At one time, half of my aquatic plants in the pond were edible. The main things now, that are edible, though not in my pond right now but some will be in Spring, are cattails, lotus, water celery, water spinach(invasive species in Florida), water cress, and taro. I'm sure that there are others that I haven't listed that can be added. Remember, whether you get it in the wild or in your pond, clean it thoroughly.