USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Aquatic and Wetland Vascular Plants of the Northern Great Plains

62. Cyperaceae, the Sedge Family

11. Scirpus L. -- Bulrush

2. Scirpus cyperinus (L.) Kunth. -- Wool grass

Coarse, tufted perennial from short rhizomes; culms obtusely trigonous, to 2 m tall. Leaves numerous on the culms; blades 3-10 mm wide, scabrous on the margins, involute toward the tips; sheaths brownish, dark brown at the mouth; involucral bracts usually 2-4, foliaceous, spreading, the longest shorter than to surpassing the inflorescence, usually brown or reddish-brown at the base. Inflorescence large and spreading, with several to many slender primary branches or rays to 15 cm long, these bearing a secondary set of reduced involucral bracts and branches at their summit, the secondary branches themselves often terminating in a tertiary set of involucral bracts and branches, the ultimate branches spreading to drooping, terminating in glomerules of 2-several spikelets, or some spikelets borne singly, sometimes mostly single; spikelets very numerous, ovoid, 3-6 mm long, 2-3 mm wide, appearing woolly due to the long perianth bristles; scales streaked with reddish-brown, sometimes blackish, elliptic-ovate, 1-1.3 mm long, bluntly-acute; perianth bristles 6, smooth, contorted, brownish, much exceeding the scale; styles trifid. Achenes whitish to tan, flattened-trigonous, the dorsal angle low, 0.6-0.9 mm long, ca. 1/2 as wide, with a short, slender beak. Jul--Sep. Wet meadows, marshes and swamps; rare, with records from Custer and Pennington counties, SD; also w MN and IA; (Newf. to s B.C., s to FL, e TX and SD). S. atrocinctus Fern.
GIF- Distribution Map

Map key

Previous Section -- Scirpus acutus Muhl. ex Bigel. -- Hardstem bulrush
Return to Family -- Cyperaceae - The Sedge Family
Next Section -- Scirpus fluviatilis (Torr.) A. Gray -- River bulrush

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 06:47:00 EST
Sioux Falls, SD [sdww55]