Plants slender, grasslike, to 0.8 m; leaves and inflorescences usually floating. Leaves limp, unkeeled, flat, 0.1--0.4(--0.8) m 1--5 mm. Inflorescences: rachis unbranched, flexuous; bracts ascending, lower bracts slightly inflated near base; pistillate heads 1--4, axillary, contiguous, sessile, or most proximal peduncled and supra-axillary, 0.5--1.4 cm diam. in fruit; staminate heads 1(--2), terminal, contiguous or not with distalmost pistillate head. Flowers: tepals without subapical dark spot, erose; stigmas 1, ovate. Fruits brown or yellowish, dull, subsessile, body ellipsoid to obovoid, not faceted, ±more or less constricted at equator, 2--5 1.5--2.5 mm; beak less than 0.5 mm, or absent; tepals attached at base, not reaching equator. Seeds 1. 2n = 30.
