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 

 sativa, are of agricultural importance in this country. 



296. Hairy vetch. — This species is also known as 

 sand vetch and winter vetch. It is a ^vinter annual, wAh 

 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 I 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 



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