172 A TEXT-BOOK OF GRASSES 



and shining on the exposed parts; staminate spikelets more slender, 

 and slightly longer than the sessile, distinctly nerved, membra- 

 naceous, the pedicel about half as long as the sessile spikelet, ciliate. 

 The staminate spikelets disarticulate early so that the mature fertile 

 spikelets show only the 1 or 2 ciliate pedicels at the back. The whole 

 plant is frequently subject to a disease which produces purple spots 

 on the stem and leaves. This is also observed in Holcus Sorghum. 



211. Classification of the sorghums. — Ball (loc. cit.) 

 classifies the sorghums as follows: 



A. Pith juicy. 



B. Juice abundant and very sweet Sorgo. 



BB. Juice scanty, slightly sweet to subacid. 



c. Panicles cylindrical ; peduncles erect; spike- 

 lets 3 to 4 mm. wide; lemmas awnless. .Kafir. 

 cc. Panicles ovate; peduncle mostly inclined, 

 often recurved; spikelets 4.5 to 6 mm. 



wide; lemmas awned Milo. 



AA. Pith dry. 



B. Panicle lax, 25 to 70 cm. long. . . 



c. Rachis less than one-fifth as long as 

 the panicle; panicle umbelliform, the 



branches greatly elongated Broom-Corn. 



cc. Rachis more than two-thirds as long as 

 the panicle. 

 D. Panicle conical, the branches strongly 



drooping Shallu. 



DD. Panicle oval or obovate, the branches 



spreading Kowliang. 



BB. Panicle compact, 10 to 25 cm. long. 



c. Spikelets elliptic-oval or obovate, 2.5 to 



3.5 mm. wide Kowliang. 



cc. Spikelets broadly obovate, 4.5 to 6 mm. 

 wide. 

 D. Glumes gray or greenish, not wrinkled, 

 densely pubescent; seeds strongly 



flattened Durra. 



DD. Glumes deep brown or black, trans- 

 versely wrinkled, thinly pubescent; 

 seeds sUghtly flattened Milo. 



Sudan-grass resembles Johnson-grass in habit but is 

 an annual, entirely devoid of rootstocks. By Piper it is 

 referred to Sorghum as a variety. Sudan-grass promises 



