From: Michigan State University Extension
What is European frog-bit and how did it get to Michigan?
European frog-bit (Hydrocharis morsus-ranae) is a free-floating aquatic plant with multiple miniature lily pad shaped leaves. This prolific invasive species is spreading along the shorelines and wetlands of Lakes Erie, Huron and Ontario. European frog-bit was brought from Europe to the Central Experimental Farm in Ottawa in 1932 as an ornamental plant. By 1939, it had escaped and spread to the Rideau Canal in Ottawa, Canada (Catling and Dore, 1982). Since then it has continued to spread into several rivers, Lake Ontario, Lake Erie, Lake Huron and other inland waters. In Michigan, European frog-bit is now common along the coastline of Lakes Huron, Erie and Lake St. Clair where emergent vegetation like cattail and phragmites protect European frog-bit from waves and currents. Figure 1 displays the current Midwest Invasive Species Information Network (MISIN) European frog-bit locations in Michigan. It is important to note that at this time there are very limited sightings in Michigan’s inland waters and it would be good to stay that way.