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TEXTBOOK OF BOTANY 



In the eastern hemisphere the principal centers in which the basic 

 crop plants originated are certain parts of central Asia, Asia Minor, 

 central and southern China, northern India and perhaps Ethiopia: the 

 regions in which the earliest civilizations of Eurasia later became most 

 highly developed. Among the cultivated plants on which these early 

 civilizations of Eurasia depended were the cereals (wheat, barley, rye, 

 rice, millet, oats, sorghum), soybeans, and several common vegetables 

 and edible fruits. Most of the cultivated forage crops (clo\'ers and 

 grasses) also originated in the eastern hemisphere (Fig. 199). 



Fig. 199. Forage crop — red clover and timothy. 



Civilization in the past depended upon an unfailing supply of plants 

 as the primary source of food just as it does today. During his long 

 existence upon the earth as a primitive nomad, early man depended 

 upon plants in the wild state. Furthennore, his migrations were condi- 

 tioned by the abundance, or the scarcity, of wild plants. The kinds of 

 wild plants used by prehistoric tribes in all parts of the globe are num- 

 bered in the thousands. The Indians who lived in what is now the 

 United States and Canada used as a source of food more than 1000 

 species of plants, only a few of which were ever cultivated ( Fig. 200 ) . 



