Wild yam is a perennial twining herbaceous vine with a flowering period from June to August and a fruiting period from August to October. It grows on forest edges on hillsides, under shrubs and along ditches. Mainly produced in Liaoning, Jilin, Heilongjiang, Hebei, Inner Mongolia, Shanxi and Shaanxi. It is warm in nature, sweet and bitter in taste. It can relax muscles and activate blood circulation, relieve cough and reduce phlegm, expel wind and relieve pain. It is used for waist and leg pain, rheumatic pain, rheumatic joint pain, numbness of muscles and bones, Kashin-Beck disease, bruises, flashbacks, coughing and wheezing, tracheitis, and bronchitis. Pharmacological studies show that it has antitussive and asthma effects.

There are rust-like traces on the iron stick yam, so it is named iron stick yam. Tiegun yam is a precious Chinese herbal medicine that has been praised by doctors of all ages as a longevity factor and a good medicine and delicacy that can be used both as medicine and food. As a traditional Chinese medicine, it can be made into various pills, such as Liuwei Dihuang Pills, etc. for people to eat. As a food vegetable, it is delicate, smooth and has a unique flavor, such as shredded yam, jujube yam, etc. Tiegun yam contains saponins, mucilage, choline, saponin

Tiegun yam alkaloids, starch, glycoproteins, free amino acids, polyphenol oxidase, vitamin C, iodine, and 16 kinds of amino acids. There are also various trace elements such as iron, copper, zinc, manganese, and calcium.