Description of Trees 183 



able pyramidal trees. When not injured by the above 

 pests, they grow* very rapidly and reach large size. (See 

 chapter on Insects and Diseases.) 



White-leaved European Linden (r. tomentosa). A vigor- 

 ous tree with a more rounded head than the last and with 

 leaves dark green above and silvery white beneath. Sub- 

 ject to the same pests as the last. 



American Mountain Ash (Sorbus americana). One of 

 the most beautiful native small trees often found growing 

 on our mountains. Its large cymose panicles of white flowers 

 are very beautiful, and there is scarcely anything more beauti- 

 ful than the large clusters of dark red fruit in the autumn 

 and early winter. It is so seriously injured by the apple- 

 borer, however, that it is only by the most constant atten- 

 tion that it can be grown so as to reach large size. 



European Mountain Ash (S. 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 ($. a., var. quercifolia), 

 Fig. 100. A very interesting form of the last species, of a 

 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 (Ptelea trifoliata).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 

 circular-winged fruit that somewhat resemble large clusters 

 of the fruit of the common hop-vine. 



Oaks. These trees are, many of them, emblems of 

 grandeur and strength, yet some of the species and varie- 

 ties possess graceful and pleasing outlines and beautiful 

 colors of foliage. In size many of them are not suited to 

 small places, and yet a single large oak with a cottage and 



