pistia stratiotes - swims among aquatic plants rootless duckweed (wolffia arrhiza) and duckweed lemna turionifera, pond

alga algae aquatic plants araceae common duckweeds duckweed floating flora fresh green background growth invasive species lake leaf leaves lemna lemnaceae natural nature nile cabbage petal pistia stratiotes pistieae plant pond pool rootless seaweed shellflower spotless watermeal surface swamp tiny top view water lettuce wolffia swims arrhiza turionifera