Man. Fl. North US 71 (1901); Gen. Gram.: 341 (1986).- Type-species: Sorghastrum avenaceum (Michaux) Nash (= S. nutans).
Sorghum sect. Sorghastrum Stapf, FTA 9: 111 (1917).
Description:
* Annuals or perennials. Leaves linear; ligule scarious.
* Inflorescence a terminal panicle; primary branches branched, flexuous, bearibf short fragile racemes. Racemes sometimes reduced into triads; internodes and pedicels filiform, ciliate.
* Sessile spikelet dorsally compressed; callus obtuse to pungent, bearded. Lower glume coriaceous, convex and rounded flanks, keeled near the tip. Lower lemma barren, hyaline; upper lemma hyaline, bi-dentate with a straight or geniculate awn from the sinus, rarely awnless. Pedicelled spikelet absent, its pedicel slightly shorter than the sessile spikelet.
A tropical American and African genus with about 16 species of savannah woodland.