[Illustration: FIG. 71.--Twig of the Black Walnut. Note the large
chambers in the pith.]

[Illustration: FIG. 72.--Twig of the Butternut. Note the small chambers
in the pith.]

Other characters: The _fruit_ is a large round nut about two inches in
diameter, covered with a smooth husk which at first is dull green
in color and later turns brown. The husk does not separate into
sections. The kernel is edible and produces an oil of commercial
value.

The _leaves_ are compound and alternate with 15 to 23 leaflets to
each.

Comparisons: The _butternut_ (_Juglans cinerea_) is another tree that
has the pith divided into little chambers, but the little chambers
here are shorter than in the black walnut, as may be seen from a
comparison of Figs. 71 and 72. The bark of the butternut is light
gray while that of the black walnut is dark. The buds in the
butternut are longer than those of the black walnut and are light
brown instead of gray in color. The form of the tree is low and
spreading as compared with the black walnut. The fruit in the
butternut is elongated while that of the black walnut is round. The
leaves of the butternut have fewer leaflets and these are lighter in
color.



GROUP X. TULIP TREE, SWEET GUM, LINDEN, MAGNOLIA, LOCUST, CATALPA,