Cyperaceae Eleocharis dulcis (Burm. f.) Trin. ex Henschel, Trapa natans L.
Source: Magness et al. 1971
Two types of aquatic plants are grown under the name water chestnut: One, E. dulcis, is a rush-like plant grown extensively in China for its near round turnip-shaped tubers. They are grown in ponds, and the tubers are harvested by scooping them off the bottom with forks. The other plant also called water chestnut, or Jesuit nut, or Water caltrops, is T. natans, a water plant with large leaves that float on the water surface. This is the water chestnut or "ling" widely used in Chinese foods. It is grown to some extent in Southern Europe and Asia. The edible part is the nutlike fruit, 1 to 2 inches in diameter, with 4 spined angles, which grows below the leaf blade. It is roasted and eaten like chestnuts. Neither type of water chestnut is produced commercially in the U.S., although there has been some effort with E. dulcis.
Production in the U.S.: No data. Negligible.
Use: Cooked, eaten out of hand, or in other foods.
Parts consumed: Tuberous bulbs in E. dulcis; nut-like fruits in T. natans.