Yellow Water Lily (Nuphar polysepalum)
Like some other water plants (including rice) the water lily gives off alcohol instead of carbon dioxide.
“The Indians called this plant wokas. Many Indian tribes, notably the Klamath Indians, depended heavily on the wokas for food. They annually trekked to the Klamath Marsh to await the ripening of the seeds. They danced and held ceremonies until the seeds were ripe, and then gathered the wokas in huge hand-made sacks. The women ground most of the seeds to powder and flour; some were roasted and eaten like popcorn.”–Elizabeth Horn, Wildflowers 1: The Cascades.
Compare to the northwest’s other water lily: Nymphaea odorata.