; STREET TREES. 33 
streets, and especially on boulevards, where the good of the future 
as well as the present is considered. 
The burr oak,! or mossy-cup oak, is native in the northeastern 
United States and west of the Mississippi River on the hills lying 
between the river bottoms and the prairies west to the western parts 
of the Dakotas and Nebraska and central Kansas and Texas. It is a 
large, handsome tree that should prove satisfactory under suburban 
conditions in regions 7, 8, 9, 10, and 11 and on fertile well-watered soils. 
The pin oak,? sometimes called the swamp oak, is a tall tree, conical 
when young, oval at maturity, with a drooping habit of the lower 
branches. The leaves are quite finely divided and are of a bright 
PI4413HP 
Fic. 24.—A street shaded with red oaks, Washington, D. C.; midsummer. 
glossy green. The tree comes into leaf late in the spring and holds its 
foliage late in the fall. One objection to the pin oak for street 
planting is that on many specimens the dead leaves hang on through 
the winter. It is adapted to narrower streets than the red oak, as its 
habit of growth is not so spreading. On account of the tendency of 
the limbs to droop, particularly as they get older, it is desirable 
that a good strong leader should be developed, so that the lower 
limbs may be removed from time to time as conditions require. 
The pin oak thrives on wet and on heavy clay soils, as well as on a 
wide range of other soils. Figure 4 shows pin oaks, Norway maples, 
and ginkgos 18 years old on adjacent streets, and illustrates the 
rapid growth of this oak. At the time of planting these trees the pin 
oaks were thought to have the poorest location. This tree is adapted 
to regions 1, 2, 3, 4, 9, 10, and 11. 
1 Quercus macrocarpa Michx. 2Quercus palustris L. 
