THE CEREAL FRUITS 



171 



Eight main types of wheat are known today, some comprising 

 dozens of varieties (fig. 103). Longest under cultivation and 

 therefore perhaps the most primitive types are the emmer, ein- 

 korn and spelt wheats characterized by grains which do not 

 separate easily from the husks. Emmer wheat, already noted, 

 is grown in Spain, Italy, Germany and Russia. Einkorn wheat 

 thrives on poor soil, and even though a small plant with low 

 yield, it is valuable in its ability to grow where other wheats find 

 it difficult to survive. It has been used in southern Europe since 

 the Stone Age; in the United States it is grown occasionally for 

 fodder. Spelt wheat is hardy and grows on the poorest soils; 



Fig. 104. — Distribution of acreage devoted to winter wheat (dots) and spring 

 wheat (circles) in 1930. 



it is a Mediterranean variety, being cultivated particularly in 

 Spain. In the United States it is grown to only a slight extent, 

 as a live stock feed. 



The kinds of wheat cultivated in the United States are pre- 

 dominantly derived from the Polish, poulard, club, durum and 

 bread wheat varieties. Polish wheat, recognized by the large 

 papery bracts covering each spikelet, has not proven very satis- 

 factory; the plants attain a considerable size and grow vigorously, 

 but have a low yield of grain. The same is true of the poulard 

 WHEAT varieties, which are more popular in the Mediterranean 

 countries than in the United States. Club wheats are grown in 

 the Rocky Mountain and Pacific coast states, mostly for pastry 

 flour and export. Most of the American crop, however, comes 



