Description from Flora of China
Orthopogon R. Brown, nom. rej.
Perennials or annuals. Culms trailing, ascending from a decumbent base, the internodes mostly with a villous line adaxial to the subtending leaf. Leaf blades ovate, lanceolate or linear-lanceolate, often with cross veins; ligule a ciliate membrane. Inflorescence composed of several unilateral racemes spaced along a central axis; racemes elongate or reduced to fascicles of a few spikelets, spikelets usually paired on short pedicels, the lowermost often reduced. Spikelets lanceolate to oblong, weakly dorsally or laterally compressed, florets 2; glumes subequal, 1/2–3/4 spikelet length, often pilose, the lower or both tipped by a viscid awn; lower lemma equaling the spikelet, acute to shortly awned, its palea absent or much reduced; upper lemma papery or subcoriaceous, smooth and shiny, acute, indistinctly crested. x = 9.
This is a genus of closely related, intergrading species where the number of taxa meriting recognition is still open to doubt.
Five to nine species:throughout the tropics and subtropics; four species (one endemic) in China.
(Authors: Chen Shouliang (陈守良); Sylvia M. Phillips)