Water lettuce
Quick Facts
- Scientific name: Pistia stratiotes
- Origin: South America
- Introduction:Colonial period, ship ballast (?)
- Aquatic community: Floating
- Habitat: Water surfaces
- Distribution: Peninsula, rare in panhandle
- Management effort: Maintenance control
- 2020 Acres Treated: 25,266*
(*acres of water hyacinth and water lettuce combined)
Environmental and Economic Concerns
- Growth rate similar to water hyacinth – can double in a few weeks
- Reproduce by seeds and stolons
- Harbors mosquitoes
- Dense mats prevent air and light diffusion into water, consume oxygen
- displacing native plants, fish and wildlife
- preventing decomposition of detritus
- Increases sedimentation by shedding roots, leaves and shoots
- Rapid dispersal by wind and water movement
- Mats jam against bridges and reduce water flow at flood control structures
- Reduces property values and local tax revenues
Management Options
- Biological: 2 host-specific insects (ineffective to date)
- Chemical: Diquat, flumioxazin; carfentrazone Occasionally copper near drinking water intakes
- Mechanical: Harvest around bridges and flood control structures
- Physical: Occasional winter drawdowns (drying and desiccation)