Hydrangea, also known as hydrangea and hydrangea, is a plant of the genus Hydrangea in the family Saxifrageceae.The flowers of Hydrangea are white, plump, large and beautiful. Their colors can range from red to blue, which are pleasing to the eye. They are common potted ornamental flowers and trees.Hydrangeas were cultivated earlier in China. Hydrangeas were planted in gardens in the south of the Yangtze River built during the Ming and Qing dynasties.