A genus of shrubs (N.O. Saxifragaceæ), natives of the temperate regions of Asia and America, with white, blue, or pink flowers in large globular…

A variety of the common hydrangea, Hydrangea macrophylla, variant hortensia.

Chiefly English regional. The flowers of the mock orange, Philadelphus coronarius, which resemble those of an orange tree in scent; (also orange-…

any of a group of hydrangeas having flattened corymbs with small fertile flowers in the centre and larger sterile ones around the edge; frequently…

Horticulture. A plant having compact rounded flower heads; spec. any of several varieties of hydrangea, esp. Hydrangea macrophylla (‘Hortensia’…