nguishing characters: Its *tall, slender, spire-like form* and
rigidly *erect branches*, which commence low on the trunk, make this
tree very distinct at all seasons of the year. See Fig. 39.

Leaf: Triangular in shape, similar to that of the Carolina poplar but
smaller, see Fig. 40.

Range: Asia, Europe, and North America.

Soil and location: The poplar is easily grown in poor soil, in any
location, and is very hardy.

Value for planting: The tree has a distinctive form which makes it
valuable for special landscape effects. It is also used for shelter
belts and screening. Like all poplars it is short lived and will
stand pruning well.

Commercial value: None.

[Illustration: FIG. 41.--Carolina Poplar.]

Comparisons: The _Carolina poplar_, or Cottonwood (_Populus deltoides_)
can be told from the Lombardy poplar by its wider crown and its more
open branching, Fig. 41. It may be recognized by its big terminal
twigs, which are light yellow in color and coarser than those of the
Lombardy poplar, Fig. 42. Its bark is smooth, light and
yellowish-green in young trees, and dark gray and fissured in older
specimens. Its large, conical, glossy, chestnut-brown bud is also
characteristic, Fig. 42. Its flowers, in the form of large catkins,
a peculiarity of all poplars, appear in the early spring. The
Carolina poplar is commonly planted in cities because it grows
rapidly and is able to withstand the smoke and drouth conditions of
the city. Where other trees, however, can be substituted with
success, the poplar should be avoided. Its very fast growth is
really a point against the tree, because it grows so fast that it
becomes too tall for surrounding property, and its wood being
extremely soft and brittle, the tree frequently breaks in
windstorms. In many cases it is entirely uprooted, because it is not
a deep-rooted tree. Its larger roots, which spread near the
surface, upset the sidewalk or prevent the growth of other
vegetation on the lawn, while its finer rootlets, in their eager
search for moisture, penetrate and clog the joints of neighboring
water and sewer pipes. The tree is commonly attacked by the
_oyster-shell scale_, an insect which sucks the sap from its bark
and which readily spreads to other more valuable trees like the elm.
The female form of this tree is even more objectionable than the