Culms 30-100 cm, sparsely pilose. Leaves: sheaths pilose; ligules longer than wide; blades 2-4 mm wide, pilose. Inflorescences: lateral spikes (18-)20-35 × 2.5-3.5 mm, proximal distant; terminal spike gynecandrous, at least 1/2 of flowers pistillate, 20-35(-40) mm. Pistillate scales ovate-circular, 1.5-2.5(-3.2) × 0.9-1.2 mm, apex of proximal obtuse, with awn to 0.5 mm, apex of distal acute to acuminate, as long as perigynia. Staminate scales ovate, 2.8-4.1 mm, apex obtuse to acuminate. Anthers (1-)1.6-2(-2.8) mm. Perigynia ascending, distinctly 7-12-veined, elliptic, trigonous in cross section, 1.9-2.5 × 1-1.4 mm, densely pilose; beak absent. Achenes 1.5-2 × 0.8-1.1 mm. 2n = 60. Fruiting late spring-early summer. Dry to wet-mesic deciduous forests, banks; 0-1000 m; Ont., Que.; Ark., Conn., Del., D.C., Ga., Ind., Ky., Maine, Md., Mass., Mich., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Va., W.Va.
From Flora of Indiana (1940) by Charles C. Deam
Fairly common in the southern counties, especially in the knob area (Chestnut Oak Upland), on wooded bluffs, slopes, and river banks; infrequent in level woods. It is known from the lake area from a single collection and most reports from the northern third of the state were doubtless based upon material of C. Swanii.
Tufted, 5-10 dm, reddish-purple at base, the stems usually overtopping the lvs; main lvs 2-4 mm wide, hairy; terminal spike 2-4 cm, pistillate above; pistillate spikes 2-4, erect, 2-4 cm, linear-cylindric, loosely fld at base, sessile or short-peduncled; bracts sheathless or nearly so, the lowest foliaceous, the upper much reduced; anthers 1.5-2.5 mm; pistillate scales ovate, shorter than to surpassing the perigynia, hyaline-margined, with green midvein, acute to cuspidate; perigynia obscurely trigonous, ±ellipsoid, 2-3 mm, densely hairy, conspicuously few-ribbed, acute, beakless; achene concavely trigonous. Dry woods; Me. to Mich., s. to N.C., Ga., and Mo.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.