394 GENERAL MORPHOLOGY OF PLANTS 



are usually classed under two heads, as winter wheat and spring 

 wheat. Winter wheat is sown in late summer or early autumn. 

 The cool weather of autumn checks the rapid growth and causes 

 it to " stool," i.e., to throw out numerous branches or " suckers," 

 while the stalks do not become tall. It is very hardy in the 

 young stages and withstands the cold winter, though open win- 

 ters with alternate thawing and freezing often cause it to 

 " heave," so that it dies because the roots are lifted out of the 

 ground. The spring wheats are sown in early spring, but they do 

 well only in the extreme northern latitudes of the temperate 

 region. When grown in the middle temperate regions spring 

 wheat is an uncertain crop, and it is necessary to obtain seed 

 from wheat grown in northern latitudes to obtain the best results. 

 For example, much of the seed spring wheat for the ! Northern 

 States is grown in Canada. When spring wheat can be sown 

 early and the spring season is cold, an opportunity is given for 

 the plants to stool and make a vigorous and stocky growth. While 

 wheat is grown successfully throughout the Northern States and 

 Canada, the great wheat section is in some of the Northwestern 

 States and in Manitoba, though as high yields per acre are 

 obtained in New York as in the great wheat-growing sections. 

 The annual production in the United States amounts to from 

 $300,000,000 to $500,000,000. 



The " hard " wheats, i.e., those with a hard grain, have a 

 greater nitrogen content than the " soft " or starchy wheats, and 

 thus are more nutritious. The hard wheats are better for mak- 

 ing bread, rolls, etc., because the " dough " rises better than that 

 made from the soft wheats. The soft wheats are better for cakes 

 and for pastry. Millers, however, often mix soft wheat with the 

 hard because the latter is more expensive. The spring wheats 

 grown in Canada, Minnesota, Dakota, and other places in the 

 northwest, where there is a low rainfall and consequently drier 

 climate, are chiefly hard wheats, and yield the best flour. In 

 some sections winter wheat is not grown, or is grown to a much 

 less extent because of the severe winters with little snow and 

 high wind. Some winter wheats are, however, hard wheats; 



