floating garbage in a pond overgrown with floating duckweed and wolffia plants

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