Vascular Plants
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Common names beginning with H:
H&C] (Phlox longifolia)
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains.
Habitat: Dry, open, rocky places, from the lowlands to moderate or occasionally high elevations in the mountains.
Origin: Native
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
Puzzling halimolobos (Sandbergia perplexa)
Distribution: Known from Douglas County in Washington; Washington east toIdaho and Montana.
Habitat: Sagebrush desert, typically on lithosol.
Origin: Native
Halogeton (Halogeton glomeratus)
Origin: Introduced from Eurasia
Hardheads (Acroptilon 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
Hardheads (Centaurea nigra)
Distribution: Introduced in the Pacific Northwest and northeastern United States
Habitat: Uncommon weed in disturbed soil
Origin: Introduced from Europe
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
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
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: Native
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
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
Rough hawkbit (Leontodon hirtus)
Origin: Introduced
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
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
Bristly hawksbeard (Crepis setosa)
Distribution: West of the Cascades in Washington, south to California
Habitat: Disturbed areas at low elevation
Origin: Introduced
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
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
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
Low hawksbeard (Crepis nana)
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
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
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
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
Rough hawksbeard (Crepis setosa)
Distribution: West of the Cascades in Washington, south to California
Habitat: Disturbed areas at low elevation
Origin: Introduced
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
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
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
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
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
Common hawkweed (Hieracium lachenalii)
Distribution: Uncommon introduction west of the Cascades in Washington and Oregon
Habitat: Disturbed areas
Origin: Introduced from Europe
Common hawkweed (Hieracium vulgatum)
Origin: Introduced from Europe
English hawkweed (Hieracium lachenalii)
Distribution: Uncommon introduction west of the Cascades in Washington and Oregon
Habitat: Disturbed areas
Origin: Introduced from Europe
European hawkweed (Hieracium lachenalii)
Distribution: Uncommon introduction west of the Cascades in Washington and Oregon
Habitat: Disturbed areas
Origin: Introduced from Europe
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
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
Long bearded hawkweed (Hieracium longiberbe)
Distribution: Columbia River Gorge, Washington and Oregon.
Habitat: Hillsides and rock crevices.
Origin: Native
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Phipps\\\' hawthorn (Crataegus phippsii)
Origin: Native
Piper's 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
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
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
Western large-thorned hawthorn (Crataegus macracantha)
Origin: Native
Woodland hawthorn (Crataegus laevigata)
Origin: Introduced from northern Europe
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
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
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
Common heath-grass (Danthonia decumbens)
Origin: Introduced from Europe
Mountain heath-grass (Danthonia decumbens)
Origin: Introduced from Europe
Alpine heather (Harrimanella stelleriana)
Distribution: Alaska to the high Cascades of Washington
Habitat: Rocky slopes and seeps, alpine to subalpine
Origin: Native
Ground pine heather (Cassiope lycopodioides)
Distribution: Occurring west of the Cascades crest in Washington; Alaska south to Washington.
Habitat: Alpine rocky slopes and crevices.
Origin: Native
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Policeman's helmet (Impatiens glandulifera)
Distribution: Introduced in western Washington and British Columbia
Habitat: Escaped from cultivation at low elevations
Origin: Introduced from Asia
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
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
Hemp (Cannabis sativa)
Distribution: Introduced in much of the United States
Habitat: Illegal plantings in openings in the forests
Origin: Introduced
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
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
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
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
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
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?
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
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
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
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
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
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
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
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
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
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
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
Giant hogweed (Heracleum mantegazzianum)
Distribution: Occurring west of the Cascades crest in Washington;
Habitat: Disturbed areas often associated with residential development.
Origin: Introduced
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
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
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
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 SE Europe
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
Hairy honeysuckle (Lonicera hispidula)
Distribution: West of the Cascades in Washington; British Columbia to Oregon.
Habitat: Open woods at low elevations.
Origin: Native
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Dwarf huckleberry (Vaccinium caespitosum)
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
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
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
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
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
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
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: Introduced
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: Introduced
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
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
Hydrilla (Hydrilla verticillata)
Origin: Introduced from Eurasia
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