Stock Photo - Common duckweed or Lesser duckweed, Lemna minor. It's a floating freshwater aquatic plant, with one, two, three or four leaves each having a single root hanging in the water. As more leaves grow, the plants divide and become separate individuals. It reproduces mainly vegetatively by division. Flowers are rarely produced and measure about 1 mm in diameter, with a cup-shaped membranous scale containing a single ovule and two stamens. The seed is 1 mm long, ribbed with 8-15 ribs. Birds are important in dispersing L. minor to new sites. The sticky root enables the plant to adhere to the plumage or feet of birds and can thereby colonize new ponds. Is distributed throughout most of Africa, Asia, Europe and North America. It is present wherever freshwater ponds and slow-moving streams occur, except for arctic and subarctic climates. L. minor has been shown to remove heavy metals like Pb, Cu, Zn and As very efficiently from waters with non-lethal concentrations. Because heavy metals have carcinogenic effects in humans, persist long in nature and accumulate in living organisms, their removal from the environment is important. Is very suitable for bioethanol production. Portugal