Horse Chestnut , (oesculus, Linn.), a tree of the natural order sapindaceoe, comprising about a dozen species, of which the most common and best known is AE. hippocastanum (Linn.), a handsome tree, with broad, digitate leaves, and large and showy spikes of white flowers, spotted with crimson and yellow, solely cultivated for ornamenting parks and streets, its wood being soft and of little value. The buds are remarkably large, and covered with a gummy varnish; the shoots push from them with great rapidity in spring, and the whole growth of the tree for the year is made in very short time. This species has long been in cultivation, but its native habitat has never been ascertained. The tree has been sometimes known to grow to the height of 80 ft., though ordinarily it does not attain to more than 40.
Common Horse Chestnut (AEsculus hippocastanum).
Its bark is astringent, and abounds in tannin; its fruit contains much starch, and has been used in fattening cattle, and given to horses afflicted with colds and coughs; from this circumstance it is said to have received its common name. It is unfit for the food of man. The nuts if not allowed to dry germinate freely, and penetrate 'the soil at once, by means of a strong tap root; the extremity of the root is sometimes broken off before they are set out, or sown after germination, thereby insuring the growth of more lateral roots. The fruit of the horse chestnut consists of its polished seed covered with a thick prickly husk that divides into three segments before it falls. There is a very handsome variety with deep rose-colored flowers, by some considered a species, one with double flowers, besides a form with variegated flowers, one with the leaflets deeply cut, etc. - The Ohio buckeye (AS. glabra, Willd.) is a smaller tree than the preceding, but sometimes reaching the height of 50 ft., with pale yellow inelegant flowers; it grows on river banks in western Pennsylvania, Kentucky, Ohio, and Michigan; its bark exhales an unpleasant odor, and its fruit is not half the size of the common horse chestnut; the timber is worthless.
A number of the species have the husk of the fruit without prickles; these smooth-fruited ones were formerly placed in a separate genus, pavia, but botanists now include them under oesculus. The red buckeye (AE. Pavia, Linn.) is an ornamental species, cultivated for the beauty of its flowers, which both in calyx and corolla are of a bright red; it is a small tree or large shrub, growing spontaneously from Virginia to Arkansas. The, sweet buckeye (AE.flava, Aiton), a large tree GO or 70 ft. high, with pale yellow blossoms, occurs in rich woods from Virginia to Indiana and southward, where it is only a shrub 4 to 6 ft. in height. Its timber is sometimes used in building log cabins, and bowls are sometimes turned from the wood. The variety purpu-rescens (AE. discolor, Pursh) is a southern form, with the leaves downy beneath and the flowers tinged with flesh color or dull purple. The dwarf horse chestnut or dwarf buckeye (AE. parviflora; Pavia macrostachya of the catalogues) is always a shrub, and one of the finest ornaments for the lawn; it forms a dense mass much broader than high, and in July bears numerous long slender spikes of white flowers, to which the long stamens give a fine feathery appearance; it multiplies abundantly by suckers.
The California buckeye or horse chestnut (AE. Californica) is a low spreading tree, found along streams; the rose-tinted flowers arc smaller than in the next preceding, and in a long more compact raceme; it is very ornamental.* - The Spanish buckeye is a name given in Texas to Ungnadia speciosa, a shrub 5 to 10 ft. high, found in western Texas. The genus differs from oeculus in having alternate leaves and in the structure of the flower; the nut. the size of a boy's marble, is nearly black and shining; the kernel sweet and pleasant to the taste, but with decided emetic properties. It is a pleasing ornamental shrub, hardy in Georgia, but not tested much further north.
Fruit of Common Horse Chestnut.
Red Buckeye (AEsculus Pavia).
Dwarf Buckeye (AEseulus parviflora).
The genus was named in honor of Baron Ungnad, who as Austrian ambassador to Constantinople first sent the seeds of the common horse chestnut to Vienna in 1815, and thus introduced that tree into western Europe.