What is "andropogon sorghum"

Andropogon \An`dro*po"gon\, n. [NL.; Gr. 'anh`r, 'andro`s, man + pw`gwn the beard.] (Bot.) A very large and important genus of grasses, found in nearly all parts of the world. It includes the lemon grass of Ceylon and the beard grass, or broom sedge, of the United States. The principal subgenus is Sorghum, including Andropogon sorghum and Andropogon halepensis, from which have been derived the Chinese sugar cane, the Johnson grass, the Aleppo grass, the broom corn, and the durra, or Indian millet. Several East Indian species, as Andropogon nardus and Andropogon sch[oe]nanthus, yield fragrant oils, used in perfumery.