Water lettuce

Quick Facts

Scientific name Pistia stratiotes
Origin – some debate native vs. exotic South America
Introduction Colonial period, ship ballast (?)
Aquatic community Floating
Habitat Water surfaces
Distribution Peninsula, rare in panhandle
Management effort Maintenance control
2014 public waters / plant acres: 168 / 2,954

Environmental and Economic Concerns

  • Growth rate similar to water hyacinth
  • Harbors mosquitoes
  • Mats prevent air and light diffusion into water
    • killing native plants, fish and wildlife
    • preventing decomposition of detritus
  • Increases sedimentation by shedding roots and shoots
  • Dense mats jam against bridges and reduce water flow at flood control structures
Pistia stratiotes Pistia stratiotes

Management Options

Biological 2 host-specific insects (ineffective to date)
Chemical Diquat; flumioxazin, occasionally copper near drinking water intakes; carfentrazone
Mechanical Harvest around bridges and flood control structures
Physical Occasional winter drawdowns (drying and desiccation)

Florida Fish & Wildlife Conservation Commission, Status of the Aquatic Plant Maintenance Program in Florida Public Waters, Annual Report – Fiscal Year 2009-2010.