Hydrangea macrophylla

Hydrangea macrophylla is a deciduous shrub widely cultivated for its large, showy flower heads that change color based on soil acidity. It is a popular ornamental plant with hundreds of cultivars, primarily divided into mophead and lacecap groups.

It is native and endemic to Japan, naturally occurring in coastal habitats from Honshu southwards. The species has naturalized in many parts of the world and is considered invasive in regions like the Azores and Madeira.

It is primarily valued globally as an ornamental shrub for gardens and landscaping. It is also noted for its low flammability, making it suitable for planting in building protection zones in fire-prone areas.

The fermented and dried leaves of the variety thunbergii are used in traditional Japanese herbal medicine as a preparation known as Hydrangeae Dulcis Folium. These leaf preparations have been historically utilized in folk remedies for various ailments.

In Japan, the hydrangea is closely tied to the rainy season and is traditionally said to symbolize heartfelt emotion, gratitude, or an apology. According to folklore, an ancient emperor gifted hydrangeas to a maiden's family to apologize for neglecting her.