Stem

  • Floating aquatic plant that grows at water surface; often highly branched
Photo of giant salvina weed with green leaves
 

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
Photo of giant salvina weed with greent leaves.

 

Flower

  • No true flowers; some submerged leaves develop spores, but they are not viable
Photo of giant salvina weed with green leaves
 

Root

  • No true roots, but submerged leaves act as roots
Photo of giant salvina weed with green leaves
 

 

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 diquat and fluridone are effective 
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Nevada Noxious Weed Field Guide – Giant salvinia, Extension, University of Nevada, Reno, Field Guide

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