Home : Nonnatives : Invasive Plant Management : Have you seen this plant? :

Have you seen this plant? Salvinia molesta?

Why Salvinia molesta is an environmental problem

This South American native is currently invading waterbodies in Texas and Louisiana and has the potential to invade ponds, lakes, and rivers across the South including Florida.  Its introduction into the United States is linked to the importation of aquarium plants as an accidental contaminate.  It has caused severe economic and environmental problems in many countries including New Zealand, Australia, and South Africa. 

Giant salvinia grows rapidly and produces a dense floating canopy on the surface of ponds, lakes, and rivers.  It aggressively spreads by vegetative fragments.  These floating mats of giant salvinia shade out native submersed vegetation and degrade water quality.  These mats also impede boating, fishing, swimming, and clog water intakes for irrigation and electrical generation.   

Giant salvinia has been found in Florida’s aquatic plant nurseries from time to time and it has been successfully contained and eradicated.  However, a recent infestation was discovered growing in the wild in the Naples area.  After extensive management efforts by state and local government agencies, giant salivina has not been found at this site for several months and may have been eradicated. 

Giant salvinia can be identified by its oblong floating leaves, ˝ to 1 ˝ inches long.  As the plants mature and aggregate into mats, leaves become folded and compressed into upright chains. The upper leaf surface has rows of hairs, split at the tips and rejoined to form a "cage" or "basket" (appears like tiny "egg beaters").  These hairs give a velvety appearance and repel water.  The "egg beater" hairs distinguish giant salvinia from common salvinia, which have leaf hairs with branches always free at the tips (see photos and illustration below).

"Egg beater" type of surface leaf hairs distinguish Giant Salvinia from the
 smaller common salvinia  (left photo, courtesy The Nature Conservancy)

How is Salvinia molesta introduced into a waterway?

Plants can be carried overland on anything entering infested waters.  Boaters and anglers can help prevent the spread of giant salvinia by removing all aquatic plants from propellers, intakes, trailers, and gear before leaving a launch area.  Giant salvinia may also be introduced with aquarium or water garden plants. 

If you have seen this plant in Florida, please immediately call 1-850-245-2809. 

Alerts and Circulars for Salvinia molesta:

Have you seen this plant? (Multiagency)

Salvinia molesta - Possiblily the World's Worst Weed (USACE)

Links for Salvinia molesta:

United States Geological Service (USGS)
The Nature Conservancy
Invasive Species.Gov