Salvinia molesta or giant salvinia has been confirmed growing in the wild in Texas and Louisiana. Occurrences have been verified in several private ponds in Harris County, Texas (Houston area), in one pond in Montgomery County, Texas (north of Houston), and on both the Louisiana and Texas sides of Toledo Bend Reservoir. The only previous "wild" occurrence of giant salvinia was in 1995 from a pond in South Carolina where the plant was eradicated.

A native of Brazil, giant salvinia is considered one of the world’s worst weeds because of its rapid growth and resistance to chemical treatment (due to a system of leaf hairs that make it very resistant to wetting). Giant salvinia has been known to form mats of up to 96 mi², wind row to a depth of three feet, and out compete water hyacinth and hydrilla. Reported leaf doubling times are as short as 2.2 days. Because of its growth habit, giant salvinia can block navigation and cause severe water quality problems. Although it is actually a water fern, giant salvinia does not produce viable spores. Reproduction is vegetative allowing for its rapid spread with floating plant fragments and daughter plants quickly establishing new colonies downstream from infestation sites. The plant thrives in a wide range of trophic conditions using three different growth forms depending on if it is expanding into open water, growing in a heavy mat, or surviving under stressful conditions. Its lower and upper temperature limits for growth of 50 F and 108 F respectively indicate it is well suited to much of the southeast. Attached is a fact sheet developed for distribution in Texas.