1. Flowers with small inconspicuous yellowish petals, not fragrant; sepals (at least the inner ones) bright yellow, showy; blades of floating or emersed leaves elliptic in general outline, the lobes rounded, with more pairs of veins arising from along the midrib than at its base; basal submersed leaves (often gone by late season) broad and membranous.
1. Flowers with showy white petals, usually fragrant; sepals green or reddish (paler inside); blades of floating leaves circular (or elliptic in one rare species) in general outline, the lobes pointed, with more pairs of veins radiating from base of midrib than from along midrib; basal submersed leaves none.
All species found in Nymphaeaceae
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. July 22, 2017. http://michiganflora.net/family.aspx?id=NYMPHAEACEAE.