Culms 10-90(-135) cm. Leaves 3-6 per culm; sheaths tight, inner band hyaline, 1.8-2.5 cm, apex concave, glabrous; ligules 0.6-2.5(-4.5) mm, rounded to ± acute; blades plicate, 5-40 cm × 0.7-3.3(-3.8) mm, widest leaf 1-3.3(-3.8) mm wide. Inflorescences 0.7-7.8 cm; spikes (2-)3-8; lateral spikes pistillate often with few staminate flowers proximally, 3-15.5 mm, sessile, staminate portion 7-flowered, to 8.2 mm, pistillate portion 3-32-flowered, 2.5-11 mm; basal 2 spikes 1.7-42 mm apart; terminal spike gynecandrous, 5-24 mm, staminate portion 2-17-flowered, 2-16.5 × 0.9-2 mm, pistillate portion 4-26-flowered, 2.6-9 × 4.9-9.1 mm. Pistillate scales ovate, (1.4-)2.1-3.1 × 0.7-2.3 mm, apex acute to sometimes obtuse. Staminate scales ovate-lanceolate to ovate, 1.3-3.8 × 0.8-1.7 mm, base clavate, apex acute. Anthers 0.8-1.6(-2) mm. Perigynia spreading to reflexed, castaneous to dark brown, 2-14-veined abaxially, 0-12-veined adaxially over achene, lanceolate to ovate, (2.65-)2.9-4.75 × 0.8-2.1 mm, (1.7-)1.8-3.2(-3.6) times as long as wide; beak (0.85-)0.95-2 mm, (0.4-)0.45-0.86 length of body, serrulate, teeth (0-)0.15-0.5 mm. Achenes ovate-lanceolate to rhombic-ovate, 1.3-2.1 × 0.8-1.55 mm. 2n = 58.