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Center for Aquatic and Invasive Plants Logo    Plant Management in Florida Waters

Center for Aquatic and Invasive Plants Logo    Plant Management in Florida Waters

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

Uruguayan waterprimrose Uruguayan waterprimrose

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