n.
Any of approximately 23 species of erect or climbing woody shrubs that make up the genus Hydrangea (family Hydrangeaceae).
It is native to the Western Hemisphere and eastern Asia. Several species are grown in greenhouses and gardens for their showy, usually ball-like flower clusters. Cultivated varieties of the French hydrangea, or hortensia H. macrophylla , bear large globular flower clusters in various colours; they are the florist's hydrangeas.