Hydrangea, common name for certain deciduous and evergreen shrubs and woody vines. Hydrangeas are native to Asia and the Americas. The flowers are borne in clusters, the outermost flowers of which consist of a colored, membranous envelope, but the inner flowers of which have an eight- to ten-ribbed, tubular envelope, four or five ovate petals, eight to ten slender stamens, and a two-celled pistil. The fruit is a many-seeded capsule. The wild hydrangea of the eastern United States is an erect shrub that grows up to 3 m (up to 10 ft) high and bears white flowers in round clusters. The showier hydrangeas are cultivated Asian species, such as a typical cultivar of the hortensia, which grows up to 3.6 m (up to 12 ft) high; has broad, thick, shining leaves; and produces white, blue, or pink, flowers in round or flat clusters. The mock orange, a separate genus of the same family, also produces showy white flowers.Scientific classification: The genus Hydrangea belongs to the family Saxifragaceae. The wild hydrangea is classified as Hydrangea arborescens and the typical cultivar of the hortensia as Hydrangea macrophylla cultivar hortensia.
