PO Box 419

Hotchkiss, CO 81419



fax: 720-880-3051



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: True Ferns (Salviniaceae)


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




Legal Status: Colorado Noxious Weed List A



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



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 and spores


Dispersal: Water movement, animals, man, and equipment




Jacono, C.C. The Biology of Salvinia sp., Internet: 7/29/04, Available:

Jacono, C.C., USGS, Internet: 2/25/03 Available:



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