spotless watermeal, rootless duckweed (wolffia arrhiza) and duckweed (lemna turionifera)

freshwater duckweed spotless watermeal rootless lemna wolffia closeup alga aquatic plant araceae common duckweeds floating flora fresh green background growth lake leaf leaves lemnaceae natural nature petal pond pool seaweed surface swamp algae tiny top view water arrhiza turionifera stagnant