; others show branches which grew from the axillary buds, many of
them fruiting branches (Figs. 37, 42, 43, 50, and 54), one (Fig. 51) a
thorny branch.

The cone-bearing plants (Figs. 59-67) have only simple leaves. Each
piece, no matter how small and scale-like, may have a branch growing
from its axil, and so may form a whole leaf. A study of these figures,
together with the observation of trees, will soon teach the student
what constitutes a leaf.

ARRANGEMENT.--There are several different ways in which leaves are
arranged on trees; the most common plan is the _alternate_;
[Illustration] in this only one leaf occurs at a joint or node on the
stem. The next in frequency is the _opposite_, [Illustration] where two
leaves opposite each other are found at the node. A very rare
arrangement among trees, though common in other plants, is the
_whorled_, [Illustration] where more than two leaves, regularly arranged
around the stem, are found at the node. When a number of leaves are
bundled together,--a plan not rare among evergreens,--they are said to
be _fasciculated_ or in _fascicles_. [Illustration] The term _scattered_
is used where alternate leaves are crowded on the stem. This plan is
also common among evergreens.

CAUTION.--In some plants the leaves on the side shoots or spurs of a
twig are so close together, the internodes being so short, that at first
sight they seem opposite. In such cases, the leaf-scars of the preceding
years, or the arrangement of the branches, is a better test of the true
arrangement of the leaves. The twig of Birch shown in Fig. 5 has
alternate leaves.

[Illustration: Fig. 5.]

[Illustration: Fig. 6.]

There is one variety of alternation, called _two-ranked_, which is quite
characteristic of certain trees; that is, the leaves are so flattened
out as to be in one plane on the opposite sides of the twig (Fig. 6).
The Elm-trees form good examples of two-ranked alternate leaves, while
the Apple leaves are alternate without being two-ranked. Most leaves
spread from the stem, but some are _appressed_, as in the Arbor-vitae
(Fig. 7). In this species the _branches_ are _two-ranked_.

PARTS OF LEAVES.--A _complete leaf_ [Illustration] consists of three
parts: the _blade_, the thin expanded portion; the _petiole_, the
leafstalk; and the _stipules_, a pair of small blades at the base of the
petiole. The petiole is often very short and sometimes wanting. The
stipules are often absent, and, ev