Giant salvinia (Salvinia molesta)

Category A Weed

Salvinia family (Salviniaceae)

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  • Floating aquatic plant that grows at water surface; often highly branched


    • 1 submerged and 2 floating leaves whorled around stem at each node

    • Floating leaves are oval, flat, 1-2.5 in. wide and covered with short hairs (less than 0.12 in. long) that are shaped like an egg-beater

    • Submerged leaves are white to brown, fine, hair-like, up to 1 in. long and resemble roots


      • No true flowers; some submerged leaves develop spores, but they are not viable


        • No true roots, but submerged leaves act as roots


          • Grows best in areas that do not experience extended periods of freezing temperatures; not known to occur in Nevada

          • Perennial; reproduces by stem fragments; can form a mat over 1.5 ft. thick under favorable conditions

          • Listed on the Federal Noxious Weed List


            • Mechanical removal can be effective but must be done repeatedly; escaped stem fragments can form new plants

            • Aquatic herbicides such as 2,4-D, diquat and fluridone are effective


              Giant salvinia Hairs on leaves
              Giant salvinia Hairs on leaves
              Hairs on leaves
              Giant salvinia Floating leaves
              Floating leaves
              Giant salvinia Submerged leaves
              Submerged leaves
              Giant salvinia Plant
              Nevada Noxious Weed Field Guide
              Nevada Noxious Weed Guide