The flowers of Nuphar are interesting. The outer whorl of the perianth is composed of 5 or 6 petal-like sepals. The inner whorl is represented by many small, thick structures that are transitional in appearance to the stamens. References: Wiersema and Hellquist (1997), Hellquist and Crow (1984).
This Genus’s Species in New England:
Visit this genus in the Dichotomous Key