Giant salvinia (Salvinia molesta)

Stem

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

Leaves

• 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

Flower

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

Root

• No true roots, but submerged leaves act as roots

Other

• 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

Control

• 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