White yam, white yam, also known as Japanese long lines. Ancient times yam yam, mountain medicine "argument. White yam as a health food in China for at least 2,000 years of history, "Shen Nong's Herbal Classic" was published in the Eastern Han Dynasty more yam as a top grade. Spleen and stomach, lower blood pressure and blood sugar, resist tumor, anti-aging effects, Vegetables beneficial to health. Geographic distribution of monocots, 10 genera and 650 kinds, widely distributed in temperate and tropical regions of the world, China Dioscorea genus Dioscorea 1 genus, about 80 species. Origin of Pingyao in Shanxi Jiexiu, now located in the north, northwest, and the Yangtze River in Jiangxi, Hunan and other areas of China. Home yams, wild sweet potato growers said said Wild Yam; herbal medicines known as yam, yam and medicine, Chinese yam. Because of its nutrient-rich, since ancient times as inexpensive tonic to share both primary grain and vegetables, can also be made of candied fruit snacks. Cultivated in our country is mainly produced in the northern part of Henan Province, Shandong, Hebei, Shanxi and South, Southwest and other regions. Winter stems and leaves wither after excavation, cut roots head, wash and dry.