Definition of "waterlily"

Even the beloved paintings of the slowly evolving garden and lily ponds at his home in Giverny might have started out as rudimentary pencil and crayon studies, as a comparison of a blackish green, purple and blue painting of waterlilies, on loan from the Metropolitan Museum of Art, with a black crayon study from the sketchbooks suggests.

2007 August 10, Benjamin Genocchio, “Inside His Sketchbooks, Clues to Monet”, in New York Times‎