Water Pennywort, Hydrocotyle spp, is an emergent pond weed. Other common names for this marshy plant include manyflower pennywort, dollarweed, and floating pennywort.

Hydrocotyle has rooted creeping stems. Stalks grow vertically from stems. At the top of the stalks are round green leaves with scalloped edges. Leaves are up to 2 inches in diameter.  

Dollarweed is found around the shorelines of ponds, lakes, streams and in marshy wetland areas. Vegetation can be found growing in shallow water. It can creep out into water and float at the surface. These floating mats aren't rooted in deeper water.

Marsh pennywort is native to some areas of the United States. This emergent weed provides food for waterfowl. It also provides habitat for invertebrates.

Propeller provides good control of water pennywort. Propeller flumioxazin is dissolved with water in a tank sprayer and then applied directly to vegetation.

Tsunami DQ is a fast acting herbicide for pennywort control. Tsunami diquat is mixed with water and surfactant in a tank sprayer and applied directly to weeds.

There are no effective natural treatment options for control of pennywort.