Answer: There are many varieties of yam, and the common ones are common yam, fine-haired yam, ganoderma lucidum yam, yam, dahe taro, iron bar yam and hemp yam. Yam generally refers to ordinary yam, and Tiegen yam is a kind of yam, which is a fine product in yam, and it is named after the traces like rust on its surface. Ordinary yam is irregular in shape, very thick, with smooth skin and a lot of water; Iron-rooted yam has a round head and a pointed tail, with hairy whiskers on the epidermis and dense distribution of pimples, which is delicate and firm.

First, the difference between yam and iron bar yam

1, types of yam

There are many varieties of yam, such as common yam, fine-hairy yam, ganoderma lucidum yam, yam, yamato taro, iron stick yam, hemp yam, etc. Yam generally refers to common yam, and iron root yam is one of many varieties of yam, which is named after the traces like rust on its surface and is a fine product in yam.

2. What is the difference between yam and iron stick yam?

(1) Different shapes: The common yam is irregular in shape and very thick, with a thickness of four or five centimeters; The iron stick yam doesn't matter in length, with a round head and a pointed tail, and the thickness is about 1- 1.5 cm.

(2) The epidermis is different: the epidermis of common yam is smooth, with hairs and pimples scattered; Iron stick yam has purple spots on the epidermis, hairy whiskers and dense distribution of pimples. It should be noted that if yam is sorted, the hairy whiskers on it will fall off, which can not be completely used as a basis for judgment, so it can be judged from the pimples.

(3) Different texture: ordinary yam has rough texture and a lot of water, which will break when touched slightly, and water can be squeezed out by hand; Iron stick yam is very delicate and compact, and the fiber is very fine and firm, and it is not easy to break.

(4) Different taste: Ordinary yam is crisp no matter how it is cooked, and can be used to make refreshing dishes; Iron stick yam, whether steamed or boiled, tastes sweet and dry. It can be cooked in ten minutes and cooked for a long time.

Second, the value of yam

1, yam tuber contains crude fiber 3.48%, crude protein 14.48%, sugar 1. 14%, starch 43.7%, potassium 2.62%, phosphorus 0.2%, calcium 0.2% and magnesium 0. Among the 20 amino acids needed by human beings, yam contains 16.

2. The quality of iron stick yam will be different due to different planting places and different planting intervals. Among them, Dioscorea opposita produced in Huaiqing Prefecture since ancient times has higher medicinal value, which is recorded in Jiaozuo Zhi and Agronomy Series in Qing Dynasty. It is valuable in both edible and medicinal aspects. Shennong Materia Medica called Dioscorea, a sweet potato, whose medicinal root is also called Huai because its efficacy can be compared with ginseng.