Genus Wolffia is a genus in the family Lemnaceae, commonly known as watermeal or duckweed. This genus has only nine species, which are the world's smallest flowering plants. The size of the plant ranges from 0.6 to 2 millimeters, and they float on the surface of stagnant water. The common names for Genus Wolffia are wolffia, water meal, and duckweed. Other synonyms for Genus Wolffia are Lemna negundo, Lemna polyrrhiza, and Spirodela polyrrhiza. Wolffia arrhiza, also known as rosette watermeal or rooted duckweed, is another species of this genus. This genus plays a vital role in the ecosystem by removing excess nutrients from the water and providing food for aquatic animals.