blue beech. The color of the bark in the ironwood is brownish, while
that of the blue beech is bluish-gray. The buds of the ironwood are
greenish with brown tips, while the bud of the blue beech shows no
green whatever.


HACKBERRY (_Celtis occidentalis_)

Distinguishing characters: The tree may be told readily from other trees
by the *corky tubercles* on the bark of the lower portion of the
trunk. See Fig. 56.

Leaf: Has three predominating veins and is a bit more developed on one
side than on the other.

Form and size: A small or medium-sized tree with a single stem and broad
conical crown.

Range: United States and Canada.

Soil and location: Grows naturally in fertile soils, but will adapt
itself to almost sterile soils as well.

Enemies: The hackberry is usually free from disease, though often its
leaves are covered with insect galls.

Value for planting: It is extensively planted as a shade tree in the
Middle West, and is frequently seen as an ornamental tree in the
East.