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Northern Prairie Wildlife Research Center

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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

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