THE WHEAT GRAIN AND PLANT 



9 



class they belong. Some of the most common and widely used 

 classifications are those based on time of sowing, as spring and 

 winter wheat; on firmness of structure of the grain, as hard 

 and soft; on the products for which they are used, as bread 

 and macaroni wheats; and on the color of the seed, as red 

 and white. As will later be shown, wheat adapts itself to new 

 environments so that any one of these classes may be trans- 

 formed into any other, and as wheat is raised so widely as to 

 embrace practically every kind of environment, these classes 

 grade into each other so imperceptibly that even an expert can 

 hardly determine to which class a certain wheat may belong. 

 An approximate division has, however, been made. Mr. M. A. 



DISTRICTS 

 SOPT 



SEMI-HARD 

 SOUTHERN 

 HARD-SPRING 

 HARD-WINTER 

 DURUM 

 IRRIGATED 



DISTRIBUTION OF WHEAT VARIETIES IN THE UNITED STATES 



Carleton, 1 cerealist of the United States department of agri- 

 culture, has divided the wheat grown in the United States into 

 eight classes, and has shown the distribution of these classes 

 by districts in the accompanying map. 



On the north Atlantic coast is the soft wheat district, south 

 of the Great Lakes the semi-hard district, and south of these 

 two districts is the southern district. The Red river valley is 

 1 U. S. Dept. Agr., Div. Veg. Phys. & Path., Bui. 24. 



