Comments: The taxonomic classification of the yellow pond-lilies (Nuphar) is currently unsettled; see the discussion by Wiersema and Hellquist (Flora of North America, vol. 3, 1997). Nuphar lutea was named from Europe, and is considered by some, including Beal (1956, J. Elisha Mitchell Sci. Soc. 72: 317-346) and Kartesz (checklist, 1994, and review draft checklist 8/98) to include as subspecies several North American taxa. On the other hand, the North American plants are often treated as several species instead (as by Wiersema and Hellquist in FNA). Appropriate nomenclatural combinations have not been made to allow treatment of the North American plants as subspecies of a North American species (excluding the European species Nuphar lutea). The Kartesz treatment is followed here, with synonymy provided for the names in FNA. Also, the gender of the generic name Nuphar has been debated; although often treated as neuter, it is considered feminine, with endings of scientific names corrected as needed. As treated here, Nuphar lutea ssp. lutea is a plant of Europe, Asia eastward to Manchuria and central Siberia, and southward to Algeria, Palestine, and Iran.