Plants densely cespitose. Culms 25-60(-85) cm; vegetative culms with few leaves clustered at apex. Leaves: sheaths adaxially white-hyaline, summits U-shaped; distal ligules 1.5-6 mm; blades (2-)3-4(-5) per fertile culm, 7-22 cm × 2-4 mm. Inflorescences erect, usually dense, green, gold, or dark brown, 1.8-3 cm8-14 mm; proximal internode 2-3(-5) mm; 2d internode 1-3 mm; proximal bracts bristlelike, shorter than or equaling inflorescences. Spikes 6-14, distant, distinct, ovoid to broadly ovoid, 8-10 × 4.5-6.5 mm, base and apex acute to truncate. Pistillate scales gold to dark brown, with whitish, green, or brown midstripe, lanceolate, 3-3.8 mm, shorter and narrower than perigynia, apex acuminate to short-awned. Perigynia ascending, white to gold or light brown, 0-5-veined abaxially, 0-4-veined adaxially, narrowly lanceolate to narrowly ovate, flat except over achene or, occasionally, plano-convex, 3.4-4.1(-4.7) × 0.9-1.3 mm, 0.15-0.35 mm thick, margin flat, including wing 0.1-0.2 mm wide, usually crinkled distally; beak brown or red-brown at tip, flat, ± ciliate-serrulate, abaxial suture inconspicuous, distance from beak tip to achene (1.8-)2.1-3 mm. Achenes ± elliptic, 1.1-1.5 × 0.6-0.8 mm, 0.15-0.35 mm thick; style usually persistent, sinuate. 2n = 52, ca. 66, 70. Fruiting late spring-summer. Often in standing water, moist to wet places, open, sandy, dryish disturbed areas; 100-1500 m; Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon; Alaska, Conn., Idaho, Maine, Mass., Mich., Minn., Mo., Mont., N.H., N.J., N.Y., Oreg., Pa., Vt., Wash., Wis.
Tufted, 2-7 dm, aphyllopodic; main lvs 1-3 mm wide, shorter than the stems; sheaths ventrally hyaline; spikes 5-12, gynaecandrous, 5-10 mm, subglobose to oblong, pale greenish to dull- stramineous or tan, sessile in a compact spike or narrow head 1.5-3 cm; bracts inconspicuous, or the lowest one to about as long as the infl; pistillate scales shorter and narrower than the perigynia, sometimes mucronulate; perigynia appressed-ascending, planoconvex and not much wider than the achene, 3.3-4 נ0.8-1 mm, 3.5-5 times as long as wide, lightly few-nerved on both sides or nearly nerveless especially ventrally, narrowly wing-margined and serrulate, especially distally, tapering gradually into the slender, distally terete beak; achene lenticular, 1-1.3 נ0.6-0.7 mm; 2n=68, 70. Wet soil, meadows, swamps, and shores; Nf. to B.C., s. to N.J., Mich., Minn., and Wash.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.