LEGUMTNOS.E 449 



In s[)ile of its relatively high water requirement, alfalfa 

 is able to withstand drought. This is due to its deep root 

 system which draws upon the water in the lower strata of soil. 



Alfalfa cannot withstand alkali, and sufTers if soil drainage 

 is not good. The [)lant rec[uires lime in the soil. The soil 

 type has considerable influence u[)on the form of the root 

 system. A hard compact soil causes a more or less branch- 

 ing root system, while in a loose soil the tap root system is 

 typicall}' de\-el()[)ed. 



Uses and Production.- -Alfalfa is the most imi)()rtant hay 

 crop ''n the Western States. The total number of acres in 

 allall'a in the United States, 1909, was 4,707, £46; of this 

 number, the Western States furnished 4,523,513 acres. 

 The live leading States, 1909, named in the order of their 

 alfalfa [)r()duction were Kansas, Nebraska, Colorado, Cali- 

 fornia and Idaho. 



MEDICAGO LUPULINA (Hop Clover, Black Medic, Yellow Trefoil) 



This plant is usually annual, sometimes perennial. The 

 stems are four-angled, pubescent, and branched at the base, 

 the branches being decumbent and spreading. The petioled 

 leaves have small obo\'ate, oval or orbicular, denticulate or 

 crenulate leallets. The jlowers are small, yellow, in den.se, 

 oblong or cylindrical heads. The pods are black, curved, 

 strongly veined, and one-seeded. 



The plant is a native of Eurasia. It is now found through- 

 out the greater part of the United States and other temperate 

 regions where it occurs in fields and waste places.' It is 

 sometimes [)lanted on poor soil, and has some promise as 

 a green manure. 



MEDICAGO ARABICA (Spotted Bur Clover) 



This is a smooth annual j)lanL with procumbent stems. 

 The Iciilcls have a dark purpK' spot in the center. The pods 



