How are the scales of the Beech bud arranged?
How many leaves are there in the bud?
How does the arrangement of the scales and leaves in the bud differ from
that of the Horsechestnut?
How are the leaves folded in the bud?
What is the arrangement of the leaves on the stem?
How does this differ from Horsechestnut and Lilac?
How old is your branch?
How old is each twig?
What years were the best for growth?
How does the growth of the branches differ from that of Horsechestnut?
From Lilac?
Explain these differences with reference to the growth and arrangement of
the buds?
In what direction do the twigs grow?
How does this affect the appearance of the tree?
Compare the amount of spray of the Beech and Horsechestnut and explain the
reason of the difference.
These questions are only intended for review, they are never to be used
for the first study of the specimen.
AMERICAN ELM (_Ulmus Americana_).
The buds are covered with brown scales, which are hairy on the edges. The
flower-buds are larger than the leaf-buds and are in the axils of the
lower leaves of the preceding year. Each leaf in the bud is enclosed by
a pair of scales. They are so small that the pupils, unused to delicate
work, will hardly discover them. Under a glass they can be seen to be
ovate, folded on the midrib with the inner face within (_conduplicate_),
and with an ovate scale joined to the base of the leaf on either side. The
scales thus show themselves to be modified stipules. The venation of the
leaves is very plain. The scales are much larger than the leaves. The
flower-buds contain a cluster of flowers, on slender green pedicels. The
calyx is bell-shaped, unequal, and lobed. The stamens and pistil can
be seen. The flower-clusters do not seem to leave any mark which is
distinguishable from the leaf-scar.
[Illustration: FIG. 16.--American Elm. 1. Branch in winter state: _a_,
leaf-scars; _b_, bud-scars; _d_, leaf-buds; _e_, flower-buds. 2. Branch,
with staminate flower-buds expanding. 3. Same, more advanced. 4. Branch,
with pistillate flowers, the leaf-bud also expanding.]
The leaf-scars are small and extend about half around the stem. The
arrangement is alternate on the one-half plan. There are three dots on the
scar.
The rings are quite plain. The tree can be used to make tables of growth,
like those of the Beech.
The buds will probably be too small for examination by the pupils, at
present, but their position and development can be studied, and are very
instructive. As the leaf-buds are all on the ends of the branchlets, the
twigs and branches will be just below the bud-rings, and then there will
be a space where no twigs nor branches will be found, till the next set
of rings is reached. This gives the branches more room to develop
symmetrically. The terminal buds do not develop in the Elm, in old trees,
the bud axillary to the last leaf of the season taking its place, and most
of the other axillary buds growing also. This makes the tree break out
into very fine spray. A tree like the Elm, where the trunk becomes lost in
the branches, is called _deliquescent_; when the trunk is continued to the
top of the tree, as in the Spruce, it is _excurrent_.
The small, feathery twigs and branches that are often seen on the trunks
and great limbs of the elm grow from buds which are produced anywhere on
the surface of the wood. Such buds are called _adventitious_ buds. They
often spring from a tree when it is wounded.
"The American elm is, in most parts of the state, the most magnificent
tree to be seen. From a root, which, in old trees, spreads much above
the surface of the ground, the trunk rises to a considerable height in a
single stem. Here it usually divides into two or three principal branches,
which go off by a gradual and easy curve. Theses stretch upwards and
outwards with an airy sweep, become horizontal, the extreme half of the
limb, pendent, forming a light and regular arch. This graceful curvature,
and absence of all abruptness, in the primary limbs and forks, and all the
subsequent divisions, are entirely characteristic of the tree, and enable
an observer to distinguish it in the winter and even by night, when
standing in relief against the sky, as far as it can be distinctly
seen."[1]
[Footnote 1: A Report on the Trees and Shrubs growing naturally in the
Forests of Massachusetts. By Geo. B. Emerson, Boston, Little, Brown and
Co., 1875.
This book will be found very useful, containing careful descriptions of
many trees and shrubs, and interesting facts about them.]