Giand duckweed have much more than just this Healthy Greater duckweed, also known as American Duckweed. Its scientific name is Spirodela polyrhiza. It is great for taking toxins straight from the water. A great algae controller as it feeds on the same nutrients as algae and will out compete it! Grows very fast. Good for giving fish shade on those hot summer days. Can also be put in an aquarium. Prefers full sun to partial shade. Collection only ASKERN Doncaster