: a plant of the genus Nymphoides; especially : a small white-flowered aquatic (N. cordata) with heart-shaped floating leaves
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1. any of certain aquatic plants belonging to the genus Nymphoides, of the gentian family, esp. N. aquatica, having floating, more or less heart-shaped leaves and a cluster of small, white, five-petaled flowers.
2. a related plant, Nymphoides cordata, of North America, having a cluster of white flowers and round or somewhat oval leaves that are purple beneath.
[1855-60, Amer.]
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floating heart,
an aquatic plant of the gentian family that has floating, heart-shaped leaves.
Useful english dictionary. 2012.