The seeds of many plants have wings, such as elm, Ailanthus altissima and Acer truncatum. In the north, the seeds of Toona sinensis should fall naturally after maturity, much like the wings of insects. If there is a Toona sinensis tree nearby, it can be confirmed. Planting next year can breed Toona sinensis trees; Collecting, removing wings and accelerating germination can make delicious sprouts.