Plants colonial from long-creeping rhizomes. Culms 40-120 cm × 0.6-1 mm, smooth or scabrous distally. Leaves: blades flat, trigonous in cross section distally, to 30 cm × 1.5-4 mm; distal leaf blade much longer than sheath. Inflorescences: blade-bearing involucral bracts 2-5, sometimes brown-tinged proximally, leaflike, longest 4-12 cm. Spikelets 2-10, usually in dense head, ovoid, 6-10 mm in flower, 10-20 mm in fruit; peduncles 2-10(-20) mm, scabrid; scales brown, often with green center, ovate-oblong, 4-5 mm, obscurely ribbed or with 3-5 equally prominent ribs, apex obtuse. Flowers: perianth bristles usually 10 or more, brown at least at base, rarely entirely white, 12-18 mm, smooth; anthers 0.7-1.5 mm. Achenes dark brown to black, narrowly obovoid or ellipsoid, 2.5-4 mm. Fruiting mid summer-early fall. Bogs, meadows; 0-1000 m; St. Pierre and Miquelon; N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que.; Conn., D.C., Ill., Ind., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va., Wis.