MOST AVAILABLE TBEES FOR PLANTING. 63 



tractive. If these thorns are objectionable they can be re- 

 moved or a thornless horticultural form may be used. The 

 tree is somewhat late in unfolding its leaves, yet that is 

 hardly a disadvantage. The long, coarse, pods that litter the 

 I avcments in the fall, or hang on the branches in winter, are 

 more objectionable. 



MAPLE. 



.N'> trees have been more widely used for street planting 

 than the maples, yet in too many cases the wrong species has 

 been, employed, or the trees used in situations to which they 

 an- imt suited. White, silver or soft maple (Acer sacchari- 

 num, L.) is planted everywhere, yet it is a poor tree, and 

 for the reasons given on page 13 is not recommended. Nor- 

 way maple (A. platanoides, L.) is altogether the best tree 

 that we have for streets of moderate width. It is symmetri- 

 cal in form, adaptable to almost any soil, hardy, and a fairly 

 rapid grower. In autumn its foliage takes on the most bril- 

 liant coloring. The tree is little subject to serious diseases. 

 Though several insects frequently attack it they usually do 

 little harm. The drying of the leaves often noticed in early 

 snmmer is usually due to deficient moisture, or to sunburn. 

 It is to be prevented whenever possible, though it rarely does 

 harm. (See page 116.) Red maple (A. rubrum, L.) is of 

 somewhat more slender habit than Norway maple and thrives 

 best in moist soil. It also is a good tree for streets of mod- 

 erate width, though it sometimes suffers from sunburn. The 

 younger branches are reddish and in autumn the coloring of 

 rhe foliage is brilliant. Sugar maple (A. saccharum, 

 Marsh.) is a larger tree than Norway maple, though in many 

 respects so much like it that the two are often hard to dis- 

 tinguish. It thrives in cool situations, but invariably suffers 

 when planted along paved streets. Except on wide streets 

 with parking the Norway maple is always to be preferred. 

 Ash-leaved maple, or box elder (A. negundo, L.) is a small 

 tret- whose only merit is that it accommodates itself to ad- 

 verse conditions. It is short lived like silver maple, and is 

 not recommended for the same reasons. 



