Nuphar variegata

Native

Shallow, protected waters. Sun to shade.

June to August

Yellow outside, yellow with reddish tinge inside

Up to 7′

This is a floating, perennial aquatic that rises up to 7′ from a large, spongy rhizome. The scar remaining on the rhizome after a leaf detaches forms a spiral.

The leaves are alternate, arising directly from the rhizome on long stalks. They are mostly floating, though occasionally submersed. The leaf stalks are flattened on the upper side and narrowly winged. The leaf blades are green, sometimes purple-tinged on the underside. They are egg-shaped to almost round, 4″ to 10″ long, 2″ to 7″ wide, 1.2 to 1.6 times as long as wide. The base is heart-shaped, with the two rounded lobes close together or overlapping. The cleft between the two lobes (sinus) is ⅓ to ½ the length of the midrib. The blade tips are usually rounded. The margins are untoothed. The upper and lower surfaces are hairless.

The inflorescence is a single flower, at or just above the water surface, at the end of a long stalk arising directly from the rhizome.

The flowers are 1⅓″ to 2″ wide and in the shape of a ball. There are usually 6, sometimes more, petal-like sepals. The sepals are oblong, concave, thick, green to yellow outside, yellow with a reddish base inside. The stigma in the center of the flower is disk shaped and green, rarely reddened.

Yellow pond lily (Nuphar lutea ssp. advena) leaf stalks are round or somewhat flattened on the upper side. The leaves are mostly held above the water surface, not floating. Leaf blade is arrow-shaped, not heart-shaped. The lobes are usually separated by a conspicuous triangular notch the length of the sinus, often at an angle of 90° or more. The sepals are rarely tinged with red. It does not occur in Minnesota.