Page author: Don Knoke
Cyperus lupulinus
Great Plains flatsedge

Distribution: Great Plains to northeastern United States; occasional in the Pacific Northwest.

Habitat: Wet areas.

Flowers: June - August

Origin: Native

Conservation Status: Review Group 1 in Washington (WANHP)


Herbaceous, tufted perennial from a crown, with knotted rhizomes, the culms triangular, glabrous, 10-50 cm. tall and 0.4-1.2 mm. broad.


Leaves flat, 5-40 cm. long and 1-3.5 mm. broad; sheaths closed.


Inflorescence an ovoid to globose cluster of spikes, 1.2-3.5 cm. in diameter, the rays of the spikes 1-4, 1-6 cm. long; spikelets 15-60, compressed, oblong-lanceolate, 6-22 mm. by 2.5-4 mm.; scales 5-22, off-white to light reddish-brown, ovate-elliptic, 2.5-4 by 2-2.6 mm.; perianth none; stigmas 3; styles trifid.


Achenes dark brown to black, sessile, ellipsoid, about 2 mm. long and 1 mm. wide.

Accepted Name:
Cyperus lupulinus (Spreng.) Marcks
Publication: Trans. Wisconsin Acad. Sci. 62: 271. 1974.

Synonyms & Misapplications:
Scirpus lupulinus Spreng.
ssp. lupulinus – Great Plains flatsedge
Additional Resources:

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

WA Flora Checklist: Cyperus lupulinus checklist entry.

E-Flora BC: Cyperus lupulinus atlas page.

CalPhotos: Cyperus lupulinus photos.

USDA Plants: Cyperus lupulinus information.

7 photographs:
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