thread algae on the water in the pond, green floating algae in the pond

grass grassland soil wetland green flower prairie field meadow plant tundra plain lawn vegetation leaf plateau pasture marsh thread algae water pond floating fadenalgen slime background texture ecosystem environmental surface swamp summer outdoor closeup pollution natural flora spirogyra botanical phytoplankton desmid close-up nature sea freshwater filamentous alga threads environment ocean lake color river hair chloroplasts shallow algology ecology phycology cladophora moss