Duckweed (IMAGE) University of Münster Caption Researchers took samples of duckweed from 68 waterbodies worldwide. Credit Klaus J. Appenroth Usage Restrictions Please use this picture only in connection with the press release. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.