22 



BULLETIN 1087, U, S. DEPARTMENT OF AGRICULTURE. 



Figure 15 shows roots of one of the most upright, narrow-crowned 

 forms of yellow-flowered alfalfa that has been introduced. Seven oi 

 these plants have distinct taproots and five show a decided branching 



tendency. The branch root; 

 are put forth obliquely anc 

 form a someAvhat greatei. 

 angle with the taproot thai 

 is the case with Grimm an( 

 Turkestan. The crown ii 

 quite similar to that of th(| 

 Grimm except that thi 

 crown branches and rhi' 

 zomes are smaller and mor 

 numerous. Fibrous root! 

 are relatively abundant. 



Prostrate yellow -flowerel 

 alfalfa .^ — The prostrat 

 yellow-flowered alfalfas ar 

 characterized by very broa* 

 deep-set crowns, well-devel 

 oped rhizomes, and dens 

 root systems. Taproots ar, 

 either not apparent or ar 

 very short and indistinc 

 As shown in Table 6, brane 

 roots are somewhat moii 

 numerous than in Medieag: 

 sativa. The angle that tl" 

 branch roots form with th 

 taproot is somewhat greatf; 

 than with purple-flowerej 

 and hybrid alfalfas, 

 large percentage of tl 

 branch roots originate froJ|' 

 the rhizomes, thus sugges 

 ing that the highly deve 

 oped root system is at tl 

 expense of the taproot ar 

 its branches. Khizomes a 

 longer and more branchiij,' 

 than in the common i' 

 variegated alfalfas. Fibrous roots occur in considerable abundam 

 in all parts of the root system. (Figs. 16 and 17.) 



Fig 



16. — Root system of a prostrate yellow-flowered 

 alfalfa plant, the growth of six seasons. 



* The alfalfa considered is S. P. T. No. 20717 {Medicago falcata), from Kharkof Pri- 

 ince, southwestern Russia, a wild form. 



