aquatic weeds growing underwater with a green leaf floating on top of the water over them

alga algae aquatic background botanical botany brown chara circulation closeup curlyleaf environment eutrophication family floating flora fresh freshwater golden grass green growing growth habitat leaf marine milfoil natural nature organism outdoor outdoors plant plants pond pondweed poor potamogeton potamogetonaceae river sago scum slimy submerged submersed summer texture them top underwater vegetation water weed weeds wet yellow