There are at least 46 species of the waterlily genus, Nymphaea, and more than 100 Nymphaea cultivars that are not considered native to Minnesota.
Non-native waterlilies (Nymphaea spp.)
 Native Substitutes:
 Control Methods  
Mechanical
 Chemical
 Biological
Small populations can be removed by digging. Entire underground tuber must be removed. Tubers that are not removed from the water may drift to a new location and regrow Non-native waterlilies are susceptible to control by aquatic herbicides. However, to date, the DNR has not attempted herbicide control of these exotics because they grow in close proximity to native waterlilies which would also be damaged by any herbicide application None

 

 
Appearance: Perennial, showy forb. Leaves: Floating or slightly emersed in shallow water. Round with "v-shaped" opening or cleft. Flower: Unlike native waterlilies which have white flowers (Nymphaea odorata) or yellow flowers (Nuphar variegatum), most exotic waterlilies have brightly colored flowers including pink, purple, and red. Exotics may also have white or yellow flowers and can be difficult to distinguish from native species. Individual flowers have numerous petals and may bloom all summer. Seed: Hybrid species may or may not produce viable seeds. Root: Fleshy, buried rhizome that can spread extensively.

Non-native waterlilies may invade ponds and lakes. Hardy species may expand and choke out native plants. Non-native waterlilies are legally sold as water garden plants but are occasionally illegally planted in public waters. Non-native waterlilies sold for water gardening may also contain "hitchhiker" exotics like harmful exotic submerged plants or zebra mussels. Therefore, even though some exotic waterlilies do not survive Minnesota winters, the more harmful "hitchhiker" exotics can be introduced to our lakes when nursery or mail order species are planted.

Legal Status: This plant is a regulated exotic species in Minnesota and is legal to purchase and possess, but may not be introduced into a free-living state, including public waters or other sites where the species is beyond the control of a person.
Exotic Species Program 2000. Harmful exotic species of aquatic plants and wild animals in Minnesota: annual report for 1999. Minnesota Department of Natural Resources, St. Paul, MN.