The yam is the most authentic yam produced in the ancient Huaiqing Province (in Jiaozuo City, Henan Province today), and it is known as Huaiyao yam or Huaiyama. Ancient doctors such as Sun Simiao, Zhang Zhongjing, Li Shizhen and other medicines must be differentiated by origin. Such as Colla Corii Asini to Shandong Dong'a, ginseng to Changbaishan Iron stick yam skin is earthy brown, with iron-red markings, slightly darker than other yam color. After steaming the iron stick yam, the inside yam meat is delicate in texture and slightly yellow in color; a look, observe the appearance of the yam. As mentioned earlier "" kiln land ", this kind of land in the most high-quality iron stick yam, characterized by curved, not straight enough, more small, general appearance. This is due to the harder soil of kiln land. At the same time, the appearance of the iron stick yam.

The length of the iron stick yam 50 to 60cm mostly, 80 to 90cm very few, looks ugly, convex a concave piece, curved, there are a lot of rust spots on the top, as thick as a thumb, too thick are not. The average person pinch not broken, vegetable yam a pinch on the broken yam has Huai yam and Huai yam points. The yam is a Taoist medicinal herb, produced in Henan Huaiqingfu (equivalent to the present Henan Xiuwu, Wuzhi west of the Yellow River, north of the Xinxiang area); Huai yam refers to the yam produced in the Huaihe River basin area, non-Taoist ingredients.

According to the Chinese Pharmacopoeia, there are two strains of iron stick yam, the Taigu yam and the Huai yam. Both texture is very hard, section white starch foot, are within fifty to seventy centimeters, and the tuber is not too thick. But there is a difference between the two. Iron stick yam is named because the skin like rust color, only Jiaozuo City, Henan Province, Wen County, the unique geographical location and climate can produce. Most businesses today claim that their yam is authentic iron stick yam, and today we teach you how to recognize the real and the fake.

A look: Iron stick yam diameter is usually 1 ~ 2 cm, uniform thickness, skin color dark, rhizome iron red mark. Second weighing: Iron stick yam single weight is generally not more than 200 grams.