64 STUDIES OF TREES 



In the Oc'c'iilental, the seed balls are generally solitary and 

 very rarely in pairs. 



GRAY OR WHITE BIRCH {Betida popuUfolia) 



Distinguishing characters: The dull-white color of 

 the bark on the trunk and the dark triangular patches below 

 the insei'tion of the branches distinguish this tree; see Fig. 

 50. The bark of the young trunks and branches is red- 

 dish-brosvn in color and glossy. The bark adheres closely 

 to the trunk of the tree and does not peel in loose, shaggy 

 strips, as in the case of the yellow or golden birch. It is 

 marked by small raised horizontal lines which are the 

 lenticels or l)reathing pores. These lenticels are char- 

 acteristic of all birch and cherry trees. In addition to the 

 distinction in the color of the bark, an important char- 

 acter which distinguishes the gray birch from all other 

 species of birch, is found in the terminal twigs, which are 

 rough to the touch. 



Form and size: A small tree. Frequently grows in 

 clumps. 



Range: Eastern United States. 



Soil and location: The gray birch does best in a deep, 

 rich soil, l)ut will also grow in poor soils. 



Enemies : The bronze-birch borer, a wood-destroying 

 insect, and Polyporus betulinus, a fungus, are its chief 

 enemies. 



Value for planting: Its graceful habit and attractive 

 bark gives the tree an important place in ornamental plant- 

 ing. It may be used to advantage with evergreens, and pro- 

 duces a charming effect when planted by itself in clumps. 



