Hydrangea is a woody plant belonging to the Hydrangea genus in the Hydrangeaceae family. The tree crown is spherical; Small branches thick, hairless; Leaves are oblong or broadly elliptical in shape, with thick and hairless petioles; The inflorescence is spherical or head shaped, with thick branches and attached soft hairs. The flowers are dense and pink, light blue, or white in color; The fruit is in the shape of a spinning top. The flowering period is from June to August. The original name of the hydrangea was "Eight Immortal Flowers". People saw that this flower looked like a hydrangea, so it was also called "hydrangea flower". Hydrangea originated in China and is now distributed in Fujian, Jiangxi, Guangdong, Hong Kong, and Yunnan Guizhou provinces. It is also found in Japan and Korea. It often grows in valleys below 1700 meters above sea level, in dense forests by streams, or under sparse forests on mountaintops, and is often cultivated near houses, temples, or courtyards.

Toothed Leaf Ash is a plant of the Hydrangeaceae family and the Ash genus. Shrubs, 1-3 meters high; The flower branches are 8-12 centimeters long. Leaves papery, ovate or ovate lanceolate, petiole 3-8 mm long, sparsely covered with stellate hairs. The inflorescence is 5-10 centimeters long, with many flowers sparsely covered with star shaped hairs; Flower buds are oblong in shape; Crown diameter 1.5-2.5 centimeters; The flower stem is 3-5 millimeters long; Calyx tube cup-shaped, lobes ovate, densely covered with yellow brown star shaped hairs along with the flower stem and calyx tube; The petals are white, narrowly elliptical in shape, with a sharp apex and a narrowed base. The outer surface is covered with star shaped hairs, and the flower buds are arranged in a closed manner inward; The outer stamen is 8-10 millimeters long, while the inner stamen is shorter; Anthers are oblong in shape.