There are 7 varieties of yam. They are common yam, fine-haired yam, iron-stick yam, yamato yam, ganoderma lucidum yam, Chinese yam and hemp yam. Among them, common yam is thick, with no rust spots on the surface and a lot of water, which is easy to rot after cooking for a long time.

The iron stick yam is thick and handsome, with many rusty spots on the epidermis and is more resistant to boiling. Dioscorea opposita is a specialty of Jiaozuo, Henan Province, with good quality and a famous brand.

morphological character

Iron stick yam is usually 2~2.5 cm in diameter, with a slightly darker skin and iron red spots on its roots. Weight: Generally, the single weight of iron stick yam is not more than 250g, that is, 500g, but the weight of iron stick yam in sandy soil over 80cm can be about 500g, depending on planting techniques and management.

When the iron stick yam is broken, it can be felt that its meat quality is hard, powdery and its cross section is delicate, white or slightly yellowish, with less mucus. The taste of iron stick yam is rich in polysaccharide and water, so its juice is thick. After cooking, it tastes dry and greasy, sweet and sweet, and eating with skin is accompanied by faint hemp taste.