Dioscorea opposita is the dried rhizome of Dioscoreaceae. In winter, after the stems and leaves wither, they are hollowed out, cut roots, washed, peeled and fibrous roots removed, smoked with sulfur, and then dried. Or, select some fat and straight yams, soak them in clear water until there is no dry heart, suffocate them, smoke them with sulfur, cut off both ends, rub them into columns with boards, dry them in the sun and polish them, which is called "glory".
It has the effects of nourishing and strengthening, helping digestion, astringing deficient sweating and stopping diarrhea, and is mainly used for treating chronic enteritis such as diarrhea due to spleen deficiency, cough due to lung deficiency, diabetes, short and red urine, nocturnal emission, leukorrhagia and dyspepsia. Yam has a broad development prospect in food industry and processing industry.