Culms erect or spreading, (3.1-)8.2-29.7 cm, 0.4-0.9 of total plant height. Leaves: basal sheaths pale to medium brown; blades green, exceeding culms, 1.3-3.2 mm wide, herbaceous, margins green, smooth or slightly scabrous. Lateral spikes (0-)2-4, basal, on widely spreading to nodding peduncles. Terminal spike with staminate portion 3-29-flowered, 3.4-8.6(-10.3) × 0.7-1.4 mm; pistillate portion 3-9-flowered. Pistillate scales green, margins hyaline, white, often with reddish brown tinge, 1.6-2.22 mm wide, not more than 1.5 times as wide as and not concealing perigynia, apex attenuate into green awns; distal scales with hyaline margins 0.3-0.8 mm, apex acute, awnless. Staminate scales green or tinged with brown subapically, 1.4-2.8 × 1.8-2.2 mm, margins free but enfolding scales above, hyaline, white, apex obtuse, erose. Anthers 0.9-1.1 mm. Perigynia 3-9 per spike, pale green to olive or pale brown, unspeckled, narrowly ovoid to lance-ovoid, (4.5-)4.9-5.7(-6.5) × 1.2-1.7 mm, 1.2-2.2 times as long as wide, tightly enveloping achenes, apex gradually tapering; beak (1.7-)1.9-2.6(-2.8) mm, scabrous. Stigmas filiform, flexuous, long, slender, strongly papillose. Achenes brown, oblong, (1.8-)2.1-2.5(-2.6) × (1.2-)1.3-1.5(-1.6) mm. 2n = 62, 78.
Fruiting spring-summer (late Apr-late Jul). Acidic, dry mesic, open, oak-dominated woodlands, often on ridges and slopes; 50-900 m; Ont.; Ala., Ark., Conn., Del., D.C., Ill., Ind., Ky., Md., Mass., Mo., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Vt., Va., W.Va.
The Carex willdenowii group (C. willdenowii, C. basiantha & C. superata) differs from the other members of the section in having asynchronous spike production, resulting in a protracted fruiting season (R. F. C. Naczi et al. 1998).
Tufted, the stems weak and slender, 0.5-3 dm, much shorter than the lvs, distally winged triquetrous; main lvs 2-4 mm wide; spikes 1-3, androgynous, the lower widely separated, nearly basal, on long, capillary peduncles; staminate scales obtuse or acute; pistillate scales dilated at base, with hyaline margins, the lowest ±foliaceous, surpassing the perigynium and sometimes the whole spike, the others narrower than the perigynia; perigynia 3-8, green or greenish, 4.5-6 mm, the body obovoid-oblong above the short stipe-like base, nerveless, sharply 2-edged above, tapering into the very rough, triangular-pyramidal beak, which constitutes a third to half of the entire
length; achene rounded-trigonous, with a short stylar apiculus. Moist woods, especially in acid soils; chiefly in the coastal states from Mass. to Ga. and Tex., but also inland to O., Tenn., and s. Ind.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.