Herbs, perennial, rhizomatous, 2.5--6 dm. Rhizomes 1 mm diam., with swollen nodes. Culms erect, terete, 1--3 mm diam., smooth. Cataphylls 0 or 1--2, straw-colored, apex rounded. Leaves: basal 0--1, cauline 3--5, auricles 1.5--2.5 mm, apex rounded to acutae, scarious; blade straw-colored to green, terete, 5.5--20 cm x 1--2.5 mm. Inflorescences terminal panicles of 2--16 heads, 2.5--6 cm, branches ascending, spreading, or reflexed; primary bract erect to spreading; heads 10--40-flowered, spheric, 11--15 mm diam. Flowers: tepals green or straw-colored to reddish brown, lance-subulate, apex acuminate; outer tepals (3.5--)4--4.9 mm; inner tepals 3.9--5.4 mm; stamens 6, anthers 2--3 times filament length. Capsules exserted, chestnut brown, 1-locular, lance-subulate, 5.2--6.5(--8) mm, apex tapering, valves separating at dehiscence, fertile throughout or only proximal to middle. Seeds obovoid, 0.45--0.5 mm, not tailed; body clear yellow-brown.

Fruiting summer. Swamps, depressions, seeps, sand or gravel bars, and wet mud; 400--600 m; La., Okla., Tex.