THE HORSECHESTNUT
Family Hippocastanaceæ
This a small family consisting of one well-known cultivated
species,—the horsechestnut,—and four belonging to the Western and
Southern States,—the various large and small buckeyes.
The horsechestnut is so well known and its winter characteristics so
clearly marked that I have chosen it first for description, although no
species of the family is found growing wild in the Northeastern States.
[Sidenote: Horsechestnut
_Æsculus hippocastanum_]
_A large tree with a pyramidal head. The bark of old trees splits off
in small square pieces, and in young trees it is smooth. Very coarse
twigs and large brown buds covered with a gummy substance. Opposite
leaf-scars._
The horsechestnut has little grace or beauty of outline in winter. Its
branches are stiff, the twigs are coarse, ending bluntly with large
terminal buds, and the general shape too compact to be pleasing. The
buds and recent shoots are particularly interesting however, as every
scar is sharply defined and the buds are so large we can see the
inner structure perfectly. In the accompanying illustration we see a
two-year-old shoot with a large terminal bud and two lateral buds below
the ring of scars left by the scales of the terminal bud of the year
before. The bundle-scars are plainly seen on the leaf-scars, and above
one of the leaf-scars there is a lateral bud ready to develop into a
lateral branch when it opens in the spring. The circle of scars at the
base of each lateral shoot was left by the scales of the lateral bud
of the year before. There are one or two small undeveloped buds at the
top of the leaf-scars which would carry on the growth of the branch
if anything happened to injure the vigorous buds at the tips of the
stems. The dots on the bark are the lenticels. By opening the bud with
a knife we find beneath the sticky gummy substance and the numerous
layers of scales a complete branch in miniature. The little leaves
are carefully packed in downy wool to keep out the dampness and cold,
and in their turn they protect the delicate pink spike of flowers. A
German naturalist once counted sixty-eight flowers on one of these
undeveloped spikes in the bud, and with a microscope he discovered the
pollen of the stamens.
[Illustration: HORSECHESTNUT SHOOT
Page 16
]
The horsechestnut came originally from Southeastern Europe and was
introduced into gardens about the middle of the sixteenth century.
Its wood has no commercial value. The generic name, _Æsculus_, comes
from _esca_, food, the ancient name of an oak with edible acorns; it
was probably given to this tree on account of its large chestnut-like
fruit. _Hippocastanum_, from _hippos_, a horse, _castanea_, a chestnut,
alludes to the fruit which is made into horse medicine in Turkey.
The Ohio buckeye (_Æsculus glabra_) is a shrub or low tree found west
of the Alleghanies. Its terminal bud is frequently lacking, and the two
upper lateral buds grow large and take its place. Its buds and stems
resemble those of the horsechestnut, but the two species would never be
confused.
[Illustration: Enlarged longitudinal section of the bud of a
horsechestnut, showing two folded, undeveloped leaves and an
undeveloped spike of flowers.]