Culms 5-40 cm. Leaves: blades 5-15(-25) cm × 1-2.5(-3.5) mm. Inflorescences: proximal bracts leaflike, exceeding inflorescences, sheaths to 10 mm; lateral spikes with 9-30 perigynia, approximate or proximal distant, dense, 7-15 × 3-5 mm; middle internodes 0.3-0.7 mm; terminal spike usually gynecandrous, with at least 1/3 of flowers staminate, rarely entirely staminate, sessile or short-pedunculate, 6-15(-20) mm, (1.2-)1.5-2.5 mm wide in staminate portion. Pistillate scales ascending, medium to dark brown with paler midvein and hyaline margins, ovate-circular, 1.7-2.7 × 1-1.9 mm, apex obtuse to acute, sometimes shortly mucronate. Staminate scales brown with paler midvein and hyaline margins, oblong-ovate, (2-)2.5-3.7 mm, apex obtuse to acute. Perigynia ascending, white, elliptic-obovate, 2-3 × 1.2-1.8 mm, densely papillose. Achenes elliptic-circular, 1.4-2 × 1-1.5 mm. Fruiting summer. Moist shores, meadows, fens, on base-rich soils; 0-1500 m; Alta., B.C., Man., N.B., N.W.T., Nunavut, Ont., Que., Sask., Yukon; Alaska, Calif., Ind., Maine, Mich., Minn., N.H., N.Y., N.Dak., Ohio, Oreg., Pa., Utah, Vt., Wash., Wis., Wyo.