The Giant Salvinia

The Giant Salvinia plant (Salvinia molesta) is an invasive floating, rootless aquatic fern from South America that clogs the surfaces of freshwater lakes, canals, ditches and slow-flowing streams.

First discovered in Texas waters in 2007, giant salvinia has spread to 14 lakes, primarily in the eastern portion of the state where the acidic water suits its needs. It is most prevalent on Toledo Bend, where it covers at least 5,000 acres and on Caddo, where it was contained to about 100 acres last fall on the Texas side.

Untreated, salvinia can double the area covered in less than a week.

Giant salvinia has the potential to alter aquatic ecosystems in several ways. Rapidly expanding populations can overgrow and replace native plants. Resulting dense surface cover prevents light and atmospheric oxygen from entering the water.

Meanwhile, decomposing material drops to the bottom, greatly consuming dissolved oxygen needed by fish and other aquatic life.

Logically, the plant will continue to expand its reach in the U.S.


S. molesta range (2005)