ANDROPOGON SORGHUM 1 97 



Key to the Principal Groups of Sorghum' 



Pith juicy. 

 Juice abundant and very sweet. 



Internodes elongated; sheaths scarcely overlapping; leaves 12 to 15 (ex- 

 cept in Aniber varieties); spikelets elliptic-oval to obovate, 2.5 to 3.5 

 millimeters wide; seeds reddish brown, Sorgo. 

 Juice scanty, slightly sweet to subacid. 



Internodes short; sheaths strongly overlapping; leaves 12 to 15; peduncles 

 erect; panicles cylindrical; spikelets obovate, 3 to 4 millimeters wide: 

 lemmas awnless, Kafir. 

 Internodes medium; sheaths scarcely overlapping; leaves 8 to 11; ped- 

 uncles mostly inclined, often recurved; panicles ovate; spikelets broad- 

 ly obovate, 4.5 to 6 millimeters wide; lemmas awned, Milo. 

 Pith dry. 



Panicle lax, 2.5 to 7 decimeters long; peduncles erect; spikelets elliptic- 

 oval or obovate, 2.5 to 3.5 millimeters wide; lemmas awned. 

 Panicle 4 to 7 decimeters long; rachis less than one-fifth as long as 

 the panicle. 

 Panicle umbelliform, the branches greatly elongated, the tips droop- 

 ing; seeds reddish, included, Broom Corn. 

 Panicle 2.5 to 4 decimeters long; rachis more than two-thirds as long 

 as the panicle. 

 Panicle conical, the branches strongly drooping; glumes at maturity 



spreading and involute; seeds white or somewhat buff, Shallu. 

 Panicle oval or obovate, the branches spreading; glumes at maturity 

 appressed, not involute; seeds white, brown, or reddish, KowUang. 

 Panicle compact, i to 2.5 decimeters long; peduncles erect or recurved; 

 rachis more than two-thirds as long as the panicle. 

 Spikelets elliptic-oval or obovate, 2.5 to 3.5 millimeters wide; lemmas 



awned, Kowliang. 

 Spikelets broadly obovate, 4.3 to 6 millimeters wide. 



Glumes gray or greenish, not wrinkled; densely pubescent; lemmas 



awned or awnless; seeds strongly flattened, Durra. 

 Glumes deep brown or black, transversely wrinkled; thinly pubescent; 

 lemmas awned; seeds slightly flattened, Milo. 



Origin of Sorghums. — The wild form from which our culti- 

 vated sorghums have been derived is Andropogon halepensis 

 (Johnson grass) . This species is native to tropical and sub- 

 tropical parts of the Old World. The view is now quite 



' Taken from Ball. 



