Burke: Eriophorum chamissonis vs. Eriophorum viridicarinatum

	Eriophorum chamissonis	Eriophorum viridicarinatum
	Chamisso's cotton-grass, russet cottongrass	tassel cottongrass
Habit	Herbaceous perennial from extensive creeping rhizomes, the culms stout, 3-7 dm. tall.
Leaves	Leaves few, mostly basal, with well-developed sheath and narrow, channeled blade up to 2 mm. wide; sheathes closed; uppermost sheath about mid-culm, often bladeless.
Flowers	Spikelet terminal and solitary, with up to 7 sterile scales, the outermost enlarged, up to 2 cm. long; fertile scales subtending the flowers partly blackish-green, with the tip and margins paler, russet-flecked on a whitish background; perianth consisting of numerous capillary bristles 2-4 cm. long, reddish to white; stamens 3; style trifid.
Fruits	Achenes dark, about 2 mm. long, obovate.

	Eriophorum chamissonis	Eriophorum viridicarinatum
Flowering time	May-August	May-July
Habitat	Swamps and other wet places from along the coast to middle elevations in the mountains.	Cold swamps and peatlands in the mountains.
Distribution	Occurring west of the Cascades crest and in the northeastern corner of Washington; Alaska to Oregon, east to the Rocky Mountains, northern Great Plains, and Great Lakes region. [WildflowerSearch map] [BONAP county map]	Occurring east of the Cascades crest in northeastern Washington; Alaska to northeastern Washington, Idaho, western Montana, Wyoming, and Colorado, east across the northern Great Plains to the Great Lakes, and northeastern North America. [WildflowerSearch map] [BONAP county map]
Origin	Native	Native
Conservation status	Not of concern	Sensitive in Washington (WANHP)
Sibling taxa	E. angustifolium, E. gracile, E. virginicum, E. viridicarinatum	E. angustifolium, E. chamissonis, E. gracile, E. virginicum
Web links	Local floras: BC, OR, WA Local Web sites: Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Eriophorum viridicarinatum

Chamisso's cotton-grass, russet cottongrass

tassel cottongrass

Habit

Herbaceous perennial from extensive creeping rhizomes, the culms stout, 3-7 dm. tall.

Leaves

Leaves few, mostly basal, with well-developed sheath and narrow, channeled blade up to 2 mm. wide; sheathes closed; uppermost sheath about mid-culm, often bladeless.

Flowers

Spikelet terminal and solitary, with up to 7 sterile scales, the outermost enlarged, up to 2 cm. long; fertile scales subtending the flowers partly blackish-green, with the tip and margins paler, russet-flecked on a whitish background;

perianth consisting of numerous capillary bristles 2-4 cm. long, reddish to white;

stamens 3;

style trifid.

Fruits

Achenes dark, about 2 mm. long, obovate.

Eriophorum chamissonis

Eriophorum viridicarinatum

Flowering time

May-August

May-July

Habitat

Swamps and other wet places from along the coast to middle elevations in the mountains.

Cold swamps and peatlands in the mountains.

Distribution

Occurring west of the Cascades crest and in the northeastern corner of Washington; Alaska to Oregon, east to the Rocky Mountains, northern Great Plains, and Great Lakes region.

[WildflowerSearch map]

[BONAP county map]

Occurring east of the Cascades crest in northeastern Washington; Alaska to northeastern Washington, Idaho, western Montana, Wyoming, and Colorado, east across the northern Great Plains to the Great Lakes, and northeastern North America.

[WildflowerSearch map]

[BONAP county map]

Origin

Native

Conservation status

Not of concern

Sensitive in Washington (WANHP)

Sibling taxa

E. angustifolium, E. gracile, E. virginicum, E. viridicarinatum

E. angustifolium, E. chamissonis, E. gracile, E. virginicum

Web links