microscopic algae star duckweed or lemna trisulca or staurogeton trisulcus or schur or ivy-leaved duckweed. freshwater aquatic

algae america aquatic asia blunt closeup cooltemperate creek distributed duckweed europe floating flora free freshwater genus green greenery grow growth including lake leaves lemna long macro microscope microscopic nature oblonglanceolate oceania plants ponds regions rivers schur shape stalk star staurogeton submerged taillike taper trisulca trisulcus underwater water widely wildlife