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SUGAR-PRODUCING PLANTS 



217 



ical change, while starches, fats, and proteins must undergo a 

 more complicated series of digestive processes before they are 

 ready to be carried out to the tissues for energy release. The in- 

 habitants of temperate zones now consume most of the world's 

 sugar crop, which is exceeded in value only by such crops as 

 wheat, corn, rice, and potatoes. In spite of the fact that sugar is 

 produced as a storage food in many different plants, our com- 

 mercial supply of this commodity comes from a few plant species 

 — sugar cane, sugar beet, various kinds of sorghum, the sugar 

 maple, and several kinds of palms (fig. 157). 



Cane Sugar 



Sugar cane is not known to exist in the wild state, hence the 

 geographical origin of the plant is in doubt; it may well have 

 originated in southeastern Asia, 

 since as long ago as 327 B.C. 

 this plant constituted an im- 

 portant crop in India. About a 

 thousand years later the grow- 

 ing of this crop had spread to 

 Spain and Portugal, whose sea- 

 faring adventurers were respon- 

 sible for its dissemination to 

 various tropical parts of the 

 New World, the plant having 

 reached the United States — 

 Louisiana — in 1751. About this 

 time the sugar industry was 

 already well established in 

 Cuba, which is sometimes 

 called the "world's sugar bowl" 

 because of its large scale produc- 

 tion of cane sugar. Today this 

 constitutes the principal export crop of tropical regions over large 

 portions of the earth, since sugar cane flourishes in any hot moist 

 climate. The plant itself (fig. 158) is a perennial grass which 

 grows from six to fifteen feet high, with solid stems one to two 

 inches in diameter. It is propagated principally by means of 



Fig. 158. — Sugar cane is a peren- 

 nial grass with solid stems, growing to 

 a height of fifteen feet. 



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