ALFALFA 321 



root maintains its tap character, the branches being, usually 

 much smaller than the main root which may become one 

 inch in diameter, but rarely exceeds half this thickness. 

 The crown which is just beneath the surface of the soil, 

 becomes much branched and in old plants may give rise 

 to as many as 100 ascending leafy branches. True rhi- 

 zomes rarely occur in common alfalfa, though the crown 

 may become branched 2 or 3 inches below the surface. 



The root system of yellow or sickle alfalfa differs 

 markedly from common alfalfa in producing abundant 

 rhizomes. Not only this, but in some cases aerial branches 

 arise directly from horizontal roots. Such roots may 

 extend six feet or more, giving rise at intervals to aerial 

 shoots. 



Variegated alfalfa, in accord with its hybrid origin, 

 possesses roots with intermediate characters. In many 

 cases the roots promptly divide into several branches, 

 and rootstock development also occurs in a large propor- 

 tion of the plants. On account of this root branching, 

 variegated alfalfa is less subject to heaving, and the deep 

 crown and rootstocks protect the plant against severe 

 winter cold. 



Oliver has developed hybrids that under greenhouse 

 conditions produce rootstocks luxuriantly, and suggests 

 that such varieties will be especially valuable for pastur- 

 age. 



Alfalfa will not thrive in water-logged soil, or, in the 

 language of the farmer, will not withstand " wet feet." 

 The probable reason for this is more likely due to insuffi- 

 cient air than to superabundance of moisture. Alfalfa 

 will rarely succeed unless the water table is more than a 

 foot from the surface. 



On account of the deep roots, a friable subsoil is best 



