CWMA

PO Box 364

Paonia, CO 81428

 

970-361-8262

fax: 720-880-3051


Email:contact@cwma.org

 

 

Giant Salvinia

(Salvinia molesta)

 

Keys to Identification

  • Giant salvinia is an aquatic fern that floats on the surface of the water in ponds, lakes, and slow moving creeks. It reproduces by spores.
  • It is not known to occur in Colorado at this time but it has been spotted in the past. It is thought that this plant was an accidental introduction to the US through the aquarium trade. It is important to not spread it so cleaning boats and other equipment is an important method of prevention.

Family: Salviniaceae (True Ferns)

 

Other Names: Kariba weed, African pyle, aquarium watermoss, koi kandy

 

USDA Code: SAMO5

 

Legal Status: Colorado Noxious Weed List A

 


Identification

Lifecycle: Perennial or annual

Growth form: Floating fern, herbaceous forb.

 

Flower: N/A

 

Seeds/Fruit: Spores produced in long chains of sporocarps found on the submerged leaves.

 

Leaves: Upper leaves green with white bristly hairs that are split and resemble eggbeaters. Submerged leaf brown, finely divided.

 

Stems: Horizontal stems float just below the water's surface.

 

Roots: Rootless

 

Seedling: N/A

 

 

Similar Species

Exotics: Salvinia auriculata, S. biloba, S. herzogii

 

Natives: none

 


Impacts

Agricultural: Clogs lakes, ponds, streams, irrigation ditches

 

Ecological: Forms a dense mat that shades the water. Changes the oxygen content of the water both by preventing surface exchange and decomposing material which accumulates on the bottom surface of the waterbody.

 


Habitat and Distribution

General requirements: Freshwater lakes, ponds, slow moving streams and rivers. Biomass can double in 7-10 days.

 

Distribution: Not presently known to occur in Colorado. Found in southern US states

 

Historical: Native to South America


 

Biology/ Ecology

Life cycle: Perennial or annual

 

Mode of reproduction: Vegetative fragmentation spores

 

Dispersal: Water movement, animals, man, and equipment

 

 

Integrated Management Summary

Freezing. Can survive periods of stress. Herbicides.

 

 

References

Jacono, C.C. The Biology of Salvinia sp., Internet: 7/29/04, Available:http://www.ceris.purdue.edu/napis/pests/gs/facts/bio.html

Jacono, C.C., USGS, Internet: 2/25/03 Available: http://salvinia.er.usgs.gov/html/identification.html

 

 

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