leaf thickenings with air cells of a floating plant pontederia crassipes (eichhornia crassipes

eichhornia roots air cells floating plant alga algae aquatic araceae biomass closeup common duckweeds hyacinth water crassipes duckweed ecosystem flora foliage fresh freshwater green background flower invasive lake leaf leaves lemnaceae nature petal pond pontederia pool rootless seaweed spotless watermeal surface swamp tiny top view tropical weed