Salvinia molesta

Salvinia molesta, commonly known as giant salvinia, or as kariba weed after it infested a large portion of Lake Kariba between Zimbabwe and Zambia, is an aquatic fern, native to south-eastern Brazil. It is a free-floating plant that does not attach to the soil, but instead remains buoyant on the surface of a body of water. The fronds are 0.5–4 centimetres (0.20–1.6 in) long and broad, with a bristly, waterproof surface caused by the hair-like strands that join at the end to form eggbeater shapes. The fronds are produced in pairs with a third modified root-like frond that hangs in the water. It has been accidentally introduced or escaped to countless lakes throughout the United States, including Caddo Lake in Texas, where the invasive species has caused eutrophication to occur. In Europe, Salvinia molesta has been included since 2019 in the European Union's List of invasive alien species of Union concern. Its inclusion means that the species cannot be imported, cultivated, transported, ......read more on Wikipedia.