Hydrangea (Gr. water, and a vase), a genus of shrubby plants, to which the name was applied for no obvious reason, belonging to the natural order saxifragacem, and natives of Asia and of North America. The species best known (II. Hortensia), the common hydrangea, was introduced into England from China in the year 1790 by Sir Joseph
Garden Hydrangea (H. Hortensia).
Banks. Commerson, wishing to honor his friend Mme. Hortense Lapeaute, called the plant Lapeautia;. but thinking the compliment not sufficiently pointed, he changed the name to Hortensia, by which it is still known in France; when it was found to belong to the old genus hydrangea, Commerson's generic name was retained for the species; it is often incorrectly written hortensis. It is a smooth, dwarf, vigorous shrub, with opposite, coarsely toothed, oval leaves, and bears immense globu- lar clusters of sterile flowers, which are white, pink, or blue, according to the nature of the soil. Cuttings of the wood or of the growing stems will root without difficulty. The hydrangea delights in an unlimited supply of water, fading at once on its being withheld. There is a variety with variegated foliage, nearly all silvery white, which is fine in the greenhouse, but does not endure our hot sun. Specimens are mentioned in England of 30 ft. circumference, and producing on a single clump more than 1,000 heads or corymbs of flowers. In the United States, even so far north as Boston, it will survive the winter if slightly protected by the stems being covered.
The wild hydrangea (H. arborescens, Linn.) is a shrub 4 to 6 ft. high; its flowers, which are borne on flat cymes, are white or yellowish, and usually all fertile, but sometimes with a row of sterile ones around the margin; the species ranges from Pennsylvania southward. The oak-leaved hydrangea (H. quercifolia) was first discovered by Bartram in Georgia; it was carried to England in 1803, and is the finest North American species; it has deeply lobed, oak-like leaves, and fine large corymbs of nearly white flowers, which change afterward to purple. In the gardens at the north is often seen the snowy-leaved hydrangea (H. nivea, Mx.), a shrub from 0 to 8 ft. high, with large leaves of a silvery whiteness beneath, and flowers in terminal cymes, having a few showy, white, sterile florets enclosing many small, green, fertile ones; it grows in the upper part of Georgia and the Caroli-nas. Within a few years several fine hydrangeas have been introduced from Japan, some of which, though they have received specific names, are varieties of H. Hortemia, while others are distinct; preeminent among these is H. paniculata grandiflora (sometimes called H. deutzifolia), which is one of the finest hardy shrubs in cultivation; it produces an oblong panicle, often a foot long, of sterile 'flowers, which are at first white, then gradually turn pink, and by the time frost comes they are brownish red.
Oak-leaved Hydrangea (H. quercifolia).