Also called Esthwaite waterweed and waterthyme.

Native to 🇪🇺 Europe, Asia, Africa and 🇦🇺 Australia.  Invasive > learn+quiz Invasive > Global Invasive > in USA+Canada Invasive > report it! Invasive > in Michigan

For kids!  This plant described in invasive species placemat series (print "Shrink oversized pages" or "Poster" or on 17"x11" paper).

Learn more about hydrilla Hydrilla verticillata

Biological Control in Eastern USA Discover Life Encyclopedia of Life Google Google images USDA PLANTS db Wikipedia