Plant Management in Florida Waters
Uruguayan waterprimrose
Quick Facts
- Scientific name: Ludwigia uraguayensis complex L. grandiflora & L. hexapetala
- Origin: South & Central America / Southern US
- Introduction: Mid-1880s, ornamental plant trade
- Aquatic community: Emergent
- Habitat: Wet soils to water a few feet deep floating mats
- Distribution: Peninsular Florida, especially Central
- Management effort: Eradicate new colonies Maintenance for established populations
- 2020 Acres Treated: 827
Environmental and Economic Concerns
- Rooted in the substrate in wet soils to several feet of water with rhizomes >15 feet long
- early creeping growth form aids dispersal; erect growth form covers / outcompetes native plants
- forms dense stands that can alter habitats and exclude native plants – also allelopathic
- Fragments drift into and colonize stands of emergent plants
- overgrow and outcompete other emergent plants
- dense floating / drifting mats crowd and shade out submersed plants
- restrict water flow and motor boat traffic
- Reproduction is primarily by fragmentation – also seeds
- fragments easily spread by boat traffic or water movement
- persistent rhizomes, leaf fragments and rapid growth make control extremely difficult
- L. grandiflora and L. hexapetala freely hybridize
- individual species and hybrids appear similar, but respond differently to different herbicides
- varying hybrid appearance and herbicide susceptibility add to difficulty in control
Management Options
- Biological: None available
- Chemical: Imazamox, Carfentrazone, Glyphosate, 2,4-D, Imazapyr
- Mechanical: Harvest mature mats – fragments likely start new infestation. Extreme biomass leads to high harvest and disposal costs
- Physical: Not feasible due to extensive rhizomes