Plants without conspicuous rhizomes. Culms 20-90 cm, (1.5-) 1.6-2.2 mm wide basally, 0.5-0.9 mm wide distally. Leaves: sheaths tight, green, fronts hyaline; ligules less than 2 mm, wider than long; widest leaf blades 1.8-2.6 mm wide. Inflorescences 2-7 cm × 5-8 mm; proximal internodes more than 2 times as long as proximal spikes; proximal bracts to 6(-10) cm; spikes with 7-14 spreading perigynia; spikes 4-8. Pistillate scales hyaline with green midvein, ovate to circular-ovate, 1.4-2.1 × 1-1.8 mm, body 1/2 length of perigynium, apex obtuse, acute, or awned. Anthers 0.8-1.3 mm. Perigynia green, faces not veined, 2.6-4(-4.2) × 1.1-1.8 mm, base of body spongy, thickened, longitudinally striate adaxially, spongy region 0.8-1.3 mm, margins serrulate distally; beak 0.6-1.2 mm, apical teeth 0.1-0.5 mm. Stigmas coiled or twisted, 0.07-0.1 mm wide. Achenes ovate to obovate, 1.6-2.2 × 1.1-1.6 mm. 2n = 52. Fruiting mid-late spring. Dry to mesic deciduous or mixed forests; 50-1000 m; Man., N.B., N.S., Ont., Que.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Vt., Va., W.Va., Wis., Wyo.
Much like nos. 26 [Carex radiata (Wahlenb.) Small] and 27 [Carex appalachica J. M. Webber & P. W. Ball], but more robust; fertile stems erect, 1.5-2.2 mm thick at base; widest lvs 1.8-2.6 mm wide; perigynia radiating in all directions, 2.6-4.2 mm, the base cuneate to rounded; achene set low in the perigynium, as in no. 27 [Carex appalachica J. M. Webber & P. W. Ball]; stigmas a little stouter, 0.07-0.1 mm wide, once or twice coiled; 2n=52. Mostly in habitats a little drier than those of no. 26, a littler moister than those of no. 27; N.S. and s. Que. to Minn. and e. Nebr., s. to Ga., Tenn., and Ark. (C. convoluta)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.