Culms 20-80 cm, pilose. Leaves: sheaths pilose; ligules longer than wide; blades 2-3 mm wide, pilose abaxially. Inflorescences: lateral spikes approximate or proximal distant, 5-20 × 4.5-7 mm; terminal spike staminate, 5-30 × 1-2.5 mm. Pistillate scales ovate, 2.2-3.2 × 1.1-1.5 mm, 2 times as long as wide, apex of proximal cuspidate, apex of distal acute or acuminate, as long as perigynia. Staminate scales oblong-obovate, 2.7-4.2 mm, apex acute or mucronate. Anthers 1.4-2.8 mm. Perigynia ascending or somewhat spreading, weakly 14-20-veined, elliptic-oblong, 2.3-3 × 1.1-1.5 mm, glabrous; beak absent. Achenes 1.8-2 × 1-1.2 mm. 2n = 70. Fruiting summer. Meadows, open slopes; 0-500 m; St. Pierre and Miquelon; N.B., Nfld. and Labr., N.S., Ont., Que.; Conn., Maine, Mass., Mich., Minn., N.H., N.J., N.Y., Ohio, Pa., R.I., Vt.; Eurasia; introduced New Zealand.
Tufted, 2-5 dm; main lvs 2-4 mm wide, soft-hairy, especially on the lower side and on the sheaths, varying to glabrous; terminal spike peduncled, staminate, 1-2 cm; pistillate spikes 2-4, densely fld, short-cylindric, 8-15 mm, the lower short-peduncled, the upper subsessile; lower bracts exceeding the infl, the upper much smaller; anthers 1.7-2.8 mm; pistillate scales ovate, about as long as the perigynia, pale green, faintly brown-tinged, acute to cuspidate; perigynia ascending, ellipsoid, 2.1-2.8 mm, nearly round in cross-section, obscurely and finely nerved, beakless, obtuse; achene concavely trigonous. Moist woods and meadows; Nf. to Wis., s. to N.J. and O.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.