It is an enlarged bulb at the top of underground stolon, and also has a slender creeping rhizome, and a tuber is born at the top of the rhizome, which is water chestnut. Its shape looks a bit like a horseshoe, so some areas also call it a horseshoe. Its skin is purple-black, its meat is white, its origin is China, and now it is cultivated in many parts of the world with many varieties.

Water chestnut belongs to the stem, not the root. Also known as horseshoe, it refers to the bulbous stem of the genus Eleocharis in Cyperaceae. Its skin is purple-black, and when peeled off, it will reveal a white edible part. It contains carbohydrates, fats, protein and other nutrients, as well as trace elements such as phosphorus and potassium, as well as a variety of vitamins, so it has high edible value.