Yellow pond-lily

Nuphar advena
Scientific classification
Kingdom:	Plantae
Clade:	Angiosperms
Order:	Nymphaeales
Family:	Nymphaeaceae
Genus:	Nuphar
Section:	N. sect. Astylus
Species:	N. advena
Binomial name
Nuphar advena (Aiton) W.T.Aiton
Synonyms
Nuphar lutea subsp. advena

Nuphar lutea subsp. advena

Nuphar advena (spatterdock or cow lily or yellow pond-lily) is a species of Nuphar native throughout the eastern United States and at least some parts of Canada, such as Nova Scotia. It is similar to the Eurasian species N. lutea, and is treated as a subspecies of it by some botanists, though differing significantly in genetics.

It is locally naturalized in Britain.

Spatterdock was long used in traditional medicine, with the root applied to the skin and/or both the root and seeds eaten for a variety of conditions. The seeds are edible, and can be ground into flour. The root is edible too, but can prove to be incredibly bitter in some plants.

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Wikipedia