Herbs, perennial, rhizomatous. Culms trigonous, 50-100 cm × 2.5-3 mm, glabrous. Leaves V-shaped, 20-50 cm × 4-7 mm. Inflorescences: spikes loosely ovoid, 1.5-7 cm wide; rays 5-13, 1-21 cm; 2d order rays 0.5-3 cm; bracts 3-8, V-shaped, 5-50 cm × 2.5-5.6 mm; rachilla persistent, wings 0.4-0.6 mm wide. Spikelets 5-30, compressed, linear, (5-)12-40 × 1.5-2.2 mm; floral scales deciduous, 6-24, reddish brown to yellowish brown laterally, greenish medially, 5-7-ribbed, elliptic, 3-4 × 1.4-1.6 mm, apex obtuse. Flowers: anthers 1.5-2 mm; styles 2-2.3 mm; stigmas 2-3 mm. Achenes dark brown, sessile, oblong, 1.5 × 0.4-0.5 mm, apex apiculate, surfaces puncticulate. Fruiting summer. Ditches, croplands; 100-1000 m; Kans., Mo., N.Mex., Okla., Tex.