216 THE BOOK OF FORESTRY 



THE OAKS 



The oak family is by all means the most important 

 of all the broadleaf genera found in the Northern 

 Hemisphere as over one-third the total cut of hardwoods 

 is supplied by the various oaks. Of the fifty-two species 

 found in the United States five are shrubs; twenty- 

 three of the tree species belong to the white oak group 

 and twenty-four to the black oak group. The dis- 

 tinctive feature of this genus is the fruit an acorn 

 and the length of time it takes to mature this fruit 

 divides the white from the black oak group. In the 

 former the acorn matures in one year, with one minor 

 exception, while with the black oaks two seasons must 

 elapse before the fruit is mature consequently if a tree 

 belongs to the black oak group it will have small acorns 

 on the tree in the winter which will ripen during the 

 next season. 



