Conservation Status: Not of concern
Annual, perennial herb 20-100 cm, internal air cavities evident; rhizome 1-2 mm diam, tough, scaly, no bulb or tuber at tip; stems simple, erect, smooth, 0.5-2.5 mm diam, cylindric to flat; tip not rooting.
Leaves 2; distal sheath tough, persistent, tip truncate to obtuse, sometimes with tooth-like projection smaller than 1 mm.
Inflorescence composed of 1 spikelet 5-40 mm x 2-5 mm, spikelet terminal, often ovate, not flat, generally not forming plantlets; floral bracts 2-ranked, bracts number 30-80 each with 1 flower in axil, ovate, brown, membranous, 2.5--5.5 mm, basal without flower, some clasping most of stem, next-to-basal with flower or not; flowers number 3-100+, bisexual, perianth parts reduced to bristles numbering 0-8, barbs recurved; stamens generally 3, anthers 1.3--2.7 mm long; style 1, thread-like, base enlarged, stigmas 2.
1.1-1.9 x 0.8-1.5 mm, 2-sided, smooth or fine-roughened, generally obovate, generally brown; perianth bristles 0 or 4, vestigial to equaling tubercle, generally pyramidal.