Description from Flora of China
Andropogon subg. Sorghum Hackel.
Perennial or annual, with or without rhizomes. Culms usually robust, erect. Leaf blades linear to linear-lanceolate; ligule a ciliate membrane. Inflorescence a large terminal panicle with elongate central axis; primary branches simple or branched, bearing short dense racemes of paired spikelets; racemes fragile (tough in cultivated species); rachis internodes and pedicels slender, ciliate. Sessile spikelet dorsally compressed; callus obtuse, bearded, inserted into internode apex; lower glume usually leathery, shallowly convex, rounded on flanks, becoming 2-keeled and winged upward, usually hairy, apex membranous; upper glume boat-shaped, keeled upward; lower floret reduced to an empty hyaline lemma; upper lemma 2-toothed, awned from sinus or infrequently awnless; awn bigeniculate, glabrous. Lodicules ciliate. Pedicelled spikelet well developed or reduced to a glume, usually much narrower than sessile spikelet, awnless.
The genus includes species of agricultural importance, including the tropical cereal sorghum, and several species grown for forage.
About 30 species: tropics and subtropics of the Old World, one species endemic to Mexico, otherwise introduced in America; five species (three introduced) in China.
(Authors: Chen Shouliang (陈守良); Sylvia M. Phillips)