"Fairy children become flowers in the ground, the male is peony, and the female is peony." Where did this story come from?

Legend of Flower God: A pair of boys and girls dressed in red, with flowers in their hands, were chasing and playing. In an instant, peony and peony came out and sensationalized the four townships. Fairy boy fairy into flowers, male peony, female peony tie the knot regardless of left and right, saying they are lovers, saying they are husband and wife, word of mouth to this day.