Floating Watermoss

Other Common Names: eared watermoss, floating fern, water butterfly wings

(Salvinia natans)


Floating watermoss has two upper lobes that are hairy and a lower lobe that acts like roots. The rows of opposite lobes form a cross shape on the water.


Fragile rhizomes can grow to nearly eight inches long and are horizontal. This plant floats in the water with two opposite lobes that can grow to three-fourths of an inch long and a half inch wide. These bright green lobes are oval shaped and have lots of tiny bristles on them. The third lobe is highly dissected and acts like roots under the water’s surface.


This floating watermoss grows best in sunny humid areas where the water is calm. It is typically a water garden plant. It forms cross like shapes with its rows of lobes all lined up next to each other. Floating watermoss grows rapidly from fragments, creating large mats on the surface of the water. This can outcompete or shade out native species.


Floating watermoss has been found in the northeastern United States, Minnesota, and Florida.