Flower:

A single flower 1 to 2+ inches (2.5 to 5.5 cm) diameter on a stout stalk rising above the water. Flowers are globular, typically with 6 round bright yellow petal-like sepals that may be green on the outer surface near the base, and dark red on the inside near the base. In the center are numerous yellow petals with dozens of similarly shaped stamens spirally arranged around a yellow central column. At the tip of the column is a yellow to greenish disk that has 7 to 28 rays.

Leaves and stems:

Leaves are basal, oval to egg-shaped, 3 to 14 inches (4 to 35 cm) long and half to 2/3 as wide, with a rounded tip and deep cleft at the base; the basal lobes are rounded and 1/3 to half as long as the blade's midrib. Leaf stalks are flattened on one side, and are narrowly “winged”. Leaves are typically flat and float on the surface, but in low water conditions can rise above the water and may become wavy around the edges.

Fruit:

Fruit is a somewhat pear-shaped capsule up to about 1½ inches (2 to 4.3 cm) long, strongly ribbed and usually purplish, fringed around the base with the remains of the stamens.

Notes:

Yellow Pond-lily, known in older references as Nuphar lutea spp. variegata, is one of the more common aquatic plants in Minnesota and found in most counties. It often co-habitates with White Water-lily (Nymphaea odorata). Yellow Pond-lily is readily identifiable by the large, yellow, globe-shaped flowers and large, oval, floating leaves. It is one of the parents to the hybrid Nuphar rubrodisca, which has slightly smaller flowers with a red disk.