14 



BULLETTX 1087, U. S. DEPAETMEXT OF AGEICULTURE. 



POONA ALFALFA. 



In 1913 the ITnited States Department of A^nculture received 

 seed of a distinct variety of Medicago sativo. from west-central India. 



This alfalfa, wliicli has been given the name of Poona, from its 

 source, has proved to be even less hard}- than the Peruvian variety. 

 Poona alfalfa seeded at Eedfield in 1915 suffered complete mortality 

 the following winter, while Peruvian seeded under the same condi- 

 tions had a small percentage of surs'ival. The variety is charac- 

 terized by narrow, upright crowns, few crown branches, and very 

 few, if any, rooting rhizomes. It differs from most other varieties 

 in tlie almost entire absence of branch roots on the upper portion of 

 the taproot. At a depth of 8 to 12 inches, however, branch roots are 



Fig. 9. — Root systems of decumbent plants of yellow-flowered alfalfa (iledicar/o falcata). 

 Xo winterklUiiig and very little injury occurred in this alfalfa during the 6-year 

 period from 1915 to 1920, inclusive. 



relatively profuse. Fibrous roots are sparse and rather uniformly 

 distributed over the root system. The differences between roots of 

 one season's growth of this and other varieties and strains are shown 

 by a comparison of Figure 11 with Figures 10 and 12 to 14, inclusive. 



COMMON ALFALFAS. 



The common alfalfas include the purple-flowered strains generally 

 grown throughout the western United States. It is believed that 

 practically all of them have a common lineage, being descended from 

 stock introduced into California during the early history of that 

 State. For convenience they may be arbitrarily placed in two 

 groups: Southern-grown common and northern-grown common. 



SOUTHEBX-GEOWN COMMON ALFALFA. 



HaA-ing comparatively small, upright crowns and pronoimced tap- 

 roots, southern-grown common alfalfa also has relatively few branch 



