Plants not cespitose; rhizome internodes 2-3.4 mm thick. Culms strongly purple-red or yellow-brown tinged with purple-red to 4.8-10.4 cm high at base, 20-60(-68) cm. Leaves: sheaths glabrous; blades green, widest blades 2.4-5.1(-6.7) mm wide, smooth abaxially. Inflorescences 0.21-0.57(-0.95) of culm height; peduncles of lateral spikes scaberulous; peduncles of terminal spikes (2.5-)18-121 mm, usually much exceeding lateral spikes; proximal bract with sheaths tight, abaxially glabrous, sheath front apex concave, elongated 0.2-2.5 mm; ligules 0.2-4.3 mm; distal bract shorter than terminal spike. Spikes 1-3, widely separate; lateral spikes pistillate or androgynous, with 3-13(-22) perigynia, (19-)13-39 × 3.9-8.3 mm, ratio of spike length (in mm) to flower number = 1.7-3.4; terminal spikes (16-)20-43 × (2.8-)3.3-4.5(-5.4) mm. Pistillate scales 3.3-11.1(-17.9) × 2-2.8 mm, margins entire, whitish, apex with awn 0.2-8.3(-13.7) mm. Staminate scales 4.2-5.7 × 1.2-1.6 mm. Anthers 2.4-4.4 mm. Perigynia spirally imbricate, 42-65-veined, unwrinkled, obovoid or narrowly obovoid, obtusely triangular in cross section, 3.4-5.1 × 1.5-2 mm, 1.8-2.5(-3.2) times as long as wide, dull, base gradually tapered, apex gradually or abruptly tapered to subacute; beak absent or excurved, 0-0.4(-1.2) mm. Achenes obovoid, 2.6-3.4 × 1.4-1.8 mm, tightly enveloped by perigynia; stipe 0.1-0.3(-0.6) mm, bent 30-60°; beak bent 35-80°, 0.25-0.45 mm.

Fruiting spring. Mesic to dry-mesic, rocky, deciduous or deciduous-pine forests, usually in loams on slopes or ridgetops; 200-800 m; Ark., Ky., Okla., Tenn.

Though it has a restricted distribution and is local, Carex ouachitana is often abundant where it occurs.