Eleocharis dulcis (English name: water chestnut, scientific name: Eleocharis dulcis), also known as water chestnut, water chestnut, peony, water chestnut, black taro, water chestnut and pear, belongs to monocotyledonous Cyperaceae, and is a perennial herb with oblate shape and sharp top. Because it is shaped like a horseshoe, people also call it horseshoe. Its appearance is like chestnut, not only in shape, but also in taste, composition and function. Because it is produced in mud, it is also called "ground chestnut".

Eleocharis tuberosa is purple and black in skin, white in meat, sweet and juicy, crisp and delicious, and is known as "underground Sydney". Northerners call it "Jiangnan Ginseng", which can be eaten raw as fruit and vegetables. It is a popular seasonal product.