Potato, alias Shage, cold potato, sweet potato. Native to South China, Mexico, Central America and North America. It is widely planted in Sichuan, Chongqing and Taiwan Province provinces.

Doudou is an annual or perennial twining herb vine in Leguminosae, which can form tuberous roots. The tuber of sweet potato is plump, the meat is white, crisp and juicy, rich in sugar and protein, and rich in vitamin C. It can be eaten raw or cooked, so it is delicious. Rotenone (C23H22O6) is contained in seeds, stems and leaves, which is highly toxic to people and animals and can be made into pesticides such as dichlorvos.