Culms to 125 cm. Leaves: sheaths glaucous, fronts indistinctly veined, veins not persisting, apex thin, truncate or irregularly convex; blades 120 cm × 7-10 mm, glabrous. Inflorescences with 5-7 spikes, 30 cm; peduncle of lateral spikes to 6 cm; proximal bracts equaling inflorescences, 3-6 mm wide; lateral spikes divergent, 3-6 cm × 6-8 mm. Pistillate scales shorter and narrower than perigynia, apex acute, awn to 3 mm. Perigynia strongly divergent, red-brown, angles veined, faces prominently 6-8-veined, sessile, widely elliptic or somewhat obovate, 3.5-4.5 × 2.8-3.2 mm, base rounded, apex ± truncate proximal to beak, densely papillose with low, oblong or, rarely, minute, rounded papillae, not markedly glaucous; beak 0.3-0.5 mm, entire or minutely bidentate, teeth to 0.1 mm. Achenes rhomboid, 2.5-3 × 2.5-3 mm, base conspicuously broadened.
Fruiting Aug-Sep. Seasonally saturated or inundated soils in moist, swampy, or bottomland woods, or stream banks; 0-800 m; Ala., Ark., Fla., Ga., Ky., La., Md., Miss., Mo., N.C., S.C., Tenn., Tex., Va.
Carex joorii is more robust than C. glaucescens and can be distinguished from C. glaucesens and C. verrucosa by the acute apex of the scale body, the strongly veined, squarrose perigynia with low, flattened papillae, and the broadened base of the achene. Occasional specimens have been observed with papillae characteristic of C. glaucescens; such specimens may result from hybridization.
Vigorously colonial from stout creeping rhizomes, 4-13 dm, stout; main lvs elongate, glaucous, 5-10 mm wide; staminate spike 3-5 cm; pistillate spikes 3-5, separate but overlapping, 2-6 cm, staminate at the tip, usually ±erect, the lower long-peduncled, the upper less so or subsessile; lowest bract lf- like, the upper much reduced and setaceous; pistillate scales oblong, the body shorter than the perigynium, brown- tinged, the midvein prolonged into a rough awn; perigynia dull green and glaucous when young, becoming brown, broadly obovoid, 3.2-5 mm, tapering to the base, conspicuously several-nerved, broadly rounded above into a prominent, short beak with an entire orifice; achene concavely trigonous. Wet woods and swamps, mainly on the coastal plain; se. Va. (and reputedly Md.) to Fla. and Tex., n. in the interior to se. Mo. and McCreary Co., Ky.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.