66 PRACTICAL ARBORICULTURE 



THE MAPLES. 



Almost the only maple used in your street planting and home grounds 

 is the silver maple {Acer dasycarpum). This, too, is a pioneer tree, probably 

 the most rapid growing of the maple family. Properly pruned when young, 

 and kept trimmed in at all times, it may be formed into a round head, but it 

 requires constant pruning. The branches are brittle, very long, easily broken 

 in wind, or with an accumulation of snow. It is a good tree to plant alter- 

 nately with other somewhat slower growing trees, but is very unsatisfactory 

 where exclusively used. 



Scarlet maple (Acer rubrum) is better; has a round head, is a quick 

 grower, and is very handsome, as it colors its foliage in autumn. 



Sugar or rock maple (Acer saccharinum) is one of the very best street 

 trees in America and succeeds in Colorado. It is very free from insects. Its 

 growth is slightly slower than the two first mentioned varieties, but its foliage 

 is superb. It requires little or no pruning, and less water than the two swamp 

 maples. Its home is on rolling and mountainous lands ; has a tap root which goes 

 deep after moisture and food. 



Norway maple (Acer platanoides) is an excellent, hardy tree, not a slow 

 grower if well cared for. 



GINKGO 



This tree was imported from Japan some forty or fifty years ago and is 

 among the finest avenue trees of Washington City. 



It is growing finely in Colorado and every other state in the Union. The 

 leaves are unique, bright green foliage, fan-shaped, narrow at the stem end. 

 Its fruit, a delicious nut, with paper shell, enclosed in a disagreeable fruit 

 pulp, the size of a plum. 



Under good culture its growth is by no means slow. It is suited to the 

 lawn better than as a street tree. 



RUSSIAN OLIVE 



is a fine arid region tree ; very satisfactory and numerous at Denver and some 

 at Colorado Springs. Its silvery foliage gives variety to surrounding trees. 



TULIP TREE 



(Liriodendron tuUpifcra*) is the grand forest tree of Indiana and elsewhere, 

 called yellow poplar. It is a clean, rapid growing, handsome street tree, or for 

 the lawn. A few are growing in Denver, and I have no doubt it will be 

 perfectly satisfactory here. Rather difficult to transplant, like the Magnolia 

 family; and should be removed only in spring. Small trees are more success- 

 ful than larger ones. 



LINDEN OR BASSWOOD 



grows well in Colorado and makes a good dense shade, having a round head 

 and being a handsome tree. 



When trees of this smooth-like bark are trimmed up with long trunks, 



