Common Yam Rhizome is the dried rhizome of Dioscorea opposita Thunb.(Fam. Dioscoreaceae). The drug is collected in winter when the stem and leaf are withered, deprived of root stock, washed clean and deprived of outer bark and fibrous root; fumigated with sulfur, and then dried. Otherwise thick large straight and dried rhizome is sorted, soaked in clean water until the central portion of the druggets wet and softened thoroughly, then fumigated with sulfur, cut two ends to smooth plane and rubbed on a board to become cylindrical in shape, dried in the sun and finally polished. It is known as"Guang Shanyao". ( Polished Common Yam Rhizome).

Action: To replenish the spleen and stomach, to promote fluid secretion and benefit the lung, and to strengthen the kidney and restrain seminal discharge. Rhizoma Dioscoreae (stir-fried with bran): To replenish the spleen and promote the stomach function.

Indications:Anorexia and chronic diarrhea due to diminished function of the spleen; cough and dyspnea due to diminished function of the lung; seminal emission, excessive leukorrhea, frequency of urination or diabetes due to deficiency condition of the kidney. Rhizoma Dioscoreae (stir-fried with bran): Diminished function of the spleen with anorexia, diarrhea and excessive leukorrhea.