The patterns made by the Salvinia molesta in amongst the waterlilies might be interesting, but it is a troublesome weed. When I was in Papua New Guinea many years ago the weed had almost totally choked the estuary of the Sepik River - to the extent that the villagers could not get their canoes out onto the river to fish. At the time scientists were using a small beetle to try and rid the river of this weed. It is a popular aquarium plant - and that is how it got into the Sepik and earn't it's nickname as the Missionary weed. No idea how it got into our lilypond here at Mapleton in Queensland though.
