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.
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.
HORSECHESTNUT SHOOT
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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.
Enlarged longitudinal section of the bud of a horsechestnut, showing two folded, undeveloped leaves and an undeveloped spike of flowers.
Chapter III
THE MAPLES
1. Sugar Maple. 2. Silver Maple. 3. Red Maple. 4. Moosewood. 5. Mountain Maple. 6. Norway Maple. 7. Sycamore. 8 A and B. Ash-leaved Maple, showing the varying color of the stems.