lagoon surface completely covered by aquatic plants, one of them flowered

aires angiosperm aquatic arbuscula argentina azolla background botany buenos cabbage caroliniana covered ecosystem environmental fern filiculoides floating flora flower flowered freshwater fully green japonica lagoon lake lettuce lopez magallenica microphylla monocot monocotyledon natural nature perennial pinnata pistia plants pond purple salvinia salviniaceae shellflower spreading squamosa stratiotes summer surface texture vegetation vicente water