Originally from Brazil, this free-floating fern has been introduced to the waters of Louisiana. The plant consists of three leaves covered with hairs that repel water. Giant salvinia is a small plant despite its name and is only giant when compared to common salvinia. Despite its size, both of these plants can blanket a waterway’s surface making it hard to access and shading out native vegetation. It is easily spread from one body of water to another because it tends to cling to objects like bird legs and boat trailers.