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 importan