Water lilies have large, round leaves 8–16 inches across, each with a single V-shaped notch, and each with its own stalk. The leaves may be floating, elevated above the water surface, or submerged, depending on water level fluctuations. The large, showy flowers have many petals that are typically white to pink to violet; the center is often yellow. Blooms July–October. Leaves and flowers are attached to flexible underwater stalks that rise from thick, woody rhizomes (modified underground stems) on the pond or lake bottom.
Similar species: American lotus (Nelumbo lutea) has yellow to cream-colored flowers with a large central disk that resembles a showerhead. The leaves do not have a cleft. Spatterdock (Nuphar advena) has deep yellow, saucer- or globe-shaped flowers and oval or heart-shaped leaves, which are cleft.