.=)

=U.= Leaves thin; bark of trunk peeling off in thin
horizontal strips 83. _Betula._

=U.= Leaves thin; leaf-buds long, slender, sharp-pointed;
bark smooth, not peeling; cultivated 90. _Fagus._

=U.= Leaves thickish; bark roughish; fruit an oval woody
cone, remaining on through the year 84. _Alnus._

=U.= Leaves thick; fruit an acorn 88. _Quercus._

=V.= Leaves evergreen, small, 2-3 in. long, thick, with
revolute margins; fruit an acorn 88. _Quercus._

=V.= Leaves evergreen, oval to lance-oval, usually large;
small trees, almost shrubs. (=d.=) page 56.

=V.= Leaves deciduous (some are evergreen in the Southern
States). (=W.=)

=W.= Plant more or less spiny. (=c.=)

=W.= Plant not at all spiny. (=X.=)

=X.= Leaf-blade thin, long, pointed, with curved parallel
veins or ribs 45. _Cornus._

=X.= Leaf-blade thin, circular or broadly oval in outline,
with blunt, almost rounded apex; veins not regularly
parallel 27. _Rhus._

=X.= Leaf quite elongated, 5 or more times as long as wide.
(=b.=)

=X.= Leaves with none of the above peculiarities. (=Y.=)

=Y.= Deciduous bud-scales (stipules), leaving a scar or
mark completely around the stem at the base of the
leaves. 1. _Magnolia._

=Y.= Leaves covered on one or both sides with silvery
scales 71. _Elaeagnus._

=Y.= No such ring around the stem, or silvery scales on
the leaves. (=Z.=)

=Z.= Leaves distinctly straight-veined, thin 90. _Fagus._

=Z.= Leaves thick, obtuse; fruit an acorn 88. _Quercus._

=Z.= Leaves 6 in. or more long; crushed leaves with a rank,
fetid odor 5. _Asimina._

=Z.= Leaves 3-5 in. long; twigs and leaves very spicy; shrub
rather than tree 70. _Lindera._

=Z.= Leaves about 2 in. long, oval, on twigs which have
ridges extending down from the sides of the leafstalk;
small tree, almost a shrub, with beautiful flowers
43. _Lagerstro