Origin and Distribution

Common salvinia is native to Asia.
  True
  False

Transportation

Common salvinia escaped from _____ before becoming established in the wild in the United States.
  A. zoos
  B. ponds and greenhouses
  C. aquariums
  D. boats
  E. none of the above
  F. all of the above

Environmental Impact

Common salvinia is dangerous to the environment because it:
  A. steals habitat from native plants and animals.
  B. limits water-to-air contact, preventing oxygen exchange.
  C. creates stagnant water that allows mosquitoes to thrive.
  D. blocks sunlight from penetrating the water, preventing photosynthesis in submerged plants.
  E. all of the above.

Economic Impact

Common salvinia mats can be so thick that they block waterways so boats cannot pass.
  True
  False

Control

Which of the following methods are used to help keep common salvinia under control?
  A. salvinia weevil.
  B. herbicides.
  C. mechanical harvesting.
  D. all of the above.
  E. none of the above.