Lemna minuta, commonly known as Least Duckweed, is a free-floating aquatic perennial herb. While its exact native range within the Americas is not well-documented, it is believed to inhabit calm freshwater habitats such as ponds, marshes, and slow-moving streams. It is now naturalized in many parts of the world, including Europe, where it was first reported in Poland in 2007. The plant is diminutive, typically presenting as a single green translucent oval leaf in shaded conditions and forming pairs when exposed to full sunlight, each frond measuring no more than 2.5 mm in length. Least Duckweed reproduces rapidly, forming dense mats on the water surface.

Least Duckweed is valued for its ability to quickly cover the surface of water bodies, which can be beneficial in garden ponds to reduce algae growth by limiting light penetration. It is also used in wastewater treatment systems due to its nutrient uptake capabilities. However, care should be taken as it can become invasive outside its native range, potentially disrupting local aquatic ecosystems. In cultivation, it requires stagnant or slow-moving water and can tolerate a range of light conditions from full sun to shade. It is not particular about water quality, making it a low-maintenance option for water features. It has been found to become invasive in Belgium as an alien duckweed.CC BY-SA 4.0