Nymphoides peltata

Nymphoides peltata (syn. Villarsia nymphaeoides, Limnanthemum peltatum S.G. Gmel., Nymphoides nymphaeoides (L.) Britton, fringed water lily, yellow floating heart, floating heart, water fringe, entire marshwort) is perennial, rooted aquatic plant with floating leaves of the family Menyanthaceae. N. peltata is native to East Asia and the Mediterranean. N. peltata has spread outside its native range and now occurs in North America, Ireland, Sweden, and New Zealand. In many of its introduced regions, N. peltata is considered a noxious weed because it can form dense mats that shade out native aquatic plant species, thereby reducing biodiversity, and also inhibit recreation....read more on Wikipedia.