A Street Tree System for New York City 49 



(Tilia platyphyllos) the large-leaved European Linden 

 which is badly affected by the red spider and is a generally 

 inferior tree in many ways. There are two other lindens, 

 probably equally as good for street use as Tilia vulgaris. 

 These are Tilia cordata, the small-leaved European Linden 

 and Tilia tomentosa, the Silver Linden. These have not 

 been used so long as street trees in America and so less is 

 known about them. 



(4) Acer platanoides (The Norway Maple). 



This is the best Maple which can be grown successfully 

 on city streets. There are several horticultural varieties of 

 this tree on the market which may prove superior to the type 

 when better known. The varieties differ from the type prin- 

 cipally in form. Two of the best are var globosum which is 

 very round and formal and var columnare which is tall and 

 columnar. The type tree forms a round-headed, attrac- 

 tive appearing tree so well known that a detailed descrip- 

 tion is not necessary. While subject to a number of in- 

 sect pests the tree can be kept in good health with reasonable 

 care. The Norway Maple stands street conditions very well, 

 but it is less hardy than the Plane and Gingko, and should 

 only he used where soil and moisture conditions are fairly 

 good. It is not as well adapted for use beneath gratings as 

 the Linden, Plane or Gingko. The Norway Maple is to be 

 recommended for use on residence streets where fair-sized 

 tree pits or parking areas are available. The photo on page 

 16 shows the beauty of a street planted to Norway Maples 

 when the trees are well grown. 



5. Quekctjs palusteis (The Pin Oak). 



While less hardy than the Plane <",::d Gingko, the Pin Oak 

 will make a splendid growth in a very restricted area if soil 

 conditions are reasonably good. Being a slow grower it is 

 very easy to keep it of small size by pruning and in this way 

 the top may be kept in balance with the root growth where 

 the space available for the roots is limited. An example of 

 this is seen in the present successful planting on North Broad- 



