Authentic yam rhizome is slightly cylindrical and slightly flat, with a length of about 12 ~ 30 cm and a diameter of1.5 ~ 6 cm. The surface is yellowish white or light yellow, with longitudinal grooves and fibrous root marks. Heavy weight, solid texture, not easy to break, and the cross section is white powder. Odorless, light in taste, slightly sour, and sticky when chewing. Some are cylindrical, with flush ends and smooth surfaces, white or yellowish white.

2, rockery medicine

The appearance of rockery medicine is basically the same, and the cross section is white, but careful observation will reveal that the cross section is a small light spot, which is caused by internal fiber fracture. The middle part is sometimes hollow, tasteless, slightly sour and not sticky when chewed.

However, manufacturers of counterfeit drugs sometimes remove the middle part, especially the hollow part, which makes it more difficult to identify the authenticity. They can only confirm it by taste and powder. Counterfeit products are not as pink and sour as genuine products. Most of the counterfeit products in the market are processed from alfalfa roots, which are also powdery rhizomes, but have a small amount of fiber.

Extended data

Similar to yam, there are ginseng potato, strip potato, wild yam and sweet potato. These varieties are used locally and cannot be exported to areas that are not used for mixing with genuine yam. For example, ginseng potatoes once flowed into the pharmaceutical departments in Beijing and other places in large quantities.

Its appearance is very similar to that of yam, which is easily confused with genuine yam. In addition, in Beijing, sweet potatoes (also called sweet potatoes, sweet potatoes, etc.) are also found. ), a useful convolvulaceae plant, is sold as a rockery medicine. Its outer surface is sometimes covered with an unclean taupe or reddish skin, and its cross section is covered with yellowish tendons, which is sweet to chew. After investigation by the health department and the drug supervision department, these two varieties are quite different from the genuine products in microscopic characteristics.