DESCRIPTION OF TREES. 



159 



most constant attention that it can be grown so as to reach 

 large size. 



EUROPEAN MOUNTAIN ASH (P. aucuparia). Very simi- 

 lar to the last in habit of growth and foliage, but with larger 

 and lighter colored berries. It requires the same treatment 

 to prevent injury from insects as the last species. 



OAK-LEAVED MOUNTAIN ASH (P. a., var. quercifolia)^ 

 Fig. 81. A very interesting form of the last species, of a 



FIG. 81. OAK-LEAVED MOUNTAIN ASH (Pyrus aucuparia 

 quercifolia). 



more compact habit, however, and having leaves somewhat 

 like those of the English oak. Attention must be given 

 this tree to prevent injury from borers. 



HOP-TREE (Ptelia trifoliatd) . This small round-headed 

 tree possesses peculiar beauty of form and dark, rich color 

 of foliage, but its most striking feature is the masses of 



