Yellow water Lily, Spatterdock, Nuphar polysepala, Nuphar lutea subsp. polysepala, Nymphaceae, Water-Lily Family is an aquatic species which Native groups used a root infusion as blood purifier and an analgesic for back pain. The root was used for protection during epidemics, and to treat stomach ulcers. Leaf poultice for pain, bites, and infections.