52 A TEXT-BOOK OF GRASSES 



and leaves being used for hay or green feed, the remainder 

 being turned under for green manure. When grown on 

 sterile soil it may be necessary to turn under a larger 

 proportion in order to produce humus. (See Farmers' 

 Bulletin No. 318.) 



65. Velvet bean (Stizolobium Deeringianum Bort). 

 This coarse rank-growing vine is similar to the cowpea but 



, gives a much greater growth. The velvet bean is not so 

 1 hardy as the cowpea and is used only in the South. It 

 has given excellent results in Florida. (See Farmers' 

 , Bulletin No. 509, and Bur. PL Ind. Bulletin No. 179). 



66. The vetches are upright or reclining plants with 

 ' tendrils at the ends of the compound leaves. In a general 



way they resemble the garden pea, but the leaflets and 

 flowers are smaller. There are two common kinds of 

 vetch in use in the United States spring vetch (Vicia 

 sativa L.) and hairy vetch (V. villosa Roth). The one 

 ! most grown is the latter, since it better withstands 

 | drought. The vetches are usually sown with grain, the 

 latter supporting the vetch, thus producing a combina- 

 tion that can be harvested with greater ease than can the 

 vetch alone. Vetch may be used as a winter crop in the 

 South or as a summer crop in the North. (See Farmers' 

 Bulletins Nos. 515, 529.) 



67. Crimson clover (Trifolium incarnatum L.). This 

 is a tall clover with long heads of crimson flowers. It is 



rather extensively used in the region from New Jersey to 

 North Carolina. It should be cut when in flower. If cut 

 later the fuzzy hairs around the head prove troublesome, 

 especially to horses. (See Farmers' Bulletin No. 579.) 



Field pea (Pisum arvense L.). The field pea, resembling 



I the garden pea in habit, is much used in Canada and our 



more northern states. The field pea requires a cool, 



