Plant Industries and Climatic Plant Formations 353 



U. S. Dept. of Agriculture 



Fig. 220. Tobacco, rice, flax, and hemp acreage, igig. The regions in which tobacco is 

 grown are determined by soil characters; each particular tobacco-producing area grows 

 only certain kinds that develop on its soil the desired flavors. Flax is produced in the 

 northern Great Plains region, because the drought and the prolonged illumination favor the 

 production of seed. The necessity for hot growing seasons and inundation of the land for 

 rice production explains why the growing of the crop centers in the areas shown on the map. 



is mostly grown on the limestone soils of Kentucky and Ohio. 

 Cigarette and light smoking tobaccos are grown on rather in- 

 fertile sandy loams on the eastern Coastal Plain. 



Sorghum, used for the manufacture of table syrup and sorghum 

 molasses, is grown in the southern half of the deciduous forest 

 region. It resembles corn in appearance, and the syrup is ob- 

 tained by crushing it and evaporating the juice. In the North its 

 sugar content is lower and its cultivation is not so profitable. Its 

 cultivation is also excluded from soils rich in nitrates, because of 

 the increased amount of bitter substances present under these 

 conditions. As much as 50 million gallons has been produced 

 in one year. 



i The southeastern conifer forest. The greatest plant industry 

 of the Southeast has been the lumbering of the longleaf pine, the 



