CLASSIFICATION AND CHOICE OF FIELD CROPS g 



15. Fiber Plants. — The principal fiber plants of the United 

 States are cotton, liax and hemp. In this country, however, 

 flax is mostly grown for its seeds. The cotton plant is by far 

 the most important fiber plant in the United States and is 

 becoming increasingly the most important source of fiber either 

 vegetable or animal m the world. Ramie, jute and sisal are 

 also sources of fiber. 



16. Stimulants. — Tobacco is of American origin and has 

 been during the whole history of the United States an important 

 industry and has constituted an important article of commerce. 

 The tea plant is now being grown in a small way in South 

 Carolina and, perhaps, elsewhere. Except in Porto Rico, 

 Hawaii and other outlying possessions coffee has not been 

 raised with commercial success. 



17. Medicinal and Aromatic Plants. — Have not been culti- 

 vated largely. The following include the more important ones : 

 mustard, mint (three species), tansy, pyrethrum (buhach), 

 wormwood, valerian and ginseng. 



18. Miscellaneous Crops. — Among the cultivated plants which 



are not included in the foregoing classification are broom com, 

 castor bean, hops, onions, teasel, taro, sunflower seeds, willows 

 and pampa plumes. 



19. The Staple Crops of the United States. — Are grass, includ- 

 ing certain legumes, maize, wheat, oats and cotton. There has 

 been a rapid increase in the cultivated acreage of the country 

 and some changes in the proportion given to different crops, 

 but there is little reason to believe that the time will soon come 

 when these will not be the leading crops, at least so far as acre^ 

 age is concerned. Almost every crop now grown on the farms 

 of the United States had been grown to some extent before the 

 Revolutionary War. Improvements in methods of culture, har- 

 vesting or in machinery' for utilizing the crop have brought some 

 :rops into greater relative importance. This has been notice- 



