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 |
| 2017 public waters / plant acres | 147 (32%) / 1,999 |
| 2017 Waters / acres controlled | Water lettuce 27 / 344 Lettuce / hyacinth mix 153 / 24,297 |
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) |
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
Florida Fish & Wildlife Conservation Commission, Status of the Aquatic Plant Maintenance Program in Florida Public Waters, Annual Report – Fiscal Year 2016-2017.