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TEXTBOOK OF BOTANY 



of the world. The straw of wheat, rye, and rice is used in 

 hat-making, for mats and ropes, for thatching, and in a 

 variety of other ways. With the cereals should be men- 

 tioned the sorghums, numerous varieties of which have been 

 under cultivation for many centuries. The kernels of sor- 

 ghum are used as food for man and for animals ; the stalks 

 are used as fodder ; and the sweet juice of some varieties is 



FIG. 172. A field of rice. 



a source of sirup and sugar. Broom corn, whose stem-ends 

 and branched flower-stalks are used in the United States 

 for brushes and brooms, is a variety of sorghum. 



333. Other Starch-producing Plants. Aside from the 

 cereal grains, the most important starchy food is the tuber 

 of the potato. The potato plant is a native of America, 

 probably of South America, but is now cultivated throughout 

 a large part of the civilized world. Starch is extracted on a 

 large scale from many plants by grinding the part of the 

 plant which contains it and then washing with water. The 



