STREET TREES. 15 
Narrow streets should be planted with columnar trees (fig. 14) 
or sometimes with small trees. Broad streets may be planted with 
spreading trees (figs. 3... 
‘and 16); or, if pro= 4 
vided with a central: 
parking space, with 
moderate -sized trees 
in the center and on 
the sides, or with trees 
on the sides suited to 
the space and formal 
trees in the center. 
(Fig. 15.) 
As a rule, trees na- 
tive to the locality 
that have been suc- 
cessfully grown in 
other cities should be 
given the preference. 
When a choice must 
be made between un- 
tried native trees and 
those tested in a city 
or town under differ- 
P12536HP 
ent soil oe chmatic Fie. 14.—Narrow upright trees (Lombardy poplars) on a narrow 
conditions, it is better street. Washington, D. C.; midsummer. 
to give the native trees 
the first trial. There 
are Many native trees 
that are promising 
which have not been 
planted on a sufficient 
scale or under suffi- 
ciently varied condi- 
tions to demonstrate 
their real value for 
street planting over 
any considerable ‘area. 
Many of the trees men- 
tioned in this bulletin 
—..] May prove valuable 
PiesssHP = =far beyond the areas 
Fic. 15.—Formal trees in a central parking, but appropriate trees 5 
wanting on the sides of the street. Canary Island date palms in for which they are sug- 
Merced, Calif.; midsummer. | gested. The burr oak, 
the swamp white oak, the scarlet oak, the chestnut oak, the white 
oak, the sour gum, and others may be found on further trial to be as 
