Why are the azaleas in Jinggangshan so red?

Rhododendron is a common species of Ericaceae, because it grows mostly in hilly and mountainous areas, and it is a kind of wild shrub with particularly tenacious vitality.

Jinggangshan has a famous "Ten-mile Rhododendron Natural Corridor". Every spring, on the steep ridge, azaleas in full bloom stretch out into the blue sky, reflecting the five hundred-mile Jinggangshan. When the rhododendrons in other places are shrubs, the rhododendrons in Jinggangshan are arboreal, each plant is as high as 15 meters, and the stem is about one meter. Flowers are pentagonal, as big as bowls and as small as buttons. Some trees have flowers of several colors.