Description from Flora of China
Perennials. Culms usually thick, often rooting from the lower nodes. Leaf blades flat or involute; ligule a ciliate rim. Inflorescence of short erect racemes; racemes imbricate or distant along the central axis, spikelets borne singly, usually imbricate in 2 neat rows, sometimes also on short basal branchlets; rachis (and branchlet when spikelets clustered) terminating in an inconspicuous point or bristle. Spikelets dorsally compressed or often strongly convex, florets 2; glumes membranous to herbaceous, rounded, lower abaxial, short and broad, upper 1/2 as long to equaling the spikelet; lower floret staminate or neuter, lemma resembling upper glume, lower palea present or absent; upper lemma coriaceous to bony, margins inrolled or only narrowly hyaline; upper palea apex often briefly reflexed. x = 9.
Most species of Paspalidium are clearly distinct from Setaria, with a completely different appearance, so for that reason the two genera are maintained here. However, some species of Setaria with very few bristles (especially in Australia) are intermediate, and Paspalidium is included within Setaria by some authors. Setaria yunnanensis is the only intermediate species in China.
About 40 species: throughout the tropics, especially Australia; two species in China.
(Authors: Chen Shouliang (陈守良); Sylvia M. Phillips)