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National Invasive Species Information Center
U.S. Department of Agriculture
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  2. Aquatic Invasives
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  4. Giant Salvinia

Giant Salvinia

Scientific Name

Salvinia molesta D. S. Mitch. (ITIS)

Common Name

Giant salvinia, kariba-weed

Native To

Brazil (McFarland et al. 2004)

Date of U.S. Introduction

1990s (McFarland et al. 2004)

Means of Introduction

Horticultural trade (McFarland et al. 2004)

Impact

Forms dense mats that block sunlight and reduce oxygen levels (McFarland et al. 2004)

Giant salvinia

Giant salvinia, plants

Credit

Photo by Scott Bauer; USDA, Agricultural Research Service

Source
Invasive.org.

Find more images

Spotlights

  • Fungus Fights Oxygen-Sucking Water Weed

    • Aug 12, 2019

    • USDA. ARS. Tellus.

    • In parts of the South, there are stories about an invasive floating weed, which forms such a dense mass that it enables small animals to walk across water. This weed, called giant salvinia, is an exotic fern from South America that invades ponds, lakes, and other waterways in the United States. It damages aquatic ecosystems by outgrowing and replacing native plants that provide food and habitat for native animals and waterfowl.

      Agricultural Research Service (ARS) scientists are testing a naturally occurring fungus (Myrothecium spp.) against giant salvinia to help control it. Initial tests have found that the fungus stops this problematic weed from growing and even can kill it.

Distribution / Maps / Survey Status

Federally Regulated

  • Noxious Weeds Program

    • USDA. APHIS. Plant Protection and Quarantine.

    • Includes species listed as a Federal Noxious Weed under the Plant Protection Act, which makes it illegal in the U.S. to import or transport between States without a permit.

Videos

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Selected Resources

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Citations