杜鹃花在我国的栽培历史悠久，在汉代就人工栽培。杜鹃花的名字来历，据说是古代蜀王（望帝）杜宇死后化为杜鹃鸟，夜夜悲啼，泪尽而滴血，落在花上，把花染红，化作殷红的杜鹃花。再加上杜鹃鸟嘴角有一红色斑纹
Rhododendron has a long history of cultivation in China, and it was artificially cultivated in the Han Dynasty at the latest. The origin of the name of Rhododendron is said to be that Du Yu, the ancient king of Shu (Wangdi), turned into a Rhododendron after his death. He cried sadly every night, shed tears and blood, fell on the flowers, dyed the flowers red and turned into a scarlet Rhododendron. In addition, there is a red stripe on the corner of the cuckoo's mouth
，恰似啼血滴滴。因此就用此命名，当然这只是一种传说。杜鹃花红的科学原因是，杜鹃花的细胞液里含有一种由葡萄糖变成的花青素。当花青素显酸性时，杜鹃花便呈红色。当它是碱性时，花便呈蓝色。
, just like crying blood drops. So it's named after it. Of course, it's just a legend. The scientific reason for Rhododendron red is that the cell fluid of Rhododendron contains a anthocyanin changed from glucose. When anthocyanins are acidic, rhododendrons turn red. When it is alkaline, the flowers are blue.