Click for a hub of Extension resources related to the current COVID-19 situation.
COVID-19 Resources

Giant Salvinia

Salvinia molesta



Giant salvinia is native to South America. It is a small free-floating plant that grows in clusters and develops into dense, floating mats or colonies in quiet water, undisturbed by wave action. The floating leaves of giant salvinia are oblong (0.5 to 1.5 inches long) with a distinct midrib along which the leaf may fold forming a compressed chain-like appearance. Salvinias have stiff leaf hairs on the upper surface of the leaves. In giant salvinia the leaf hairs have a single stalk that divides into four branches that reconnect at the tip, giving the hair a cage-like or egg-beater appearance. Underwater the leaves are modified into small root-like structures. The entire plant is only about 1 to 2 inch in depth. Salvinias are ferns and have no flower. Giant salvinia has sporangia but are thought to reproduce only by fragmentation. Giant salvinia can double in size in 4 to 10 days under good conditions. Giant salvinia is an aggressive invader species. If colonies of giant salvinia cover the surface of the water, then oxygen depletions and fish kills can occur. These plants should be controlled.

Dense salvinia colonies provide Habitat for micro invertebrates but if salvinia completely covers the surface of a pond it will cause oxygen depletions. These colonies will also eliminate submerged plants by blocking sunlight penetration. Salvinias have no known direct food value to wildlife and is considered an exotic and highly undesirable species.

This plant is not native to North America and it is illegal to possess or transport this species in Texas. Please report any sightings of this plant to Texas Park and Wildlife Department.

Giant Salvinia is a significant problem in Texas and throughout the Southern U.S.