Nuphar variegata (variegated pond-lily, bullhead pond-lily or yellow pond-lily) is rhizomatous, perennial, aquatic herb in the water lily family Nymphaeaceae native to much of Canada and the northernmost of the United States.
Nuphar variegata is a rhizomatous, perennial, aquatic herb with 2.5âÂÂ7 cm wide rhizomes. The leaves are submerged or floating, but most are floating leaves. The submerged leaves are 7âÂÂ35 cm long, and 5âÂÂ25 cm wide. The petiole is flattened.
The 2.5âÂÂ5 cm wide, yellow flowers float on the water surface or extend beyond it. The flowers have 6 yellow sepals which enclose the small petals. The gynoecium consists of 7âÂÂ28 carpels. The green to yellow, or rarely red stigmatic disk with 7âÂÂ28 stigmatic rays is 8âÂÂ20 mm wide. The fleshy, strongly ribbed, ovoid, 2âÂÂ4.3 cm long, and 2âÂÂ3.5 cm wide fruit bears 2.5-5 mm long seeds.
The chromosome count is 2n = 34.
It was first validly published by Elias Durand in 1866 based on previous work by George Engelmann. It is placed in the section Nuphar sect. Astylus.
Together with Nuphar microphylla, it forms the natural hybrid Nuphar ÃÂ rubrodisca.
The specific epithet variegata, from the Latin variegatus, means variously coloured.
The NatureServe conservation status is T5 Secure.
It occurs in ponds, lakes, streams, and rivers in up to 2 m deep water.