Hydrangea anomala, the Japanese climbing-hydrangea,[2] is a species of flowering plant in the family Hydrangeaceae native to the woodlands of the Himalaya, southern and central China and northern Myanmar.
It is a woody climbing plant, growing to 12 m height up trees or rock faces, climbing by means of small aerial roots on the stems. The leaves are deciduous, ovate, 7–13 cm long and 4–10 cm broad, with a heart-shaped base, coarsely serrated margin and acute apex. The flowers are produced in flat corymbs 5–15 cm diameter in mid-summer; each corymb includes a small number of peripheral sterile white flowers 2–3.5 cm across, and numerous small, creamy-white fertile flowers 1–2 mm diameter. The fruit is a dry urn-shaped capsule 3–5 mm diameter containing several small winged seeds.
The closely related Hydrangea petiolaris from eastern Siberia, Japan, and Korea, is sometimes treated as a subspecies of H. anomala; it differs in growing larger (to 20 m) and flower corymbs up to 25 cm diameter. The common name Climbing hydrangea is applied to both species.
