ALFALFA ROOT STUDIES. 
17 
The angle which the branch roots form with the taproot is quite 
similar in all the alfalfas studied, with the exception of the yellow 
flowered variety where this angle is somewhat greater. Fibrous 
roots, while more numerous than in Peruvian and Poona alfalfas, 
are relatively sparse and well distributed over the root system, differ- 
ing in this respect from the hardier varieties. (Table 7, column l) 
Rooting rhizomes are fewer and not so well developed as in northern- 
grown common, Turkestan, or Grimm. (Fig. 12.) 
Fig. 12. — Root systems of southern-grown common alfalfa plants, the growth of one 
season. 
Table 7. — Estimates of the prominence of the branch roots and the relative abun- 
dance of fibrous roots in different kinds of alfalfa at Redfield, S. Dak. 
Kind. 
Number 
of plants 
consid- 
ered. 
Promi- 
nence of 
branch 
roots. 
Relative 
abun- 
dance of 
fibrous 
roots. 
Southern-grown common . . . 
Northern-grown common 
Turkestan 
Grimm 
Decumbent yellow flowered . 
Prostrate yellow flowered. . . . 
300 
75 
75 
225 
19 
22 
185 
92 
3 100 
2 85 
92 
97 
97 
98 
<100 
1 Few branch roots; prominent taproots. 
3 Branch roots numerous; taproot indistinct. 
2 Rather sparse. 
4 Very abundant. 
NORTHERN-GROWN COMMON ALFALFA. 
In the United States the hardy strains of common alfalfa are 
largely the result of selective acclimatization, although in many cases 
the presence of a small percentage of Medicago falcata blood has 
contributed to the hardiness of these strains. 
