Herbs, perennial, cespitose, not rhizomatous, 1.4--10 dm. Culms erect, terete, 1--3 mm diam., smooth. Cataphylls 1--2, gray, apex acute. Leaves: basal 1--2, cauline 1--2; auricles 1--1.5 mm, apex rounded, scarious; blade green, straw-colored, or pink, nearly terete, 1--40 cm. Inflorescences terminal panicles of 5--50 heads, 5--15 cm, branches ascending; primary bract erect; heads (2--)5--20(--50)-flowered, hemispheric (to spheric), 3--10 mm diam. Flowers: tepals light brown to greenish, lanceolate, 2.6--3.5(--3.9) mm, apex acuminate; stamens 3 (or 6), anthers 1/3 filament length. Capsules equaling perianth or slightly exserted, straw-colored, 1-locular, ellipsoid to narrowly ovoid, 2.8--3.5(--4) mm, apex acute, valves separating at dehiscence, fertile throughout or only proximal to middle. Seeds ellipsoid to oblong, 0.3--0.4 mm, not tailed; body clear yellow-brown. 2n = 40. Fruiting early summer--fall. Shores, swamps, ditches, springs, wet meadows, and rock outcrops; 0--2200 m; B.C., N.S., Ont., Que.; Ala., Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., N.H., N.J., N.Mex., N.Y., N.C., Ohio., Okla., Oreg., Pa., R.I., S.C., Tenn., Tex., Vt., Va., Wash., W.Va., Wis.; Mexico; Central America (Honduras).