The legend "Wu Gang conquered Gui" is quoted from "Youyang Zazu" of the Tang Dynasty. It is said that there is an osmanthus tree in the middle of the moon, five hundred feet high. Wu Gang, a native of Hexi in the Han Dynasty, did not follow the Tao because he was a follower of immortals. According to the regulations, he was punished to cut down the osmanthus in the middle of the moon. This tree will adapt to the cutting and will never fall. It will always be full of vitality. Every time during the Mid-Autumn Festival, the fragrance will overflow. In this legend, the moon and the osmanthus tree are two in one, and the osmanthus tree can survive. Like the moon, it symbolizes immortality.
Chairman Mao's poem "Asked Wu Gang what he had, Wu Gang brought out osmanthus wine" comes from this allusion.