ALFALFA ROOTS 387 



or purple. Generally, however,, the variegated flowers constitute 

 only a small per cent, ranging ordinarily from about one to ten 

 per cent. The rest of the flowers are indistinguishable from those 

 of ordinary alfalfa. The oldest cultivated form of variegated alfalfa 

 is known as Sand Lucern in Europe. It is highly probable that all 

 the variegated or " hardy " alfalfas come from Sand Lucern, as it is 

 known that the original seed of all of them was brought from central 

 Germany, where Sand Lucern is cultivated. They are all similar in 

 appearance, but undoubtedly acclimation has given some slight dif- 

 ference in hardiness and yield. These alfalfas are all much more 

 winter-resistant than the common blue alfalfa, and are coming to be 

 known on the market as " hardy " alfalfas. 



Yellow- flowered or Siberian alfalfa is of little agricultural value. 

 It is a native plant found growing throughout Siberia, and is said to 

 be an important part of the native herbage. Yellow alfalfa is rather 

 prostrate in habits of growth, and has underground rhizomes. It 

 usually produces but one crop a year. We have most interest in this 

 plant because of its great hardiness and the possibility of hybridizing 

 it with other alfalfas to secure hardy strains. The variegated 

 alfalfas, which are supposed to have originated from one of its 

 hybrids, show some tendency to partake of the qualities of Siberian 

 alfalfa, in having variegated flowers, a slight tendency to prostrate 

 stems, and the occasional production of rhizomes. 



Alfalfa Roots. Alfalfa probably sends its roots deeper than any 

 other cultivated plant. In ordinary soil, where grasses would root 

 one to two feet deep, the cereals or red clover four to five feet deep, 

 alfalfa usually penetrates eight to ten feet. On some of the soils in 

 the western States, that are uniform and to a great depth, alfalfa 

 roots often penetrate twenty to thirty feet. 



The typical alfalfa plant in loose soil has a straight tap root which 

 may be from one to two inches in diameter at the top. Small lateral 

 roots are given off in large numbers. However, the root is greatly 

 modified by the character of the soil. If this straight tap root finds 

 a stratum of hard subsoil, it is usually broken up into a much- 

 branched root. Alfalfa grown on hard, compact soil usually develops 

 a series of large branch roots rather than tap roots. 



Certain forms of alfalfa have a tendency to produce more 



