43 O BOTANY OF CROP PLANTS 



It has become naturalized in many parts of the United States, 

 occurring in fields and waste places. Common vetch is 

 sown either as a winter or spring annual. If the winters are 

 severe it is planted in the spring. This is the practice in the 

 Northern States. However, in the south, where the winters 

 are mild, it is planted in the fall. It is adapted to a hght 

 soil. It is intolerant of a poorly drained soil. The poorer 

 soils of the East, deficient in hme, will support a fair crop. 

 There are numerous varieties of the common vetch. Spring 

 and winter varieties are recognized. The white or pearl vetch 

 has white flowers and seeds. 



Uses. — Common vetch is grown in the old country, and to 

 an increasing extent in United States, as a hay crop. When 

 grown for this purpose it should be cut when in bloom. The 

 seeds are sometimes made into a flour. The species is also 

 being recommended as a cover crop for orchards, and as a 

 green manure. 



VICIA VILLOSA (Hairy, Hungarian, Russian, Siberian, or Villous Vetch) 



Hairy vetch (Fig. 182) is an annual or biennial, hairy plant 

 naturally suited to cool temperate regions. The plants may 

 grow to a length of 12 feet or more, but seldom to any consid- 

 erable height on account of the weak stems. There is an ex- 

 tensive and deep root system which in the early stages of 

 growth, particularly, constitutes a large proportion of the total 

 weight of the plant. There are five to eight pairs of leaflets, 

 and many (about thirty) violet-blue, rarely white, flowers in 

 one-sided racemes. Cross-fertiHzation is necessary for the 

 normal production of seeds. Bees are chief agents in the 

 dissemination of pollen. The pods are smooth, pale in color, 

 and contain two to eight small, globular black seeds. The 

 cotyledons remain underground at germination, as is the 

 case in the common garden and field pea. Hairy vetch is a 



