26 BULLETIN 1087, IT. S. DEPARTMENT OF AGRICULTURE. 
plants have very broad, deep-set crowns, well-developed rhizomes, 
and dense root systems. Taproots are either absent or very indis- 
tinct. The decumbent form is intermediate between the other two 
forms. The taproots are indistinct, short, and rapidly tapering. This 
strain had the most extensive root systems of all the alfalfas studied. 
A comparison of the different kinds of alfalfa reveals striking 
differences between certain varieties and strains. There are out- 
standing differences between the root systems of southern-grown 
common and yellow-flowered alfalfas in the prominence of the tap- 
roots, the development of branch roots, the number and development 
of rhizomes, and in the number and place of most profuse produc- 
tion of fibrous roots. Between man}^ plants of common alfalfa, es- 
pecially of the less upright forms, and many plants of the Turkestan 
and Grimm alfalfas, however, differences are not great, and it is 
often impossible to determine by their root systems the groups to 
which these plants belong. In brief, the root systems of the least 
hardy forms of purple-flowered alfalfa may be distinguished from 
the most hardy hybrid and yellow-flowered alfalfas with accuracy, 
but the intermediate forms are not sufficiently distinct to be distin- 
guishable from one another or invariably from some forms of the 
nonhardy or yellow-flowered alfalfas, 
