Cyperus strigosus - Strawcolor Flatsedge; False Nutsedge

General Species Description

Cyperus Strigosus is a stout perennial sedge distinguished by its slender-pointed, straw-colored spikelets with pointed scales. Flower spikes are clumped within 3 or more long leafy involucral bracts. Cyperus Strigosus has a erect triangular stem and grows up to 3 feet tall from a thick nonrhizomatous almost bulb-like root base.

Leaves

Leaves are long, narrow, somewhat rough along the edges, up to 1/3 inch broad, and crowded at base of stem. Leaves have closed sheaths.

Inflorescence/Flowers

5-12 flower stems (.5-4cm long) produce a greenish-yellow spike flower. Flower spikelets are narrowed to a slender point (up to 1 inch long) and emerge in dense cylinderic clusters perpendicular to the flower stem.

Fruits

Achene lens-shaped or 3-angled, reddish, 1/20-1/10 inch long.

Habitat

Moist fallow fields, wet prairies, along streams, around ponds and lakes at lower elevations.

Range

Widespread in Canada and the United States. Uncommon in Washington but grows frequently in Southern Oregon.

Similar Species

Potentially confused with the smaller Cyperus Aristatus found in similar habitats. In addition to its smaller size (6 inches) Cyperus Aristatus usually has more erect involucral bracts. Also potentially mistaken for Scirpus Microcarpus from a distance.

Ecological Value

Abundant Achenes provide forage for wildlife.

Human Value

None known

References

Cooke, S. S., ed. 1997. A Field Guide to the Common Wetland Plants of Western Washington & Northwest Oregon. Seattle Audubon Society and Washington Native Plant Society. Seattle Audubon Society, Seattle WA, 288pp.

Hitchcock, C. L. and A. Cronquist. 1973. Flora of the Pacific Northwest. University of Washington Press, Seattle WA, 596pp.

Knobel, Edward. 1980. Field Guide to the Grasses, Sedges, and Rushes of the United States. Dover Publications, New York, 53-54pp.

Northern Prairie Wildlife Research Center, 1999. Midwestern Wetland Flora, USGS, published online at:

http://www.npwrc.usgs.gov/resource/othrdata/plntguid/species/cypestri.htm

USDA Soil Conservation Service. 1993 Western Wetland Flora. Portland, OR, Group 3, Sedges.

This page was created by: Jim Labbe, August 1998

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