Water Chestnut (Trapa)
Water chestnuts are plants with nut-like seeds that are often used as food in the countries where they grow. T. natans is an annual kind from the south of Europe, which makes floating tufts of triangular bronzed leaves buoyed up in the water by their inflated stems. The submerged leaves are a different shape, finely divided and serve partly as roots.
The pretty white and purple flowers float about among the leaves, and are followed by peculiar fruits, with a hard shell and sweet white kernels, which have the flavor of a Spanish chestnut, and are good to eat either raw or cooked. Though it will grow out of doors in summer, the plant seldom comes to perfection with us, unless in water warmed by overflow from a hothouse tank or other means. A depth of about 2 feet is sufficient, and as they ripen in October the fruits reserved for seed sink to the bottom whence they rise of themselves on starting into growth in spring.
The seed is difficult to preserve in any other way, and unless quite fresh is seldom good.