396 FORAGE PLANTS AND THEIR CULTURE 



mass of basal leaves. From the axils of each of these, a 

 secondary leafy aerial branch may arise, and these con- 

 stitute the larger visible portion of the plants. Each sec- 

 ondary branch is terminated by a head of flowers, but 

 commonly bears also tertiary branches each terminated 

 by a head of flowers. One shoot may thus bear as high 

 as 14 heads of flowers. 



The height of the secondary branches varies with the 

 fertility of the soil, but they seldom exceed 30 inches under 

 field conditions. The number is usually from 10 to 20, 

 but as many as 76 have been found on a single plant. 

 After cutting, the branches die back as far as the lowest 

 internodes. 



In winter the hibernating shoots lie close to the ground. 



Werner found that a well-grown plant with 108 leaves 

 had a surface area of 712 square centimeters. Von Gahren 

 in a similar examination found 875 square centimeters. 



468. Proportion of roots to shoots. Several investi- 

 gators have determined the relative proportion of the 

 different parts of the clover plant. 



At the Arkansas Experiment Station single plants 

 showed an average dry weight of two ounces for the 

 tops and 2J ounces for the roots. Smith in Michigan 

 examined plants of red clover at the end of September. 

 Those sown the previous spring had 4.625 pounds of tops 

 and .75 pound of roots, while those sown the year before 

 in June had .1.5 pounds of tops to 1.44 pounds of roots, 

 in each case weighed when fresh. King in Wisconsin 

 estimated the green weight of the tops to an acre at 

 12,486 pounds and of the roots at 3120 pounds. The 

 data used for the estimates were obtained by driving 

 down a cylinder 12 inches in diameter and 30 inches 

 long. Snyder in Minnesota estimated that an acre field 



