Nymphoides is a genus of aquatic flowering plants in the family Menyanthaceae. The genus name refers to their resemblance to the water lily Nymphaea. Nymphoides are aquatic plants with submerged roots and floating leaves that hold the small flowers above the water surface. Flowers are sympetalous, most often divided into five lobes (petals). The petals are either yellow or white, and may be adorned with lateral wings or covered in small hairs. The inflorescence consists of either an umbellate cluster of flowers or a lax raceme, with internodes occurring between generally paired flowers.
Species of Nymphoides are sold as aquarium plants, including the "banana plant", N. aquatica and the "water snowflake", N. indica. Species native to the United States are N. cordata in the northeast and N. aquatica in the southeast. Nymphoides peltata is native to Europe and Asia, but can be found in the United States as an invasive aquatic weed. The non-native species N. cristata and N. indica also reportedly occur in Florida (Jacono 2000).
Numerous species of Nymphoides grow in Australia, and others exist in Africa, America, and Asia. There are approximately 50 species of Nymphoides.