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: Marshes and other wet places, from sea level to moderate elevations in the mountains.

Flowers: June-September

Origin: Native

Growth Duration: Annual

Conservation Status: Not of concern

Pollination: Wind

Tufted annual, 0.5-5 dm. tall, the culms 0.5-2 mm. thick, with many ribs.

Leaves all basal and reduced to sheaths.

Spikelet terminal and solitary, 5-13 mm. long, ovoid, many-flowered, usually over 40; scales spirally arranged, 1.7-2.5 mm. long, purplish or brownish, with greenish mid-strip and paler, translucent margins, the lowest one sometimes empty; perianth bristles 6-7, brownish, about equal to the achene, or wanting; stamens 3; style usually bifid, thickened at the base.

Achenes lenticular, 1.0-1.5 mm. long, including the flattened tubercle, which is appressed to the summit of the brown, smooth and shining body of the achene.