CHAPTER XVI 



THE VETCHES, SWEET CLOVERS, 

 AND OTHERS 



THERE are several kinds of vetches, but only two, 

 hairy vetch, Vicia villosa, and common vetch, Vicia 

 saliva, are of agricultural importance in this country. 



296. Hairy vetch. This species is also known as 

 sand vetch and winter vetch. It is a winter annual, with 

 long, trailing, vine-like stems, which are not strong enough 

 to grow erect unless supported by other plants. The 

 leaflets are arranged in pairs on a rather long midrib, which 

 terminates in a tendril. The flowers are produced in 

 racemes which grow from the axils of the midribs and are 

 bluish-purple in color. The seed pods, when they ma- 

 ture, are straw colored and from 1 to 2 inches in length 

 and about J inch wide. The seeds are black, round or 

 spherical in shape, and about one-half the size of a pea. 

 The roots are inclined to be fibrous and produce an abun- 

 dance of tubercles, the bacteria in which are active late 

 in the fall and early in the spring, thus making the plant 

 a great nitrogen gatherer. 



297. Adaptation and uses. Hairy vetch is very hardy 

 and is able to withstand severe cold during the winter. 

 It grows well on almost any well-drained soil, but is espe- 

 cially adapted to rather sandy soil. The most common 

 uses are as a cover crop and as a green manure crop for 

 plowing under to improve the soil. As a cover crop, it 



294 



