STREET TREES. 23 
been the standard street tree of New England, giving to the roadsides 
and village streets the characteristic appearance which is so attractive 
to summer visitors. | 
- The American elm is tall and spreading, and where planted as near 
together as is customary on streets and country roads the effect of 
the mature ‘trees is that of an arch formed by the growing together 
of their spreading tops. It is of rapid growth and long lived. 
This elm drops its leaves very early in the fall, but it comes into 
leaf early in the spring. Because of its manner of branching it is 
especially liable to be split by heavy winds. This trouble may be 
lessened by selecting and planting specimens with a close, compact 
habit of growth or possibly also by great care in training young trees. 
Two limbs separating from one another by a very small angle, that 
is, when they start to grow in nearly the same direction, make a 
crotch that is lable to split. (Fig. 18.) Where two limbs separate 
at nearly a right angle or where three or more limbs of about equal 
size grow from a common point or very nearly so, the crotch is likely 
to be much stronger. Careful pruning and training to provide a 
proper system of branches may be especially helpful with this elm. 
Because of the attacks of the elm leaf-beetle* and the European 
elm bark louse,? many handsome trees have been severely damaged 
or killed before communities were properly equipped for fighting 
.them, for with careful spraying these insects may be kept in check. 
However, on account of the existence of these pests and because 
they are gradually spreading to new territory, tree planters should 
consider carefully whether it is advisable to plant the elm in their 
localities. Where there is no danger from these insects, this elm is 
one of the best of street trees. Consultation with the nearest State 
agricultural experiment station or with the Entomologist of the 
United States Department of Agriculture would be advisable in order 
to determine this point. | 
The best specimens are to be found in the northern part of region 
10, although the elm is being grown all over the United States and 
is proving a valuable street tree even in towns and villages of re- 
gions where the rainfall is as low as 15 inches. It is not recom- 
mended for planting in regions 3 and 5. 
The English elm ? is a tall, oval-headed, compact, handsome tree 
with leaves smaller than the Domeninem aliea and which stay on much 
later in the fall. In regions 1 and 2 it is at its best, in the former 
thrives in regions 3 and 10 and in the eastern part of region 11. 
The Huntingdon elm # is a comparatively round-headed European 
variety. 
1 Galerucella luteola Mill. 3 Ulmus campestris L. 
2Gossyparia spuria Mod. (Data regarding both 4 Ulmus hollandica vegeta (Lindl.) Rehd. 
insects furnished by the Bureau of Entomology.) 
\ 
_ equaling the American elm and in the latter excelling it. It also 
