Hydrangea heteromalla is a species of Hydrangea flower, native to the Himalayas and China. Average height is 10'-15' with inflorescences that are 5"-8" across and bloom May-June,full flowering only occurs in full sun.Is a very adaptable plant that is hardy to USDA zones (4)5-7. This plant is seldom seen in American gardens although there is nice specimen at the Hillier Arboretum.