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. . KAFirR. 
cc. Panicles ovate; peduncle mostly inclined, 
often recurved; spikelets 4.5 to 6 mm. 
wide: lemmas Aawhed ..34 6.625 6a es ote Mino. 
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-CorRN. 
cc. Rachis more than two-thirds as long as 
the panicle. 
D. Panicle conical, the branches strongly 
RON eu ue tn eet chars cas x eee ae SHALLU. 
pp. Panicle oval or obovate, the branches 
BEES HN 6 erasure ieee 6 KowLiaNG. 
BB. Panicle compact, 10 to 25 cm. long. 
c. Spikelets elliptic-oval or obovate, 2.5 to 
ay HAR es Go bthe aan’ sie KOWLIANG. 
cc. Spikelets broadly obovate, 4.5 to 6 mm. 
wide. 
p. Glumes gray or greenish, not wrinkled, 
densely pubescent; seeds strongly 
PRL DONEC adi Mote via Ciirs bs Gabe aie aati DurRRA. 
DD. Glumes deep brown or black, trans- 
versely wrinkled, thinly pubescent; 
seeds slightly fluttenadl aos °i.isoxaeaets 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 
