Water pennywort – Hydrocotyle species
Water pennyworts are very common plants throughout Florida. They flower throughout the year. They have long, creeping stems that often form dense mats. The mats can creep out over or into the water, or they can grow on shore. Water pennyworts occur in and near ponds, lakes, rivers, and marshes throughout the state. A profusion of leaves and stems is characteristic of water pennyworts. The stems can grow to be many feet long. The circular leaves typically are about the size of a half-dollar, but can be much larger or smaller. The leaves are shiny green and leathery. The margins have blunted teeth. Long leaf stalks attach at the leaf centers, umbrella-like. Water pennywort’s flowers form delicate white or greenish umbels. An umbel is made of many flowers all attached at the same point. These two pennyworts are Hydrocotyle ranunculoides and Hydrocotyle umbellata. They look very much alike. The main difference is that Hydrocotyle umbellata leaves are circular. Hydrocotyle ranunculoides leaves are also round, but they are notched (or cut) almost to the center. Water pennyworts are common throughout Florida. Their circular leaves are on long stalks, attached like umbrellas. The leaves are shiny green and leathery. Their white or greenish flowers are in delicate clusters.
View the herbarium specimen image from the University of Florida Herbarium Digital Imaging Projects.
For brief control information, see Efficacy of Herbicide Active Ingredients Against Aquatic Weeds by K. Langeland, M. Netherland, and W. Haller.