Lemna is a genus of aquatic plants in the family Araceae. These plants are commonly known as duckweeds or water lenses.
Lemna plants are free-floating and have a very simple structure, consisting of a small leaf-like body called a frond that floats on the water surface. They have no roots, but they may produce short root-like structures called rootlets that serve to anchor the plants in place. Lemna plants reproduce asexually, producing daughter fronds that detach from the parent plant and float away to form new colonies.
In the aquarium hobby, Lemna plants are often used as a natural filtration system, as they are known to absorb nutrients and contaminants from the water. They can be used to help control algae growth and improve water quality in the aquarium. Lemna plants are also valued for their ability to provide shade and cover for fish and other aquatic creatures. They prefer calm, still water and can tolerate a wide range of water parameters. However, they can grow very quickly and may require periodic thinning to prevent overcrowding.