Water shield, also known as water shield, water chestnut and lake vegetable, belongs to perennial aquatic herbs. Because it is rich in glial protein, carbohydrate, fat, vitamins and minerals, it has a good health care effect after long-term consumption. There are four big producing areas of water shield in China: Taihu Lake in Jiangsu, West Lake in Zhejiang, Luojishan in Sichuan and Lichuan in Hubei, among which Lichuan in Hubei is the most famous, so Lichuan is also named as "the hometown of water shield in China".