Herbs, perennial, rhizomatous, coarse. Culms trigonous, 50-150 cm × 2-15 mm, glabrous (rarely sparsely scabridulous on angles proximal to bracts). Leaves inversely W-shaped, 40-100 cm × 5-15 mm. Inflorescences: spikes 1-4, cylindric, (2.5-)3.5-5 × 1.2-1.5 cm; rays 8-10, (1-)15-35 cm; 2d order rays 1-3 cm; bracts 8-12, ascending at 45-60°, (5-)20-80 cm × 3-15 mm; 2d order bracts 3-7 cm × 2-4 mm; rachilla persistent, wings 0.3 mm wide, at achene maturation adaxial edge of wing detaching from rachilla, base remaining firmly attached. Spikelets 35-65, slightly compressed, linear, ± quadrangular, 5-8 × 0.8-1.1 mm; floral scales deciduous, 12-16, appressed, marginally clear, laterally reddish along midrib, medially green, laterally 1-2-ribbed, medially strongly 5-ribbed, ovate, 1.6-1.8 × 1.1-1.3 mm, apex mucronulate. Flowers: anthers 0.4-0.5 mm, connective blunt, at most 0.1 mm; styles 0.8-1 mm; stigmas 0.4 mm. Achenes brown or whitish, sessile, ellipsoid, slightly wider at base, 0.9 × 0.4 mm, surfaces finely puncticulate.

Fruiting summer. Wet pastures, stream banks; 0-100 m; Fla., Tex.; Mexico; Central America; South America; Asia; Africa.