Nuphar lutea, the yellow water-lily, brandy-bottle, or spadderdock, is an aquatic plant of the family Nymphaeaceae, native to northern temperate and some subtropical regions of Europe, northwest Africa, and western Asia.

[3][4] This species was used as a food source and in medicinal practices from prehistoric times with potential research and medical applications going forward.

[5]: 30 Nuphar lutea is an aquatic, rhizomatous,[6] perennial herb[7] with stout,[8] branching, spongy,[9] 3–8(–15) cm wide rhizomes.

[17][18][9] Habitat for Nuphar lutea ranges widely from moving to stagnant waters of "shallow lakes, ponds, swamps, river and stream margins, canals, ditches, and tidal reaches of freshwater streams"; alkaline to acidic waters; and sea level to mountainous lakes up to 10,000 feet in altitude.

[20] This "ventilation mechanism" has become the subject of research because of this species' substantial benefit to the surrounding ecosystem by "exhaling" methane gas from lake sediments.

[21] Nuphar lutea plant colonies in turn are affected by organisms that graze on its leaves, gnaw on stems, and eat its roots, including turtles, birds, deer, moose, porcupines, and more.

[22] With other species in the Nymphaeales order, Nuphar lutea provides habitat for fish and a wide range of aquatic invertebrates, insects, snails, birds, turtles, crayfish, moose, deer, muskrats, porcupine, and beaver in shallow waters along lake, pond, and stream margins across the multiple continents where it is found.

Stone masons carved forms of the flowers on the roof bosses of Bristol Cathedral and Westminster Abbey, these are thought to encourage celibacy.