Center For Aquatic And Invasive Plants

Plant Management in Florida Waters

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

Uruguayan waterprimrose

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

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