What type of duckweed is there?

Duckweed primarily consists of three main genera: Lemna, Spirodela, and Wolffia. Lemna is the most common and includes species like Lemna minor, while Spirodela is known for its larger size, such as Spirodela polyrhiza. Wolffia species are the smallest flowering plants in the world. These types vary in size, shape, and ecological preferences, but all thrive in freshwater environments.