitat: Widespread weed in lowlands.
Origin: Introduced from Eurasia
Flowers: April-August
Lens-podded hoarycress (Lepidium chalepense)
Distribution: Occurring east of the Cascades crest in Washington; widely distributed throughout much of North America.
Habitat: Disturbed areas, especially where dry, often associated with agriculture.
Origin: Introduced from Asia
Flowers: May-June
Hogbite (Chondrilla juncea)
Distribution: Occurring chiefly east of the Cascades in Washington; British Columbia south to California and east to Montana; also occurring in eastern North America.
Habitat: Dry, light soil, rangeland and roadsides.
Origin: Introduced from Eurasia
Flowers: July-September
Giant hogweed (Heracleum mantegazzianum)
Distribution: Occurring west of the Cascades crest in Washington;
Habitat: Disturbed areas often associated with residential development.
Origin: Introduced
Flowers: June-July
English holly (Ilex aquifolium)
Distribution: Introduced west of the Cascades in Washington; British Columbia south to California; Ontario province.
Habitat: Spread by birds, mostly forested areas at low elevations.
Origin: Introduced from Europe
Flowers: April-June
Hollyhock (Alcea rosea)
Distribution: In a few scattered locations in Washington; widely distributed throughout much of North America.
Habitat: Garden escape establishing in disturbed areas.
Origin: Introduced
Flowers: May-August
Holy-clover (Onobrychis viciifolia)
Distribution: Occasionally introduced in scattered locations throughout Washington; ranging throughout western North America and parts of central and eastern North America.
Habitat: Waste ground, disturbed soil.
Origin: Introduced
Flowers: June-August
Honesty (Lunaria annua)
Distribution: Distributed in scattered locations across Washington; British Columbia south 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
Amur honeysuckle (Lonicera maackii)
Origin: Introduced
Bearberry honeysuckle (Lonicera involucrata)
Distribution: Both sides of the Cascades in Washington; Alaska south to California, east to Montana and New Mexico.
Habitat: Common in open woods at low to mid-elevations.
Origin: Native
Flowers: April-August
Bluefly honeysuckle (Lonicera cauriana)
Distribution: Reported from Washington; Alaska to California, also in Idaho.
Origin: Native
Etruscan honeysuckle (Lonicera etrusca)
Distribution: Occasional west of the Cascades in Washington; established along the Oregon coast and southern British Columbia.
Habitat: Thickets and waste areas.
Origin: Introduced
Flowers: June-August
European fly honeysuckle (Lonicera xylosteum)
Origin: Introduced
Hairy honeysuckle (Lonicera hispidula)
Distribution: West of the Cascades in Washington; British Columbia to Oregon.
Habitat: Open woods at low elevations.
Origin: Native
Flowers: June-August
Japanese honeysuckle (Lonicera japonica)
Distribution: Occasionally escaped from cultivation in lowland western Washington; California east through the midwestern, southeastern, and northeastern U.S.
Habitat: Disturbed areas, woods, and thickets.
Origin: Introduced
Flowers: May-July
Orange honeysuckle (Lonicera ciliosa)
Distribution: Ranging throughout Washington; British Columbia south to Oregon, east to Montana.
Habitat: Open to rather dense woods, low to mid-elevations in the mountains.
Origin: Native
Flowers: May-July
Purple-flower honeysuckle (Lonicera conjugialis)
Distribution: Mt. Adams south chiefly through the east side of the Cascades in Washington; south 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
Rocky Mountain honeysuckle (Lonicera utahensis)
Distribution: Both sides of the Cascades in Washington; British Columbia to Oregon, east to Montana and south in the Rockies to Arizona.
Habitat: Mid- to high elevations in the mountains.
Origin: Native
Flowers: May-July
Showy fly honeysuckle (Lonicera ×bella)
Origin: Introduced
Sweet-berry honeysuckle (Lonicera cauriana)
Distribution: Reported from Washington; Alaska to California, also in Idaho.
Origin: Native
Tartarian honeysuckle (Lonicera tatarica)
Distribution: Scattered localities throughout Washington; throughout much of North America except the southeastern U.S.
Habitat: Disturbed areas, woods, and thickets.
Origin: Introduced from Eurasia
Flowers: May-July
Utah honeysuckle (Lonicera utahensis)
Distribution: Both sides of the Cascades in Washington; British Columbia to Oregon, east to Montana and south in the Rockies to Arizona.
Habitat: Mid- to high elevations in the mountains.
Origin: Native
Flowers: May-July
Spiny hopsage (Grayia spinosa)
Distribution: Occurring east of the Cascades in Washington; Washington south to California, east to Colorado.
Habitat: Foothills and desert valleys, often in alkaline soil.
Origin: Native
Flowers: April-June
White horehound (Marrubium vulgare)
Distribution: Both sides of the Cascades in Washington; introduced in most of the United States.
Habitat: Weed of disturbed sites
Origin: Introduced from Eurasia
Flowers: June-October
Deer horn (Clarkia pulchella)
Distribution: Chiefly east of the Cascades in Washington; British Columbia to Oregon, east to South Dakota.
Habitat: Dry, open slopes, low to mid-elevations.
Origin: Native
Flowers: May-June
Spineless hornwort (Ceratophyllum echinatum)
Origin: Native
Horse-chestnut (Aesculus hippocastanum)
Distribution: West of the Cascades in Washington; British Columbia south to Oregon; 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
Flowers: May-June
Gray horsebrush (Tetradymia canescens)
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to California, east to Montana and New Mexico.
Habitat: Dry, open places in the foothills and plains.
Origin: Native
Flowers: June-September
Spineless horsebrush (Tetradymia canescens)
Distribution: Occurring east of the Cascades crest in Washington; southern British Columbia to California, east to Montana and New Mexico.
Habitat: Dry, open places in the foothills and plains.
Origin: Native
Flowers: June-September
Horseradish (Armoracia rusticana)
Distribution: Occurring in scattered locations in eastern portion of Washington; British Columbia south to California, east across the U.S. and Canada to the Atlantic Coast.
Habitat: Disturbed areas including fields, roadsides and wastelots.
Origin: Introduced from Eurasia
Flowers: May-July
Common horsetail (Equisetum arvense)
Distribution: Cosmopolitan; throughout the Pacific Northwest
Habitat: Moist to moderately dry areas
Origin: Native
Field horsetail (Equisetum arvense)
Distribution: Cosmopolitan; throughout the Pacific Northwest
Habitat: Moist to moderately dry areas
Origin: Native
Giant horsetail (Equisetum telmateia)
Distribution: British Columbia to California, east to Idaho
Habitat: Moist areas in the lowlands
Origin: Native
Marsh horsetail (Equisetum palustre)
Distribution: Circumboreal, south south in North America to southern Washington, northern Idaho, Nebraska and Pennsylvania.
Habitat: Streambanks, wet meadows, and marshes, from the lowlands to moderate elevations in the mountains.
Origin: Native
Meadow horsetail (Equisetum pratense)
Origin: Native
Nelson's horsetail (Equisetum ×nelsonii)
Origin: Native
Or river horsetail (Equisetum fluviatile)
Distribution: Alaska to Oregon, east across southern Canada and the northern tier of states in the United States.
Habitat: Shallow water, marshes and bogs, along muddy shores, from the lowlands to moderate elevations in the mountains.
Origin: Native
Scouringrush horsetail (Equisetum hyemale)
Distribution: Circumboreal; throughout the Pacific Northwest
Habitat: Moist to wet areas, lowlands to moderate elevations in the mountains
Origin: Native
Sedgelike horsetail (Equisetum scirpoides)
Distribution: Circumboreal, south in North America to northeast Washington, east to northwest Montana, Minnisota, and New York.
Habitat: Moist, swampy places, especially in coniferous forests.
Origin: Native
Shore horsetail (Equisetum ×litorale)
Origin: Native
Variegated horsetail (Equisetum variegatum)
Distribution: Alaska to Oregon, east across southern Canada and the northern third of the United States
Habitat: Wet places, sea level to alpine
Origin: Native
Wood horsetail (Equisetum sylvaticum)
Distribution: Alaska to Washington, east across southern Canada and northern United States to the Atlantic Coast
Habitat: Shady coniferous forests, bog edges and swamps
Origin: Native
Woodland horsetail (Equisetum sylvaticum)
Distribution: Alaska to Washington, east across southern Canada and northern United States to the Atlantic Coast
Habitat: Shady coniferous forests, bog edges and swamps
Origin: Native
Horseweed (Conyza canadensis)
Distribution: Common introduction throughout the United States and Canada
Habitat: Weed of roadsides, dry or moist disturbed ground
Origin: Native
Flowers: July - September
Water Howellwort (Howellia aquatilis)
Distribution: Chiefly west of the Cascades in Washington; Washington south to California, east to Idaho and Montana.
Habitat: In ponds and lakes.
Origin: Native
Flowers: May-July
Evergreen huckelberry (Vaccinium ovatum)
Distribution: Occurring west of the Cascades crest in Washington; British Columbia south to California.
Habitat: Coniferous forests at low elevations.
Origin: Native
Flowers: April-August
Blueleaf huckleberry (Vaccinium deliciosum)
Distribution: Ocurring in the Olympic and Cascade Mountains of Washington; British Columbia south to California, east to Idaho.
Habitat: Forest openings and mountain meadows, mid- to high elevations.
Origin: Native
Flowers: May-July
Dwarf huckleberry (Vaccinium cespitosum)
Distribution: Widely distributed in the mountainous areas of Washington; Alaska south to California, east to Colorado; across southern Canada and the northern tier of states from Minnesota to Maine.
Habitat: Moist rocky ridges and meadows, mid- to high elevations in the mountains.
Origin: Native
Flowers: May-July
Red huckleberry (Vaccinium parvifolium)
Distribution: Chiefly west of the Cascades in Washington; Alaska to California on both sides of the Cascades, but much more common on the west side
Habitat: Moist woods, sea level to mid-elevations in the mountains.
Origin: Native
Flowers: April-June
Tall huckleberry (Vaccinium membranaceum)
Distribution: Widely distributed throughout forested and mountainous areas of Washington; British Columbia south to California, east the Rocky Mountains; Ontario and Michigan.
Habitat: Common in dry to moist coniferous forests and open areas, moderate to mid-elevations in the mountains.
Origin: Native
Flowers: May-July
Thin-leaved huckleberry (Vaccinium membranaceum)
Distribution: Widely distributed throughout forested and mountainous areas of Washington; British Columbia south to California, east the Rocky Mountains; Ontario and Michigan.
Habitat: Common in dry to moist coniferous forests and open areas, moderate to mid-elevations in the mountains.
Origin: Native
Flowers: May-July
Dwarf hulsea (Hulsea nana)
Distribution: Known from the Mt. Rainier and Mt. Adams area in Washington; Washington south to California.
Habitat: Generally around volcanic mountains above timberline.
Origin: Native
Flowers: July-September
Hungerweed (Ranunculus arvensis)
Distribution: Known only from along eastern border in Washington; Washington south 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
Hutchinsia (Hornungia procumbens)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains, central Canada, and Newfoundland.
Habitat: Open areas where seasonally moist.
Origin: Native?
Flowers: March-June
Prostrate hutchinsia (Hornungia procumbens)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains, central Canada, and Newfoundland.
Habitat: Open areas where seasonally moist.
Origin: Native?
Flowers: March-June
Water hyacinth (Eichhornia crassipes)
Distribution: Known from a few localities in southern Washington; California east along the southern part of the U.S. to Florida.
Habitat: Ponds, ditches, canals.
Origin: Introduced from tropical America
Flowers: April-September
Wild hyacinth (Triteleia hyacinthina)
Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia south to Oregon, east to Idaho.
Habitat: Sagebrush deserts and grassy, often rocky areas from low to mid-elevations in the mountains.
Origin: Native
Flowers: May-August
Hydrilla (Hydrilla verticillata)
Origin: Introduced from Eurasia
Fineleaf hymenopappus (Hymenopappus filifolius)
Distribution: Occurring east of the Cascades crest in Washington; Washington south to California, east to the Great Plains of Canada and the U.S.
Habitat: Dry, often sandy places in the foothills and plains.
Origin: Native
Flowers: May-July
Wild hyssop (Verbena hastata)
Distribution: Chiefly east of the Cascades in Washington; widely distributed throughout North America.
Habitat: Marshes, wetlands, streamsides, and other riparian areas.
Origin: Native
Flowers: July-September