96 



Native Trees of Canada 



The rock elm grows on a wide range of soils, from dry and gravelly or heavy 

 clay soils to the rich, moist banks of streams. It is found solitary or mixed with 

 other hardwoods. 



In Canada it is confined to the southern parts of Quebec and Ontario and prob- 

 ably does not extend north beyond the Ottawa river or Georgian bay. 



The wood of this elm is the hardest, toughest, and strongest of the American 

 species. It is preferred to white elm for framework in pianos, heavy machinery, 

 shipbuilding, and vehicle stock. Otherwise the two species have similar uses. 



THE HACKBERRIES 



Fifty or more species of hackberry (Celtis) are found throughout the world in 

 both the north temperate and tropical regions. They are mostly shrubs and 

 small trees of no economic importance. They belong to the same group as the 

 elms and resemble them in many respects. The wood is like that of the elm 

 except that it is somewhat heavier, harder, and more brittle. In cross-section it 

 shows the zigzag lines of minute pores which is the characteristic marking of this 

 group. 



