Description from Flora of China
Annual or perennial. Leaf blades linear, flat; ligule membranous. Panicle contracted to dense and spikelike, often bristly with numerous small deciduous spikelets. Spikelets with 1 floret, laterally compressed, without rachilla extension, falling entire, pedicel or upper part of it articulated and remaining attached to spikelet as a stipe; glumes equal, longer than floret, papery, scabrid, 1-veined, apex entire to 2-lobed, often with slender awn from apex; lemma about 1/2 as long as glumes, rounded, thin, smooth, shiny, obscurely 5-veined, veins usually shortly excurrent from truncate apex, awnless or with fine subapical awnlet or geniculate dorsal awn; palea 1/2 as long to equaling lemma. Stamens 1–3.
Polypogon is closely related to Agrostis, with which it hybridizes. It is distinguished mainly by its deciduous spikelets falling with a slender, basal stipe attached.
Twenty-five species:warm-temperate regions of the world and on tropical mountains, especially in damp places; six species (one endemic) in China.
(Authors: Lu Shenglian (卢生莲); Sylvia M. Phillips)