ALFALFA ROOT STUDIES. 



21 



YELLOW-FLOWERED ALFALFA. 



While several introductions of yellow-flowered alfalfa {Medicago 

 falcata) have been made since 1897, none of them is of commercial 

 importance. As a whole, they are characterized by many branch 

 roots, which taper so gradually that they are often as large at a 

 distance of 2 or 3 feet as they are at the point of origin. They 

 usually extend to a greater depth than the taproot — where it is pres- 

 ent. Fibrous roots are abundant, especially near the surface. Crown 

 branches and rhizomes are small and numerous. Based upon man- 

 ner of growth, these alfalfas may be divided into three general 

 classes: (1) Erect, with narroAv crowns, upright stems, and root 

 system, like Medicago sativa; (2) prostrate, with broad, deep-set 

 crowns, prostrate stems, and a much-branched root system; and (3) 



Fig. 15. 



-Root systems of plants of yellow-flowered alfalfa (Medicago falcata), the 

 growth of two seasons. 



decumbent, intermediate between Nos. 1 and 2 as to root system and 

 general habit of growth. At Redfield the roots of the yellow- 

 flowered alfalfa seldom reach a depth greater than 5 feet, while 

 I Grimm alfalfa, grown under similar conditions, attains a depth of 

 10 feet.« 



Erect yellow-flowered alfalfaJ — The erect form of Medicago 



fcdcata is distinguished from the other types of the species by the 



shape of the crown and the prominence of the taproot, which is rela- 



I lively small but quite as distinct as that of the Grimm alfalfa. The 



I branch roots are more numerous, smaller, and more slowly tapering. 



' Frank N. Meyer reports roots of large size growing in open sandy soils on the banks 

 of the Tom River near Tomsk, Siberia. Some plants were found with roots fully 2 inches 

 in diameter at the crown and more than 1 inch in diameter at a depth of 14 feet. A 

 few of the roots were found to extend to a depth of 33 feet. 



^ S. P. I. Xo. 20721 (Medicago falcata), from Samara Province, Russia, as found wild. 

 (See S. P. I. No. 20726.) 



