petiolaris), is a species of flowering plant in the family Hydrangeaceae native to the woodlands of Japan, the Korean peninsula, and on Sakhalin island of easternmost Siberia in the Russian Far East.

The Hydrangea anomala species differs in being smaller (to 12 metres (39 ft) ) and having flower corymbs up to 15 cm diameter.

[1] It grows up trees and rock faces in its native Asian habitats, climbing by means of small aerial roots on the stems.

Its outward-reaching side shoots can be pruned back to a pair of buds to espalier it flatter against its support.

[2] ‘Hydrangea’ is derived from Greek and means ‘water vessel’, which is in reference to the shape of its seed capsules.