Giant salvinia (Salvinia molesta)

An aquatic fern prohibited in the United States by Federal law. An invasive, rapidly growing plant that covers the surfaces of lakes and streams forming floating mats that shade and crowd out important native plants. Thick mats reduce oxygen content, degrading water quality for fish and other organisms, impeding boating, fishing and swimming, and clogging water intakes for irrigation and electrical generation. The plant spreads aggressively by fragmenting and has oblong floating leaves, 1/2 to 1 1/2 inches long. Young plants have smaller leaves that lie flat on the water surface. As the plant matures and aggregates into mats, leaves fold and compress into upright chains. For more information visit the Giant Salvinia website.