Plants densely cespitose, to 200 culms together; rhizomes may appear elongate in old clumps. Culms 45-90 cm; vegetative culms few, inconspiculous, usually fewer than 12 leaves, not strikingly 3-ranked. Leaves: sheaths glabrous, individually indistinct Y-shaped hyaline band reaching 0-8 mm below the collar, summit U-shaped or truncate, extending 0-2 mm beyond collar, smooth; distal ligules 2-4 mm; blades 3-6 per fertile culm, 2.5-25 cm × 1.8-3.2(-4) mm. Inflorescences open to congested, erect to nodding, pale or golden brown, 2-4.5 cm × 7.5-19 mm; proximal internode 3.5-12 mm; 2d internode 3-10 mm; proximal bracts scalelike or often with bristle tips shorter than or equaling inflorescences. Spikes 3-8, distant, distinct, globose to ovoid or conic, 8-14 × 4.5-9.5 mm, base rounded to acute, apex acute, obtuse, or rounded. Pistillate scales pale yellowish brown or occasionally copper-brown tinged, with narrow yellow-brown midstripe, lanceolate or lance-ovate, 3.7-4.4 mm, reaching base to middle of perignyium beaks, margin whitish to brownish hyaline, apex membranaceous, curled, acuminate or awned to 0.7 mm. Staminate scales acuminate-awned. Anthers (1.8-)2.2-3.6 mm. Perigynia 15-80 on larger spikes, loosely ascending, light green, yellow-brown, or copper-brown, green or brown winged, inconspicuously 0-3(-5)-veined adaxially, 0-8-veined abaxially, 1-2 veins in winged margin, broadly elliptic to ovate, flat or concavo-convex except over achene, (4.2-)4.6-6.7(-7.1 in larger perigynia) × 2.5-4 mm, 0.5-0.7 mm thick, herbaceous, ± opaque, with achene not visible through adaxial face, margin flat, including wing 0.6-1.1 mm wide smooth; beak tip, strongly flattened, 2-2.8 mm, serrulate-margined to apex, abaxial suture pale or copper-brown, distance from beak tip to achene 2.6-4.2 mm. Achenes elliptic to ± orbiculate, 1.6-2.2 × 1.2-1.6 mm, 0.5-0.7 mm thick, apiculum to 0.4-1.1 mm. 2n =50, 52, 54.

Fruiting early summer. Prairie swales; 100-400 m; Ill., Ind., Iowa, Kans., Mo., Nebr.