N. Amer. Fl. 17: 130 (1912).- Type:
Andropogon incompletum J. Presl, Reliq. Haenk. 1: 342 (1830)
var. bipennatum (Hack.) Dávila
Ann. Missouri Bot. Gard. 76: 1171 (1989).- Type: Schweinfurth 2486, Sudan, Grosse Seriba Ghattas (iso- K).
Andropogon bipennatus Hack., Flora 68: 142 (1885);
Sorghum bipennatum (Hack.) Kuntze, Rev. Gen. PI. 2: 791 (1891);
Andropogon nutans Linn. var. africanus Franchet, Bull. Soc. Hist. Autun 8: 329 (1895);
Sorghastrum bipennatum (Hack.) Pilger, Notizbl. Bot. Gard. Berl. 14: 96 (1938).
​Regional description: FTA 9: 144 (1917); Fl. Gabon 5: 146 (1962); FWTA: 468); Ghana grasses: 238, fig. 86 (1977); FTEA: 731 (1982); Gram. Togo: 318 (1983); Gram. Cameroun: 406, fig. 87(1992); Fl. Bénin: 244, fig. (1992); Poac. CI: 484, fig. (1995); Fl. Ethiopia & Eritrea 7: 301, fig (1995); Poac. Niger: 518, fig. (1999);); Fl. Guinea Bissau: 143 (2008); Fl. Guinée: 477 (2009); Pl. Burkina Faso: 113 (2012); Fl. Zambesiaca 10,4:28, fig (2002); Fl. Chad (2013); Pl. Sudan & S Sudan: 146 (2015).
Description:
* Delicate straggling annual of 0.3-1.2 m high. Culms soft, weak and geniculate, often dark purple, branching and with long purple prop-roots from the lower nodes, often leaning on its neighbours; nodes with ring of short white hairs. Leaves drooping downward, flat to partially folded, 10-60 cm long and 3-10 mm broad, glabrous with a prominent midrib and sharply scabrid margins; base rounded with a dark brown collar; ligule a truncate brown membrane of up to 2 mm long; sheath glabrous to slightly hairy, sometimes auriculate. Roots sparse.
* Inflorescence a highly branched, open or contracted panicle of 10-40 cm long. Principal axis weak; branches verticellate, sinuous. Racemes reduced to one sessile spikelet accompanied by two ciliated pedicels of 3-4 mm long. Spikelets shedding easily and falling with the attached pedicels.
* Spikelets plump, ovate, glossy-brown, 4-5 mm long, coriaceous, hirsute with white hairs. Lower glume coriaceous, flattened or slightly rounded; upper glume boat-shaped. Upper lemma hyaline, ciliated margins, shortly 2-teethed with a bigeniculate awn, dark below, 3-4 cm long. Pedicelled spikelts reduced to the pedicel; pedicel shorter than spikelet. Anthers 2.
Distribution West Africa: Guinea Bissau, Guinea, Sierra Leone, Mali, Ivory Coast, Burkina Faso, Ghana, Togo, Benin, Niger, Nigeria, Cameroon, Chad, South Sudan.
Distribution world-wide: Congo, DRC, Ethiopia and C and southern Africa, Tanzania, Latin America.