Distribution: Ocurring chiefly west of the Cascades crest in Washington; southwestern British Columbia to California, east to Idaho and Montana; native from central North America to the Atlantic Coast.
Habitat: Wet areas and riparian zones at low elevations.
Flowers: July-August
Origin: Introduced from eastern North America
Growth Duration: Perennial
Conservation Status: Not of concern
Pollination: Wind
Herbaceous perennial, without rhizomes, the culms 8-15 dm. tall, sub-terete.
Stems leafy, the leaves grass-like, elongate, flat, 2-6 mm. wide.
Inflorescence a compound, terminal cyme, with very numerous spikes 3-8 mm. long on short, slender peduncles; inflorescence subtended by several unequal, blackish-based, sheathless bracts, the largest of them nearly 1 dm. long; flowers subtended by blunt scales 1.5 mm. long, with fine red-brown lines on a pale or blackish-green background; perianth of 6 tawny, flexuous bristles that surpass the scales; stamens 3; style trifid.
Achenes triangular, pale, under 1 mm. long.
PNW Herbaria: Specimen records of Scirpus cyperinus in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Scirpus cyperinus checklist entry
OregonFlora: Scirpus cyperinus information
E-Flora BC: Scirpus cyperinus atlas page
CalPhotos: Scirpus cyperinus photos