Page authors: Don Knoke, David Giblin
Cyperus bipartitus
shining flatsedge

Distribution: Occurring on both sides of the Cascades crest in Washington; widespread in North America.

Habitat: Streambanks and other wet places in the valleys and lowlands; tolerant of alkali.

Flowers: June-August

Origin: Native

Growth Duration: Annual

Conservation Status: Not of concern


Tufted annual, the triangular, solid, slender stems 0.5-2 dm. tall.


Leaves few, grass-like, all attached near the base, slender and elongate, 0.5-2 mm. wide, the sheaths closed.


Inflorescence of spikelets in 1-several capitate clusters, the primary cluster sessile, the others on slender rays up to 3 cm. long in the axils of sheathless, leafy, unequal involucral bracts, at least one surpassing the inflorescence; spikelets 3-15 mm. long; scales of the spikelets in 2 vertical rows, 2-2.5 mm. long, blunt, with a pale mid-rib; perianth none; stamens usually 2; style deeply bifid.


Achenes lenticular, 1.0-1.3 mm. long, olivaceous to blackish.

Accepted Name:
Cyperus bipartitus Torr.
Publication: Ann. Lyceum Nat. Hist. New York. 3: 257. 1836. 1836.

Synonyms & Misapplications:
Cyperus niger Ruiz & Pav. var. rivularis (Kunth) V.E. Grant
Cyperus rivularis Kunth [HC]
Additional Resources:

PNW Herbaria: Specimen records of Cyperus bipartitus in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Cyperus bipartitus checklist entry.

E-Flora BC: Cyperus bipartitus atlas page.

CalPhotos: Cyperus bipartitus photos.

USDA Plants: Cyperus bipartitus information.

8 photographs:
Group by