Stock Photo - 12 April 2020, Brandenburg, Lebus: On the water of a lake in the Oder foothills, the area between the German-Polish border river Oder and the dike, reddish plants of the species Great Algae Fern or Fernlike Algae Fern (Azolla filiculoides) swim. The algae fern originally comes from the temperate to subtropical parts of America. In Germany, the species spread widely at the end of the 19th century. Thus, the Algae Fern is called an invasive neophyte, i.e. a plant that settles in places where it was previously not native. Photo: Patrick Pleul/dpa-Zentralbild/ZB. - Lebus/Brandenburg/Germany