Dioscorea oppositifolia L. (scientific name: Dioscorea oppositifolia L.) is a plant of Dioscorea in Dioscoreaceae, twining with herbaceous vines. The tuber is long and cylindrical, growing vertically. The stem is usually purplish red, right-handed, and hairless. Single leaf, alternate at the lower part of the stem, opposite above the middle. The male inflorescence is a spike like inflorescence, 2-8 cm long, nearly erect, with 2-8 inserted in leaf axils. Capsule does not retract; Seeds are born in the middle of the central axis of each compartment. The flowering period is from June to September, and the fruiting period is from July to November.
Distributed in North Korea, Japan, and China; Distributed in Henan, Anhui, Jiangsu, Zhejiang, Jiangxi, Fujian, Taiwan, Hubei, Hunan, Guangdong, Guizhou, northern Yunnan, Sichuan, eastern Gansu, and southern Shaanxi in China. It grows on slopes, under valleys and forests, in shrubs or weeds by streams and roadsides.
Tubers are commonly used traditional Chinese medicine "Huai Shan Yao", which are rich in starch and can be eaten by vegetables; Medication can replenish spleen and stomach losses, treat qi deficiency and weakness, indigestion, enuresis, enuresis, and nameless swelling. 
The first food to nourish the spleen and stomach is yam, which is a great choice for entering the lungs, strengthening the spleen, and tonifying the kidneys. The sticky juice of yam is mainly Mucoprotein, which can maintain the elasticity of blood vessels, and has the function of moistening the lungs and relieving cough. Chinese yam can be used with red dates to make porridge, soup or stir fry with various ingredients.
Medicinal: Dioscorea tubers are commonly used traditional Chinese medicine "Huaiyam", and their roots can be used as medicine. They are sweet, warm, gentle, and non-toxic. Indicating treatment for injuries, tonifying deficiency to win, eliminating cold and hot evil energy, tonifying the middle, benefiting qi and strength, growing muscles, and strengthening yin. Long serving, smart ears and eyes, light body, not hungry, prolonging life. This scripture. Master head and face swimming, dizziness in the head and eyes, lower qi, relieve back pain, treat deficiency and fatigue, win weight loss, replenish the five internal organs, and eliminate irritability and heat. Don't record. Repairing five pains and seven injuries, dispelling the cold wind, calming the mind, calming the soul, replenishing the lack of mental energy, and being open-minded and mindful. Zhen Quan. Strengthen muscles and bones, promote ejaculation and forgetfulness. Daming. Benefiting kidney qi, strengthening spleen and stomach, stopping diarrhea, resolving phlegm and saliva, moisturizing the skin and hair. Shi Zhen. The raw ramming paste is hard and swollen, and can dissipate the poison. Zhenheng.
Edible: Tubers are rich in starch and can be eaten by vegetables.