28 BULLETIN 816, U. S. DEPARTMENT 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 will 
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 treessucceed. 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 small,round headed, 
pooo2Hp =» With small dark-green 
Fic. 20.—A Norway maple, as seen in late winter, showing its poor : 
shape when trimmed to a high head. 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 
1 Acer negundo L. 2 Acer campestre L. 3 Acer platanoides L. 
