Herbs, annual, densely cespitose, scapose, low. Culms 5–20(–30) cm. Leaves to 2/3 length of scapes; sheaths greenish or tan, glabrous or hispidulous on ribs; blades spreading, filiform, 0.5 mm wide, involute, margins scabridulous. Inflorescences: scapes filiform, coarsely few ribbed, to 0.5 mm thick; spikelets in terminal headlike, involucrate clusters, 1–1.5 cm wide; involucral bracts with setaceous blades rarely exceeding inflorescence. Spikelets red to red-brown or dull brown, lance-ovoid to lanceoloid or linearoblong; fertile scales lanceolate, keeled, 1.2–2.2 mm, glabrous, midrib excurrent as mucro. Flowers: stamens 1; anthers oblong, 1 mm. Achenes trigonous, obovoid, 0.5–0.6 mm, angles often sharp, faces flat or slightly concave, finely reticulate; tubercle a small button. 2n = 10.
