GENERA OF GRASSES OF TIIK TXITFJ) 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, chicken 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 drumm-ondii Nees, A. sorghum drummondii Hack.). 

 A recently introduced variety, IIolcus 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 (IIolcus sorghum exiguus 

 (Forsk.) Hitchc., IIolcus 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, IT. S. I'epl. Aj;r. f Bur. Tl. Ind. 

 Bull. 175. 1910. 



