Plants without conspicuous rhizomes. Culms 20-60 cm, 2-3.5 mm wide basally, 0.5-1 mm wide distally. Leaves: sheaths tight, green, rarely white spotted, fronts hyaline, slightly thickened at mouth; ligules to 5 mm, longer than wide; widest leaf blades (1.9-)2.5-5 mm wide. Inflorescences forming dense heads, with 3-8 spikes, 0.6-2 cm × 5-10 mm; proximal bracts 1-5 cm; spikes with 4-20 ascending to spreading perigynia. Pistillate scales hyaline with green midvein, ovate, 1-1.8 × 0.8-1.4 mm, body not more than 1/2 length of perigynium, apex acuminate to short-awned. Anthers 0.7-1.3 mm. Perigynia pale green to pale yellow, veinless or to weakly 8-veined abaxially, 2.5-3.2 × 1.4-2 mm, body elliptic to circular, widest at 0.4-0.55 length of body, margins serrulate distally; beak 0.7-1.1 mm, apical teeth 0.3-0.5 mm. Achenes circular, 1 × 1 mm. 2n = 48. Fruiting late spring-early summer. Dry to wet-mesic deciduous or mixed forests, thickets, rarely open grassy habitats; 50-500 m; Ont., Que.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Mass., Md., Mich., Minn., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wis. The record of Carex cephalophora from California is referable to C. mesochorea.
From Flora of Indiana (1940) by Charles C. Deam
Very common in oak and beech-maple woods; occasional along open grassy roadsides and in thickets.
Densely cespitose, the stems 3-6 dm, slightly shorter to more than twice as long as the lvs; lvs 2-5 mm wide; spikes in a dense ovoid head 1-2 cm, scarcely distinguishable except by the setaceous projecting bracts, subglobose, 5 mm, androgynous; perigynia greenish or somewhat stramineous, spreading, ovate, planoconvex, 2.5-3.5 mm, two-fifths to three-fifths as wide shortly below the middle of the body, rounded or cuneate at base, conspicuously serrulate distally, the sharply bidentate beak a third as long as the body. Var. cephalophora, abundant in dry or moist woods, occasionally in open places, from Me. and sw. Que. to Man., s. to Fla. and Tex., has the pistillate scales broadly ovate, hyaline at the margin, green along the center, with green midnerve and 2 obscure lateral nerves, acuminate to short-awned, and the body much shorter than and mostly concealed by the perigynia. Var. mesochorea (Mack.) Gleason, of dry soil and open woods from Mass. to Va., Ind., Mo., Tenn., and Tex., has the stems usually much longer than the lvs, and has much larger pistillate scales, the body nearly or quite as long as the body of the perigynium, distinctly 3-nerved near the center. (C. mesochorea)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.