Family Hippocastanaceae
Aesculus Hippocastanum

The Horse Chestnut is a native of the mountain regions of Greece, Bulgaria, Iran and Northern India, and is believed to have been introduced to Britain late in the sixteenth century. It is not a tree that will be found in the woodlands, or even by the wayside; yet it constantly greets the rambler in the public parks and gardens, where by contrast it exhibits itself as the grandest of all flowering trees. Though the stout, cylindrical bole is short, its erect trunk towers to a height of eighty or a hundred feet, supporting the massive pyramid.
The stout branches take an upward direction at first, then stretch outward and curve downwards, though in winter, when relieved of the weight of foliage, their extremities curl sharply upward, and the great buds, in spring, are almost erect.
These brown buds, with their numerous wraps and liberal coating of resin, afford considerable interest in early spring. They gradually swell and polish comes upon them through the daily melting of their varnish under the influence of the sunshine. Then the outer scales fall flat, the upper parts show green and loose; there is a perceptible lengthening of the shoot, which leaves a space between those outer wraps and the folded leaves. Next the leaflets separate and assume a horizontal position as they expand. The lengthening of the shoot brings the incipient flower-spike into view.
The leaves are almost circular, but broken up, finger-fashion, into, usually, seven-toothed leaflets of different sizes, but to prevent overcrowding their neighbours the portion nearest the leaf-stalk has taken a wedge-shape. The large size of these leaves – as much as eighteen inches across – leads the non-botanical to regard the leaflets as being full leaves. On emerging from the bud the leaves are seen to be covered with down, but as they expand this is thrown off.
The flowers consist of a bell-shaped calyx with five lobes, supporting four or five separate petals, pure white, but splashed and dotted with crimson and yellow towards the base of the upper ones, to indicate the way to the nectar glands. There are seven curved stamens, and in their midst a longer curved style proceeding from a roundish ovary with three cells. In each cell there are two seed-eggs, but as a rule only one egg in two of the cells develops into a “nut”. The ovary develops into a large fleshy blur, with short stout spines, which splits into three valves when the dark-red glossy seed are ripe. Though horses will not eat this bitter fruit, cattle, deer and sheep are fond of it.
The growth of the tree is very rapid, and consequently the timber is soft and of no value where durability is required. Still, its even grain and the ability to take a high polish makes it useful for indoor work, such as cabinet-making, etc.
The tree begins to produce fruit about its twentieth year, and continues to do so nearly every year. Its age is estimated as about two hundred years. The bark, at first smooth, breaks into irregular scales, and in old trees a twist may be developed.
The Red-flowered Horse Chestnut (Aesculus carnea) is a smaller and less vigorous tree. It is believed to be a garden hybrid between A. Hippocastanum and A. Pavia that made its appearance about 1820.