Culms 25-80 cm, glabrescent. Leaves: sheaths pilose; ligules as long as or shorter than wide; blades 1.5-4 mm wide, glabrescent or pilose abaxially and/or proximally. Inflorescences: lateral spikes usually approximate, 7-18 × 3.5-5 mm; terminal spike gynecandrous, at least 1/2 of flowers pistillate, 12-25 mm. Pistillate scales ovate, 1.5-2.4(-3) × 0.7-1.5 mm, shorter than perigynia, apex acute to acuminate. Staminate scales oblong-ovate, 2.4-5.1 mm, apex acuminate. Anthers 1.4-2.5 mm. Perigynia spreading, 7-14-veined, obovate-circular, nearly circular in cross section, 2.1-3 × 1.1-2 mm, not papillose, glabrous or sparsely pilose; beak absent. Achenes 1.6-2.2 × 1-1.4 mm. 2n = 48. Fruiting late spring-early summer. Ditches, shores; 0-500 m; Ark., Del., D.C., Ga., Ind., Kans., Md., Miss., Mo., N.J., N.C., Ohio, Okla., Pa., Tenn., Tex., Va., W.Va.