top view green leaves of water lettuce floating on water surface. pistia stratiotes or water lettuce is aquatic plant. invasive

aquatic asexual background backyard cabbage calm clean decorative duckweed ecology environment evergreen fern floating flora flower garden grass green habitat invasive lake leaf lettuce natural nature nile organic outdoor pantropical peace photosynthesis pistia plant pond purity relax reproduction shellflower spa species spring stratiotes surface texture therapy tranquil tropical water weed wetland zen