POLYGONACEjE 



293 



more starchy than that of wheat, oats, barley, rye and corn, 

 and the fat content is lower. Consequently, buckwheat 

 flour is low in percentage of protein and fat. The embryo 

 ("germ"), however, has an abundance of fat and protein, and 

 for this reason "middlings," which contain the embryo, are a 

 valued stock food. In a cross-section of the fruit (Fig. 

 115, C), the embryo has the form of the letter S, and reaches 

 from one of the three angles of the seed to another. 



-testa 



-nucellus 



-aleurone 



- — j/arc/iy 

 endosperm 



Fig. 116.- 



-Common buckwheat (Fagopyrum vulgare). 

 seed. (After Stevens.) 



Section of mature 



Geographical. — Common buckwheat has been cultivated 

 in China for 1,000 years. It was introduced into Europe 

 during the middle ages. It was brought into this country 

 by the early settlers. It has escaped from cultivation in 

 North America, and is now common throughout northern 

 United States and Canada. 



Other Species. — There are two other species of Fagopyrum, 

 one of which, -F. tataricum, at least, has been cultivated to a 

 slight extent in this country, and is also an occasional escape 

 from cultivation. Tatary buckwheat is distinguished from 

 the common form by the simple racemes, its rough hull, and 

 the wavy fruit angles. It is cultivated where a hardy sort is 



