"Partially submerged rhizomatous perennials; rhizome creeping, clothed with brown scales; culms 30-65 cm high, partially submerged and spongy. spikelets 30 x 3.5 mm, linear-oblong, cylindric; glumes 4.5 x 4 mm, broadly ovate, obtuse, 1-nerved, concave; margin striate with red lines; bristle 3.5 mm long, pale brown; stamens 3, anthers 2.5 mm long; style base wider than ovary. Nut 2 x 1.5 mm, obovoid, obtuse, longitudinally striate; epidermal cells transversely oblong."