FIBER-PRODUCING PLANTS 



349 



are known and cultivated, but the bulk of the world's supply 

 comes from two species, known as upland cotton and Sea Island 

 cotton. Since all cottons are of tropical origin — India, South 

 and Central Americas, and the West Indies — they are grown 

 successfully only in regions of high temperature and long growing 

 season. It has long been the chief crop of the southern United 

 States, which produces over one-half of the world's supply, 

 followed by India, China, and Egypt. Cotton grows best on a 

 deep fertile soil, but some varieties will do well in less favorable 



Fig. 233. — Cotton plants produce large white flowers and fruits with a fibrous 

 covering to the seeds; A and B, the fruit; C, the seed. 



soils if the moisture content is suitable. In its native state, the 

 cotton plant grows as a perennial shrub or small tree, but when 

 grown as a crop plant it is treated as an annual. Sea Island cot- 

 ton, so called because Columbus found it growing in the West 

 Indies, has the longest fiber, but is more exacting in requirements 

 than upland cotton. American production of this variety centers 

 in the coastal regions of South Carolina, Georgia, and Florida. 

 Upland cotton, which makes up 99 % of the United States cotton 

 crop, probably originated in Central America. Its fibers are 

 shorter, but it is easily cultivated and gives a high yield in the 

 southern region extending from Texas to the Atlantic coast. 



