Legend has it that in ancient times, there was a man who went out to war, and his wife leaned against the big tree on the mountain day and night to pray; I cried under the tree because I missed my lover in frontier fortress. When the tears dried up, bright red blood dripped out. Blood drops turn into red beans, take root and sprout, grow into trees and be full of red beans, which people call acacia beans. Day after day, I went to Qiu Lai in spring. The fruit of the big tree, along with the miss in the girl's heart, has gradually become the most beautiful red heart-shaped seed on the earth-acacia beans.