Figure 1: Duckweeds are small aquatic plants that are widely distributed in nature and amenable to culturing in the lab. (a) Duckweeds growing in the Raritan Canal River, Piscataway, NJ, USA. This population of duckweed includes Wolffia, Spirodela, and Lemna. (b) The relative size of Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia in the order of phylogeny as compared to an American Quarter. (c) Sterile Spirodela polyrhiza grown in the Schenk and Hildebrandt basal salt medium.