Tufted, 2-6 dm; fertile stems triangular and slightly winged, roughened on the angles; basal sheaths mostly brown, but the immediately suprabasal ones often purple; lvs of the sterile shoots 10-50 mm wide, of the fertile ones 4-16 mm; angles of the bract-sheaths minutely ciliate-serrulate; terminal spike staminate, 0.5-2 cm, sessile or nearly so, often hidden by the uppermost pistillate spike and its bract; pistillate spikes 3 or 4, 1-3 cm, the uppermost one or 2 near the staminate peduncle, the others remote, on short to elongate peduncles, none basal; pistillate scales broadly obtuse or subtruncate, only minutely apiculate; perigynia 3-20, ±overlapping, 3-4.2 mm, greenish-stramineous, finely many-nerved as well as 2-ribbed, obtusely trigonous, obovoid, with a short, abruptly bent beak; achene convexly trigonous; 2n=44. Rich woods, especially in calcareous regions; Vt. and s. Que. to Minn., s. to S.C. and Ark. (C. laxiflora var. latifolia)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.