1, fried yam pieces can be cooked in 5 minutes if they are thinner, and it takes 6 to 8 minutes if they are thicker. Yam is a plant of Dioscorea in Dioscoreaceae, which is twined with herbaceous vines. Tubers are long cylindrical and grow vertically. Stems are usually purplish red, dextral, and glabrous. Simple leaves, alternate at the lower part of the stem, opposite above the middle part.

2. Male inflorescences are spikes, 2-8 cm long, nearly erect, and 2-8 of them are inserted in leaf axils. Capsule does not fold; The seeds are inserted in the middle of the axis of each ventricle. The flowering period is from June to September, and the fruit period is 7- 1 1 month.

3. Yam is distributed in North Korea, Japan and China; In China, it is distributed in Henan, south of Huaihe River in Anhui, Jiangsu, Zhejiang, Jiangxi, Fujian, Taiwan Province, Hubei, Hunan, Guangdong (Niutou Mountain in Zhongshan), Guizhou, northern Yunnan (Gongshan, Deqin and Lijiang), Sichuan, eastern Gansu and southwestern Shaanxi (350-1500m).