clusters of filamentous alga spirogyra

stagnant waters lowland swamp filamentous algae seaweed carpets specific plants bogging paludification inundation imbibition waterlogging marsh water pollution boggy marshy bogginess eutrophication swamping vegetational fluctuation succession change green letch swampland purgatory marshland mire bog backwater fen morass slough spirogyra spirogira persicaria polygonum amphibium willow grass polygomtm weed amphibious ladys thumb enrichment hydrophytic plant aquatic layer stunted growth dwarfed clusters alga pond scum indicator fresh body cotton-like bubbles suppress