Pistia is a genus of aquatic plant in the family, Araceae. The single species it comprises, Pistia stratiotes, often called water cabbage, water lettuce, Nile cabbage, or shellflower. it was first discovered from the Nile near Lake Victoria in Africa. The flowers are dioecious,(i.e. male and female parts are found on different plants.) and are hidden in the middle of the plant amongst the leaves. Small green berries form after successful fertilization.