Hydrangea petiolaris

Hydrangea petiolaris, a climbing hydrangea (syn: Hydrangea anomala subsp. petiolaris), is a species of Hydrangea native to the woodlands of Japan, the Korean peninsula, and on Sakhalin island of easternmost Siberia in the Russian Far East.

Hydrangea petiolaris is sometimes treated as a subspecies of the closely related Hydrangea anomala from China, Myanmar, and the Himalaya, as Hydrangea anomala subsp. petiolaris. The Hydrangea anomala species differs in being smaller (to 12 metres (39 ft) ) and having flower corymbs up to 15 cm diameter. The common name Climbing hydrangea is applied to both species, or to species and subspecies.