Plants densely to loosely cespitose. Rhizomes short to long, internodes 0.2–20 mm. Culms 0.5–1(–1.1) mm wide. Widest leaf blades 1.3–2.9(–3.1) mm wide. Longest inflorescences (33–)40–63(–71) mm. Perigynium beak 0.3–0.42 times as long as perigynium. 2n = 64, 66, 68.

Fruiting spring–early summer. Forested flood plains, wet hardwood forests, hardwood swamps, occasionally wet meadows, marsh edges; 0–500(–1100) m; N.B., N.S., Ont., Que.; Ala., Ark., Conn., D.C., Del., Fla., Ga., Ill., Ind., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.; c Mexico.