Culms 2-6.5(-9.1) cm, tallest ones 3.2-9.1 cm. Leaves: basal sheaths reddish brown; blades green, eceeding culms, 2-4(-5) mm wide, coriaceous, margins green, scabrous. Lateral spikes 1-3, basal, on erect to spreading peduncles. Terminal spikes with staminate portion (5-)7-15(-21)-flowered, 3-8 × 0.6-1.2 mm; pistillate portion (2-)4-9-flowered. Pistillate scales green, margins 1.2-3 mm wide, not more than 1.5 times as wide as and not concealing perigynia, apex long-acute; distal scales with hyaline margins to 0.3 mm wide, apex acute, awnless. Staminate scales green, tinged brown or reddish brown, ovate to oblong, 0.8-1.5 × 0.8-1.2 mm, margins connate for most of their length, enfolding scales above, hyaline, white, apex truncate to obtuse (sometimes mucronate), erose. Anthers 1-1.5 mm. Perigynia green, sometimes flecked with reddish brown, obovoid to ellipsoid, 3.8-5.1 × 1.5-2 mm, tightly enveloping achenes, apex abruptly tapering; beak (1.2-)1.4-2.1 mm, scabrous. Stigmas filiform, flexuous, long, slender, strongly papillose. Achenes dark brown, globose to ellipsoid, 1.9-2.5 × 1.5-2 mm.
Fruiting spring-summer (early May-late Jun). Open, vernally moist, red juniper-oak glades, alvars, prairie openings, on clay soils derived from crumbling limestone; of conservation concern; 100-300 m; Ont.; Ky., Ohio, Va.