162 THE BOOK OF FORESTRY 



habit of sending its roots into drains and sewers in 

 search of water with the result that the sewage is 

 forced back into the house. In many cities the plant- 

 ing of poplars in the streets has been forbidden by law. 



Box Elder. The box elder is likely to be ill-shapen 

 and to suffer greatly from insect attacks. 



Catalpa. The catalpa is objectionable on account of 

 the litter it drops. 



Horse Chestnut. This tree also litters the ground 

 beneath and is quite likely to become a menace to 

 passers by on account of its tendency to split and 

 break. Practically all fast-growing trees are short- 

 lived and are apt to be brittle. Such trees may be used 

 for special purposes but should be followed by more 

 desirable individuals. 



American Elm and Hard Maple. Certain trees like 

 the American elm and hard maple are beautiful shade 

 trees but on account of insect enemies should not be 

 planted in certain regions. Throughout southern New 

 England the elm can hardly be kept alive without one or 

 two sprayings each spring with lead arsenate to kill the 

 elm leaf beetle, while the frequent attacks of the maple 

 borer make many beautiful round-headed sugar maples 

 unsightly in a very short time. The use of such trees 

 must depend upon local conditions. 



Norway Maple and Plane Tree. One of the most 

 popular trees for street planting today is the Norway 

 maple. It is a compact tree with round dense crown 

 having foliage that is a dark rich green. It is com- 

 paratively free from attack. Another desirable tree is 

 the Oriental sycamore or plane tree. Not only is it a 

 rapid grower but it is comparatively long-lived which 

 makes it one of the best for street planting. Such 

 trees as the European linden and certain of the oaks 



