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.