European Frogbit

European frog-bit (Hydrocharis morsus-ranae) is a free-floating plant that resembles a miniature version of water lily. Its small leaves are distinctly heart-shaped and its white flowers have three petals. Native to Eurasia, the plant can quickly form dense floating mats in wetlands and other slow-moving water systems.


Frog-bit prefers quiet, show-moving waters and can blanket shallow ponds, marshes and the edges of lakes. Like Eurasian water milfoil, frog-bit can reduce the growth of native submersed aquatic plants and has the potential to impact recreation.  Thick mats of frog-bit inhibit light penetration and hinder the movement of fish, waterfowl and boats. Viable plant fragments can spread by to new locations by boaters.


Leaves: thick, heart-shaped, 1 to 2 inches wide and smooth-edged with spongy, purplish-red undersides.

Flowers: small, showy flowers are ½ inch across, appear singly and have three white petals and yellow centers.

                                                                  European frog-bit, Hydrocharis morsus-ranae (Hydrocharitales: Hydrocharitaceae) - 5272031

Roots: 3 to 8 inches long and unbranched, dangling from the underside of each rosette of leaves.

Reproduction: can spread by sending out stolons which produce ‘daughter’ plants that break free and float to new locations. Also produces turions — compact winter buds that sink to the bottom in fall and float back up in spring to grow into new plants.


Plants can be collected by hand or mechanical harvesters, with all parts composted away from wetlands, rivers, or lakes. Care must be taken to prevent plant fragments from escaping the infestation site. Sites should be checked annually for reinfestations. Use of chemical herbicides also effective.

For more information:

Managing Invasive European Frogbit through Research and Education in New York’s Great Lakes Basin: A Project of the Finger Lakes Institute, Hobart and William Smith Colleges, Cornell University and Cornell Cooperative Extension of Onondaga County

Photo Credits: invasive.org Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

European Frogbit is an herbaceous aquatic
plant native to Eurasia. Frogbit does not root in the substrate and can quickly form dense floating mats in wetlands and other slow moving water systems. Like Eurasian water milfoil, frogbit can reduce the growth of native submersed aquatic plants and has the potential to impact recreation.

Prevent the introduction of invasive species into the SLELO PRISM.

Rapidly detect new and recent invaders and eliminate all individuals within a specific area.

Share resources, including funding personnel, equipment, information, and expertise.

Collect, utilize, and share information regarding surveys, infestations, control methods, monitoring, and research.

Control invasive species infestations by using best management practices, methods and techniques to include: ERADICATION (which is to eliminate all individuals and the seed bank from an area), CONTAINMENT (which is reducing the spread of established infestations from entering an uninfested area) and SUPPRESSION which is to reduce the density but not necessarily the total infested area.

Develop and implement effective restoration methods for areas that have been degraded by invasive species and where suppression or control has taken place.

Increase public awareness and understanding of invasive species.

Develop and implement innovative technologies that help us to better understand, visualize, alleviate or manage invasive species and their impacts or that serve to strengthen ecosystem function and/or processes.

Rob Williams
PRISM Coordinator

Megan Pistolese
Outreach and Education

Brittney Rogers
Aquatic Invasive Species

Robert Smith
Terrestrial Invasive Species