76 Trees, Stars, and Birds 



scarce. In such places people use the wood for fuel 

 and for other purposes. Boards made of it warp badly, 

 especially when exposed to moisture, and are inferior 

 in both strength and durability to boards made from 

 most other woods. The tree is a very rapid grower, 

 sometimes increasing in diameter 10 inches in as many 

 years. The wood is soft and light colored and is much 

 used for paper pulp. 



Objections to the cottonwood as a shade tree. The 

 leaves of the cottonwood, being smooth, do not catch 

 soot and dust like those of the elm. On this account 

 and because of its rapid growth, this tree (especially 

 the variety known as the Carolina poplar) has been 

 planted along many city streets. Like many other 

 things that are cheap, the cottonwood usually proves 

 unsatisfactory. It is attacked by several kinds of 

 insects and is likely to be short lived. It is not orna- 

 mental, and its capsules and cottony seeds and in 

 summer its leaves and twigs litter the ground. Its 

 roots, sometimes more than 100 feet long, in their search 

 for water send their rootlets into drains and obstruct 

 the drainage ; they have been known even to break 

 through the cement linings of cisterns. Some cities 

 have passed ordinances forbidding the planting of this 

 tree. 



Aspens. The American aspen is a small species of 

 poplar with light-colored bark and soft, light wood. 

 It is found through the cool portions of North America 

 and grows in poor soil, often springing up extensively 

 where woods have been burned. Beavers cut it down 

 with their strong, sharp incisor teeth, using it to build 



