Hydrangeaceae

Hydrangeaceae is a family of flowering plants in the order Cornales, comprising shrubs, small trees, and climbing plants native to temperate and subtropical regions of Asia, North America, and Europe. The family is best known for Hydrangea, whose garden cultivars feature large showy inflorescences that can be composed of sterile decorative florets and fertile flowers. Other well-known genera include Deutzia, a group of deciduous shrubs with abundant panicles of small flowers, and Philadelphus, the mock orange, prized for its fragrance. Less familiar but cultivated members include Kirengeshoma and Schizophragma, which contribute climbing and sprawling forms with ornamental blooms.

Morphology typically includes opposite, simple leaves that are often serrate, and a habit ranging from dense shrubs to climbers. Flowers are usually small but arranged in conspicuous inflorescences. In Hydrangea macrophylla, floret color can be influenced by soil pH, reflecting aluminum availability in the soil. The fruits are generally dry capsules containing seeds.

Ecology and cultivation notes indicate these plants prefer moist, well-drained soils and, depending on the species, partial shade to full sun. They are widely grown as ornamental plants for their flowers, foliage, and, in some climbers, attractive bark or winter structure. Taxonomically, Hydrangeaceae has seen revisions with molecular studies, but its core garden-relevant genera—Hydrangea, Deutzia, Philadelphus, Kirengeshoma, and Schizophragma—are consistently recognized in horticultural and botanical references.