Vascular Plants

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


Browse by scientific name:

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Scientific names beginning with I:
13 genera
35 species, 4 subspecies and varieties
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Idahoa scapigeraflatpod, scalepod
Distribution: East of the Cascades in Washington; Washington sout to California, east to Idaho.
Habitat: Shrub-steppe, especially with sagebrush.
Origin: Native
Flowers: March-April
Ilex aquifoliumEnglish holly
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
Iliamna longisepalalong-sepal globemallow
Distribution: Occurring east of the Cascades crest in Washington, where endemic to Chelan and Douglas counties.
Habitat: From sagebrush desert to ponderosa pine forest openings at low elevations.
Origin: Native
Flowers: June-August
Iliamna rivularisstreambank globemallow
Distribution: Occurring east of the Cascades crest in Washington; British Columbia to Oregon, east to Montana and Colorado.
Habitat: Somewhat moist areas, often along seasonal stream banks, foothills to forest openings at mid-elevations.
Origin: Native
Flowers: June-August
Impatiens aurellavaried jewelweed
Distribution: Extreme southeast Washington and northern Idaho to southeast British Columbia and western Montana.
Habitat: Moist woods.
Origin: Native
Flowers: July - September
Impatiens capensisspotted jewelweed
Distribution: Occurring chiefly west of the Cascades crest in Washington; widely distributed throughout much of North America.
Habitat: Moist woods, lake, pond, and stream edges, and other wetland areas at low elevations.
Origin: Introduced; not native west of the Rocky Mountains
Flowers: July-October
Impatiens ecornutaspurless jewelweed
Distribution: Occurring on both sides of the Cascades in Washington; southern British Columbia to northwest Oregon, east to Montana.
Habitat: Moist, shady woods.
Origin: Native
Flowers: August-September
Impatiens glanduliferapoliceman's helmet
Distribution: Introduced in western Washington and British Columbia
Habitat: Escaped from cultivation at low elevations
Origin: Introduced from Asia
Flowers: July - September
Impatiens noli-tangereboreal jewelweed, or western touch-me-not
Distribution: Alaska to Oregon, from the coast inland to Idaho.
Habitat: Moist woods.
Origin: Native
Flowers: July - September
Impatiens ×pacificaPacific jewelweed
Distribution: Occurring in lowlands west of the Cascades in Washington; Washington south to Oregon.
Habitat: Wet areas including wetlands, sloughs, forest edges, and disturbed areas.
Origin: Native
Flowers: August-October
Impatiens parviflorasmall-flowered jewelweed, small-flowered touch-me-not
Distribution: Currently (2016) known in Washington from King County (only); southwestern British Columbia, western Washington and northwestern Oregon; also occurring in eastern North America.
Habitat: Disturbed forest edge and understory at low elevations, often where at least seasonally moist.
Origin: Introduced
Flowers: June-July
Inula heleniumelecampane, inula
Distribution: Known in Washington from a single location east of the Cascades crest in Washington; British Columbia to California, also in central and eastern North America.
Habitat: Roadsides, fields, wastelots, and other disturbed open areas at low elevations.
Origin: Introduced from Asia
Flowers: June-September
Ionactis stenomeresRocky Mountain ankle-aster, Rocky Mountain aster
Distribution: Southeast British Columbia and northeast Washington, and adjacent Idaho and Montana.
Habitat: Open hillsides and forest openings, moderate to fairly high elevations in the mountains.
Origin: Native
Flowers: Late June - Early September
Ipomopsis aggregatascarlet gilia, skyrocket
Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains, Oklahoma and Texas.
Habitat: Open or lightly wooded, drier meadows and rocky slopes, lowlands to fairly high elevations in the mountains.
Origin: Native
Flowers: May-August
ssp. aggregata – scarlet gilia, skyrocket
Ipomopsis congestaballhead gilia, many-flowered gilia
Distribution: Occurring on the eastern border of Washington; Washington south to California, east to the Great Plains.
Habitat: Dry, open areas at low to middle elevations.
Origin: Native
Flowers: June-July
ssp. congesta – ballhead gilia, many-flowered gilia
Iris foetidissimastinking iris
Origin: Introduced from Europe
Iris germanicabearded iris, German iris
Origin: Introduced from southern Europe
Iris missouriensiswestern blue flag, Rocky Mountain iris
Distribution: Occurring chiefly east of the Cascades crest in Wahington, but also known from the Puget Sound area; British Columbia to California, east to the Rocky Mountains.
Habitat: Common in vernally moist meadows, especially in sagebrush and Ponderosa pine forests.
Origin: Native
Flowers: May-July
Iris pseudacoruspale yellow iris
Distribution: Occurring on both sides of the Cascades crest in Washington, but more common west of the crest; British Columbia to California, east to Idaho and Montana; also in eastern North America.
Habitat: Wetlands, lake and pond margins, irrigation ditches, backwaters, and other wet places where often disturbed; invasive.
Origin: Introduced from Eurasia
Flowers: May-July
Iris sibiricaSiberian iris
Origin: Introduced
Iris tenaxOregon flag, tough-leaf iris
Distribution: Occurring west of the Cascades crest in Washington; Washington to California.
Habitat: Prairies, meadows, open oak and coniferous forests, at low to middle elevations.
Origin: Native
Flowers: April-June
var. tenax – Oregon flag, tough-leaf iris
Isatis tinctoriaDyer's woad
Distribution: Known only from scattered locations in central Washington; British Columbia south to California, east to the Rocky Mountains; also occurring in parts of central and eastern North America.
Habitat: Disturbed dry ground, pastures, and roadsides, where often escaped from cultivation.
Origin: Introduced from Eurasia
Flowers: April-June
Isoetes bolanderiBolander's quillwort
Origin: Native
Isoetes howelliiHowell's quillwort
Origin: Native
Isoetes maritimamaritime quillwort
Origin: Native
Isoetes minimamidget quillwort
Distribution: Currently known only from Kittitas and Spokane Counties in Washington, and in south-central British Columbia.
Habitat: Seasonally moist swales and vernal pools at middle elevations among open conifer forest or sagebrush-steppe.
Origin: Native
Spores: June
Isoetes nuttalliiNuttall
Origin: Native
Isoetes occidentaliswestern quillwort
Distribution: Occurring chiefly west of the Cascades crest; Alaska to California, east to the Rocky Mountains.
Habitat: Submerged in ponds and lakes, often in deep water, from the lowland to middle elevations in the mountains.
Origin: Native
Isoetes tenellabristle-like quillwort, spiny spored quillwort
Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, also eastward to the Great Lakes region and northeastern North America; circumboreal.
Habitat: In shallow water or along shorelines of ponds and lakes, from the lowlands to middle elevations in the mountains.
Origin: Native
Isoetes ×truncata
Origin: Native
Isolepis cernualow clubrush, low lateral clubrush
Distribution: Coastal from Southern British Columbia south to northern Mexico.
Habitat: Usually in brackish to saline water of marshes, beaches, and shores.
Origin: Native
Flowers: June - August
Isolepis setaceaEurasian bulrush, bristle-leaf sedge
Origin: Introduced
Iva axillarisdeeproot, deer root, poverty weed
Distribution: Chiefly east of the Castades, southern British Columbia to California, east to Manitoba and Oklahoma.
Habitat: Dry, often alkaline places, in the valleys, plains and foothills.
Origin: Native
Flowers: May - September
Ivesia gordoniigordon's ivesia, alpine mousetail
Distribution: Mt. Adams, Wenatchee and Blue Mountains in Washington; Blue and Wallowa Mountains in Oregon; Montana to Colorado in the Rockies, west to California
Habitat: Floodplains and riverbanks to alpine ridges and talus
Origin: Native
Flowers: Late June - August
Ivesia tweedyiTweedy's mousetail
Distribution: East of the Cascades crest in Washington; Washington east to Idaho and Montana.
Habitat: Dry, open to wooded areas, mid- to high elevations in the mountains.
Origin: Native
Flowers: June-August