Dulichium arundinaceum
three-way sedge

Distribution: Chiefly west of the Cascades in Washington, but also in Chelan, Yakima and Pend Oreille counties; British Columbia south to California, east to Idaho, Montana and to the eastern half of North America.

Habitat: Wet meadows, marshes, and shores of ponds and lakes.

Flowers: July-September

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern


Annual, perennial herb, up to 1 m, rhizomes long; stems not triangular but cylindric, hollow.


Cauline, 3-ranked, proximal bladeless; blade up to 15 cm x 3-8 mm, flat; sheath not splitting, parallel venation, green.


Spikes number 1-17, from sheaths of bladed leaves, 6-30 cm; spikelets generally arranged in head, spike, raceme, or panicle-like inflorescences, spikelets number 3-10, 1.5-3 cm x 1.2-2.5 mm, flat; bracts 2-ranked, numbering 4-8, 3-9.5 mm long, lanceolate-linear, veined, each with 1 flower in axil; flowers bisexual; perianth bristles number 6-9, approximately 5mm; stamens 3, anthers attached at base; style 2-branched, base persistent.


2-4 mm long, ellipsoid-linear, flat, yellow.

Accepted Name:
Dulichium arundinaceum (L.) Britton
Publication: Bull. Torrey Bot. Club. 21: 29. 1894.

Synonyms & Misapplications:
Cyperus arundinaceus L.
Dulichium arundinaceum (L.) Britton var. arundinaceum [FNA23]
Dulichium arundinaceum (L.) Britton var. boreale Lepage [FNA23]
Additional Resources:

PNW Herbaria: Specimen records of Dulichium arundinaceum in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Dulichium arundinaceum checklist entry.

E-Flora BC: Dulichium arundinaceum atlas page.

CalPhotos: Dulichium arundinaceum photos.

USDA Plants: Dulichium arundinaceum information.

33 photographs:
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