ALFALFA ROOT STUDIES. 
23 
Decumbent yellow -flowered alfalfa? — The decumbent form of yel- 
low-flowered alfalfa is intermediate between the two forms previously 
considered. The type is represented by S. P. I Xo. 33465. The tap- 
roots are indistinct, short and rapidly tapering and slightly smaller 
than the southern-grown common and Grimm varieties, as is shown 
in Table 5. This strain has the most extensive root system of all the 
alfalfas studied. The rhizome development is greater than any of 
the alfalfas except the prostrate yellow-flowered. Fibrous roots are 
relatively abundant. (Table 7, Figs. 9 and 18.) 
Fig. 17. — Root systems of prostrate yellow-flowered alfalfa plants having distinct tap- 
roots, the growth of six seasons. 
Koot proliferation has been observed in Medicago falcata intro- 
ductions from Orenburg, Russia, and Semipalatinsk, Siberia. This 
characteristic has also been observed in some hybrid alfalfas. True 
lateral roots have been found extending parallel to the surface for 
36 inches, at a depth of 4 to 12 inches. At irregular intervals the root 
enlarges to about double its normal diameter. These enlargements 
or swellings send out aerial shoots and may or may not develop fibrous 
roots. (Fig. 19.) 
9 S. P. I. No. 33465 (Medicago falcata), from Semipalatinsk, Siberia ; presented by G. T. 
Miroshnikoff, at the request of Frank X. Meyer. Received Feb. 19. 1912. 
