Chinese water chestnut Eleocharis dulcis, is not a nut and is a completely different plant from the water chestnuts of the genus Trapa. It is related to the European and African chufa. The ‘nut’ is really the corm of a kind of sedge. It resembles a gladiolus corm, round, flattened, usually between 2.5 and 5 cm (1–2") in diameter, and mahogany brown. As sold in the markets, it has rings of leaf scars on it.
This water chestnut is generally considered superior to Trapa nuts. It is peeled before use. The white interior can be eaten raw, out of hand as a snack or sliced into a salad, and is crisp with a pleasantly sweet and nutty taste. If cooked quickly it retains its crisp texture, which is the main quality for which the Chinese prize it.