12 



No. 19. Andropogon contortus Linn. Twisted Beard-grass. 



A stout, leafy perennial, 1 to 3 feet high, aftording excellent grazing when young, 

 but the mature seeds are much dreaded by sheep owners, as by their peculiar 

 structure tbey not only become attached to and injure the wool, but ofteu pene- 

 trate the skin and even the intestines of these animals. The strong rhizomes and 

 tough fibrous roots which this grass has, commend it as a soil binder for river 

 lianks, dams, etc. The awns indicate by their twisting the amount of moisture 

 in the air, and may be used as rain or fair weather indicators. In India this grass 

 is used for thatching. It is a native of tropical and subtropical regions of both 

 liemispheres, extending northward into we.stt'rn Texas, New Mexico, and Arizona. 



No. 20. Andropogon glonieratus 

 (Walt.j B. S. r. Brook-grass. 



A stout perennial, 2 to 4 feet high, 

 with dense, more or less elon- 



^^: 



Fig. 6. — Johnson-gras-s {Andropogon hale- Fig. 7. — Bushy Hlue-stem (Andropogon nutans) : a to/, 

 pensis). details of the spikelet. 



gated, broom-like panicles. It grows in low grounds and marshes from southern 

 New York to Florida, also occurring in Mexico and Lower California. This 

 species is esteemed a valuable pasture grass in the .South. Its stems and 

 leaves when young, are ten<ler and Juicy and are relished by stock of all kinds. 

 Later the stems become tough and woody and are of less value. 



No. 21. Andropogon halepensis (L.) Brot. .Johnson-grass. (Fig. 6.) 

 A stout perennial, with smooth, erect culms, 3 to 6 feet high, and strong, creeping 

 rootstocks. The panicles are expanded during ilowering and are from 6 to 12 

 inches long. It is a native of southern Ilurdjie and the warmer parts of Asia and 

 north<Tii Africa. It was introduced into this country about sixty years ago, and 

 has now become widely distributed ami well known throughout the Southern 



