re flower-buds.
The leaf-scars are small, with three dots on each scar. The rings are very
plain. The flower-cluster leaves a round scar in the leaf-axil, as in
Cherry.
The leaves are opposite and the tree branches freely. The twigs seem to
be found just below the bud-rings, as the upper leaf-buds usually develop
best and the lower buds are single, containing flowers only.
NORWAY SPRUCE (_Picea excelsa_).
The buds are terminal, and axillary, from the axils of the leaves of the
preceding year, usually from those at the ends of the branchlets. They
are covered with brown scales and contain many leaves.
[Illustration: FIG. 18.--Branch of Cherry in winter state: _a_, leaf-scar;
_b_, bud-scar; _c_, flower-scar.]
[Illustration: FIG. 19.--Branch of Red Maple in winter state (reduced). 2.
Flower-buds]
The leaves are needle-shaped and short.[1] They are arranged densely on
the branches, alternately on the 8/21 plan (see section on phyllotaxy).
When they drop off they leave a hard, blunt projection which makes the
stem very rough. As the terminal bud always develops unless injured, the
tree is excurrent, forming a straight trunk, throwing out branches on
every side. The axillary buds develop near the ends of the branchlets,
forming apparent whorls of branches around the trunk. In the smaller
branches, as the tree grows older, the tendency is for only two buds to
develop nearly opposite each other, forming a symmetrical branch.
[Footnote 1: The pupils should observe how much more crowded the leaves
are than in the other trees they have studied. The leaves being smaller,
it is necessary to have more of them. Large-leaved trees have longer
internodes than those with small leaves.]
The bud-scales are persistent on the branches and the growth from year to
year can be traced a long way back.
The cones hang on the ends of the upper branches. They are much larger
than in our native species of Black and White Spruce.
The Evergreens are a very interesting study and an excellent exercise in
morphology for the older scholars.
2. _Vernation_. This term signifies the disposition of leaves in the bud,
either in respect to the way in which each leaf is folded, or to the
manner in which the leaves are arranged with reference to each other.
The pupils have described the folding of the leaves in some of their
specimens.
In the Beech, the leaf is _plicate_, or plaited on the veins. In the Elm,
Magnolia, and Tulip-tre
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