Flower:

A single flower 1 to 2½ inches across on a stout stalk rising above the water. Flowers are globular, typically with 3 round bright yellow petals that may be green on the outer surface near the base, and dark red on the inside near the base, with 3 smaller green sepals separating the petals. In the center are numerous yellow stamens around a yellow central column, with a ring of stigma protruding at the top.

Leaves and stems:

Leaves are oval to heart-shaped, 4 to 10 inches long and about 2/3 as wide, with a rounded tip and deep cleft at the base, the lobes at the base are rounded and about half as long as the rest of the blade. The leaf stalks are flattened on one side, and are narrowly “winged”. Leaves are flat and float on the surface, but in low water conditions they rise above the water and can become wavy around the edges.

Notes:

Yellow Pond-lily is one of the more common aquatic plants in Minnesota, found in most counties, though surprisingly there are no herbarium records collected in places where it should be thriving, such as Sherburne and Rice counties. It often co-habitates with white water-lily (Nymphaea odorata). There is some debate over the accepted latin name of Yellow Pond-lily. Some references list it as Nuphar lutea spp. varietata, in fact, several Nuphar species were moved to subspecies of Nuphar lutea though I have not found any reference that explains why. Flora of North America, our definitive reference, does not list it as such so we are sticking with Nuphar variegata.