It's cuckoo crying blood. The beautiful azaleas are loaded with heavy cultural and historical accumulation, which endows them with beautiful legends: According to legend, in ancient times, Du Yu, the monarch of Shu, was assassinated and became a cuckoo. Cuckoo cried so sadly that he vomited blood. In the spring season, azaleas moan, and red azaleas are everywhere. People say that the flaming azaleas are dyed red by the azaleas' hematemesis, so there is "the blood where the azaleas crow into flowers" and "the bright red water drops reflect the summer moon, all stained with the blood of wronged birds." Among the poems, the most famous one is Du Fu written by the Tang Dynasty poet Cheng:
Rhododendron, what's the credit for resentment?
Suspicion is blood in the mouth, dripping on the flowers on the branches.
So azaleas have become synonymous with sadness and homesickness. Throughout the ages, many kind men and women have interpreted the story of cuckoo crying with their sad love, and azaleas have become the keepsake and witness of faithful love.