Plants cespitose or single-stemmed. Culms 20-90 cm × 0.9-1.2 mm distally. Leaves: blades flat, trigonous in cross section distally, to 30 cm × 2-6 mm; distal leaf blade much longer than sheath. Inflorescences: blade-bearing involucral bracts 2-4, sometimes brown-tinged proximally, leaflike, to 7 cm. Spikelets 3-30, in subumbels, lax, oblong-ovoid, 6-10 mm in flower, 15-30 mm in fruit; peduncles (2-)10-60 mm, scabrous; scales dark green to gray, pale proximally, darker distally, ovate to lanceolate, 4-6 mm, margins scarious 0-0.1 mm wide, to 12 weak lateral ribs, midrib prominent, enlarged distally, reaching tip, sometimes excurrent, apex acute. Flowers: perianth bristles 10 or more, white to pale brown, 15-25 mm, smooth; anthers 0.8-2 mm. Achenes dark brown, narrowly obovoid, 2.5-3.5 mm. Fruiting summer. Marshes, meadows, bogs, fens, wet woods; 0-2000 m; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Ont., P.E.I., Que., Sask.; Alaska, Colo., Conn., Idaho, Ill., Ind., Iowa, Maine, Mass., Mich., Minn., N.H., N.Y., N.Dak., Ohio, Pa., R.I., Vt., Wis., Wyo.