28 



BULLETIN 816, U. S. DEPAETMENT OF AGRICULTURE. 



street planting as usually has been supposed, few of the species 

 being suitable for this purpose and these only in a limited way. 

 The ash-leaved maple, or box elder,^ is native to all of the country 

 east of the Rocky Mountains except the regions near the South 

 Atlantic and Gulf coasts. It is a small, quick-growing tree that wiU 

 thrive almost anywhere, but it reaches maturity early. Because of its 

 early decay and of its being subject to destruction by wind, it should 

 not be used for street planting where other trees succeed. It would be 



a good tree for inter- 

 planting were it safe 

 to risk taking out 

 some of the trees at 

 the right time. The 

 objection to using 

 these trees is that 

 they would be so 

 likely to look larger 

 and better than the 

 permanent trees at 

 the time they should 

 be removed that pub- 

 lic opinion would 

 probably resent their 

 removal. There may 

 be conditions requir- 

 ing the use of this tree 

 in regions 6, 7, and 8, 

 but it should be grown 

 only when the other 

 trees suggested for 

 these regions will not 

 succeed. 



The English maple ^ 

 is Ismail, round headed, 

 with small dark-green 

 leaves, useful in re- 

 gions 1, 2, 3, and 4. 

 The Norway maple ^ is round headed and eventually reaches 

 large size, but, as compared with most of the other maples, it is 

 slow growing (fig. 4, C). The persistence of its tendency to form 

 a low head makes it difficult to give it a high head of desirable shape 

 (fig. 20). It is also very thickly branched, and its foliage, being 

 heavy and dark green, permits but little light to pass through. On 

 this account it is rather undesirable for street planting. By severe 

 pruning of the interior of the head this defect may be somewhat 



P20042HP 



Fig. 20.— a Norway maple, as seen in late winter, showing its poor 

 shape when trimmed to a high head. 



1 Acer 



2 Acer campestre L. 



^ Acer platanoides L. 



