Lemna valdiviana, commonly known as Valdivia duckweed, is a minute, free-floating aquatic perennial herb native to a wide range of freshwater habitats including ponds, marshes, slow-moving streams, and protected waters in the Americas. It forms dense mats on the surface of calm waters, which can be beneficial for water quality by reducing algae growth due to nutrient competition. Valdivia duckweed is one of the smallest flowering plants, with individual plants measuring just a few millimeters across. It reproduces rapidly, primarily through vegetative means, making it a highly efficient colonizer of suitable aquatic environments.

Valdivia duckweed is valued for its role in phytoremediation, as it can absorb heavy metals and other pollutants from water. It is also used in aquaculture and wastewater treatment systems. In cultivation, it requires stagnant or slow-moving freshwater and can tolerate a wide range of pH levels. While it prefers nutrient-rich waters, it can survive in lower nutrient conditions as well. However, due to its rapid growth rate, Lemna valdiviana can become problematic, potentially clogging waterways and outcompeting native aquatic plants. It is considered potentially invasive outside its native range, so gardeners should consult local regulations before introducing it to their ponds or water features.CC BY-SA 4.0