GENERA OF GRASSES OF THE UNITED STATES. 267 
Holcus sorghum L. (Andropogon sorghum Brot. ; Sorghum vul- 
gare Pers.) has been cultivated from prehistoric times 1 for the seed, 
which has been used for food, for the sweet juice, and for forage. In 
the United States it is cultivated under the general name of sorghum 
or sorgo. There are many races and varieties, the chief of which are 
sorgo, kafir, milo, broom corn, shallu, kaoliang, and durra. Sorgo 
includes the varieties with sAveet juice, these varieties often being 
known collectively as saccharine sorghums. 
In this country, sorgo is cultivated, chiefly in the region from Kan- 
sas to North Carolina, for the juice which is made into sirup and 
for foliage which is used for fodder in the Southern States, especially 
in the region from Kansas to Texas, where it is often called " cane." 
The other races of sorghum are often classed together as non- 
saccharine sorghums. The large panicles of one race, broom corn, 
grown especially in Illinois, furnish the material for brooms. The 
other races are used for forage or for the seed, which is used for 
feed. Kafir, milo, and a recently introduced variety, feterita, are 
of especial value in the southern part of the Great Plains and other 
semiarid regions where dry-land farming is practiced. Kafir, or 
Kafir corn, is a rather low form with compact cylindric heads and 
awnless spikelets. Milo, or milo maize, is a usually taller form, with 
ovate heads, a straight or recurved peduncle, awned spikelets, and 
larger seeds. Durra differs from milo in having densely pubescent 
grayish or greenish glumes (instead of brown or black and slightly 
pubescent), and strongly flattened seeds. Some of these forms are 
called Egyptian corn, chkken corn, and Jerusalem corn. The name 
chicken corn should be restricted to a variety spontaneous in Louisi- 
ana and Mississippi (Holcus sorghum drummondii (Nees) Hitchc, 
Andropogon drummondii Nees, A, sorghum drummondii Hack.). 
A recently introduced variety, Holcus sorghum sudanensis (Piper) 
Hitchc. (Andropogon sorghum sudanensis Piper), is now extensively 
cultivated for hay in the semiarid regions under the name of Sudan 
grass. This is a rather slender annual, 6 to 9 feet tall, the panicle 
open and spreading. The absence of rhizomes shows its affinity to 
sorgo. Tunis grass is an allied variety (Holcus sorghum exiguus 
(Forsk.) Hitchc, Holcus exiguus Forsk., Andropogon sorghum ex- 
iguus Piper) that has been tried in our Southern States. 
The second species of Holcus found in the United States is H. 
halepensis L. (fig. 162), known as Johnson grass. This is a perennial 
with stout creeping rhizomes. The panicle is open and spreading, 
the spikelets awned or awnless. Johnson grass is not so tall as the 
open-panicled forms of sorghum, being usually 3 to 5 feet tall, and 
1 For a history and classification of sorghum, see Ball, U. S. Dept. Agr., Bur. PI: Ind. 
Bull. 175. 1910. 
