THE VETCHES, SWEET CLOVERS, AND OTHERS 299 



and not so abundantly supplied with leaves. White 

 sweet clover is a biennial, the first year growing from 1 

 to 3 feet in height, the next year growing much larger and 

 producing numerous white flowers in the form of racemes. 

 The plants bloom all summer long during the second year 

 of their growth and mature an abundance of seed, which 





^^S^^^^Ste?^ 



Fig. 109. — Sweet clover requires an abundance of lime in the soil. 

 The plot at the left was limed before seeding. Both plots were seeded 

 at the same time. 



closely resembles that of alfalfa. The root system is 

 similar in structure and extent to that of alfalfa. During 

 the first year, the tap root is enlarged by the storing 

 of reserve plant food for starting the second year's growth. 

 Nodules are produced on the roots in abimdance by the 

 same variety of bacteria that live on the roots of alfalfa. 

 301. Distribution and adaptation. — Sweet clover is 

 now found in almost all parts of the civilized world. 



