The plant grows naturally along stream beds in mountain river valleys in Japan. Wasabi is generally sold either as a root (real wasabi), which must be very finely grated before use, or as a ready-to-use paste.Fresh leaves of wasabi can also be eaten and have some of the hot flavor of wasabi roots. They can be eaten as wasabi salad by pickling overnight with a salt-and-vinegar-based dressing, or by quickly boiling them with soy sauce. The leaves can also be battered and deep-fried into chips. Wasabi is often served with sushi or sashimi, usually accompanied with soy sauce.
Lotus: The flowers, seeds, young leaves, and "roots" (rhizomes) are all edible. In Asia, the petals are sometimes used for garnish, while the large leaves are used as a wrap for food.
Taro: Typical of leaf vegetables, taro leaves are rich in vitamins and minerals. They are a good source of thiamin, riboflavin, iron, phosphorus, and zinc, and a very good source of vitamin B6, vitamin C, niacin, potassium, copper, and manganese. Taro corms are very high in starch, and are a good source of dietary fiber
Water Caltrop: It was possible to buy water chestnuts in markets all over Europe until 1880. In northern Italy, the nuts were offered roasted, much as sweet chestnuts (Castanea sativa Mill.) are still sold today. At many places in Europe water chestnuts were known and used for human food until the beginning of the 20th century. Today, however, it is a rare plant.
Water Pepper: In Japan the leaves are used as a vegetable - it should be noted these are from the cultivar, not the wild plant, which has a far more pungent taste.
Wild Rice, Rice, Watercress, Water Spinach, Chinese Water Chestnut, Bulrush are also eaten able Food which grows in water.