Our mystery fern is native to Latin America and the Caribbean but, like so many other plant species, has found its way farther north. Is seems to be happy as part of the Florida flora, and rather recently has spread to Louisiana, and even central South Carolina. It can be found on the surface of quiet water of canals, lagoons or swampy places. Although in the U.S. it is not common outside Florida, it is conceivable that this species could indeed continue on a more northern track, and even pose a threat as an invasive aquatic weed. (Another species in the same genus already has reached that unhappy status.) Please, folks, if you are an aquarium owner, never consider dumping its contents into a nearby body of water; that’s how many, many pesky aquatic species (plants and critters) have ended up being problems for us. And, if you are a fisherman or otherwise find yourself plying the waters of our lakes and rivers, consider washing your boat and motor before hauling it to a different waterway.