IMPORTANCE OF CLOVERS 335 



claimed by some botanists to be a perennial, but ordinarily 

 it is a biennial, as it seldom lives more than two years on 

 account of numerous insects and diseases which attack it. 



Numerous leafy stems are produced from a crown. 

 These reach a height of from 1 foot to 2 feet, depending on the 

 rainfall and the soil. Usually the taller plants do not stand 

 erect, so that the crop seldom appears to be more than 18 

 inches high. The leaflets usually have a pale spot in the 

 center. The flowers are borne in dense heads, which often 

 contain one hundred or more individual flowers. They are 

 similar in shape to pea flowers, but much smaller, and have 

 a long tube. The length of the flower is about half an inch, 

 and the width only about one sixteenth of an inch. The pods 

 are small and membraneous, enclosing the kidney-shaped 

 seeds, which are about one twelfth of an inch long. The 

 seeds vary in color from yellow to purple. 



444. Importance of the Crop. According to the Census 

 report, there were 21,979,000 acres devoted to the production 

 of clover and mixed clover and timothy in the United States 

 in 1909. Only four of our farm crops occupied a larger area, 

 these being corn, wheat, oats, and cotton. Of this area, 

 however, only 2,443,000 acres were in clover alone, the 

 remainder being used for the production of mixed hay. 

 With the exception of small areas in other states, clover pro- 

 duction is confined to the North Atlantic and North Central 

 states, the region extending from Maine to Virginia and 

 westward to the eastern portion of the Dakotas, Nebraska, 

 and Kansas. There are also considerable areas devoted to 

 clover in western Oregon and western Washmgton. Alfalfa 

 largely replaces clover in the Rocky Mountain states, though 

 occasionally large crops of clover are grown in valleys where 

 alfalfa does not thrive. 



The principal states in the production of clover and 

 mixed clover and timothy are Iowa, with three and one 

 half million acres; New York with three miUion acres; Michi- 



