Herbs, perennial, cespitose, bases cormose, rhizomatous. Culms trigonous, 5-50 cm × 0.5-1.5 mm, glabrous. Leaves V-shaped, 12-30 cm × 1-6 mm. Inflorescences: spikes ± globose to broadly ovoid, 8-20 mm wide; rays 1-8 cm; rachis 2-5 mm, glabrous; bracts 3-8, weakly ascending, flat, 3-20 cm × 1-3.5 mm; rachilla deciduous, wingless. Spikelets 3-18, compressed, ovoid to oblong-lanceoloid, 4-15 × 2.6-3.4 mm; floral scales deciduous, 3-18, laterally stramineous to reddish brown, laterally 3-4-ribbed, broadly ovate, 1.8-2.5 × 1.3-1.6 mm, apex with mucro 0.1-0.2 mm. Flowers: anthers 0.5-0.7 mm; styles 0.4-0.6 mm; stigmas 1-1.5 mm. Achenes dark brown, sessile, broadly ellipsoid, 1.5-2 × 1-1.5 mm, apex obtuse, apiculate, surface glabrous, puncticulate, or papillose. 2n = 168, 170, 172. Fruiting summer. Riverbanks, sand bars, lakeshores, sand dunes, sandy openings in woods, especially among Jack pines; 0-1100 m; Man., Ont., Que.; Ill., Ind., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., Ohio, Pa., Vt., Va., W.Va., Wis.