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
2017 public waters / plant acres 64 (14%) / 280
2017 Waters / acres controlled 37 / 1,553
Uraguyan waterprimrose

Uraguyan waterprimrose

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

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

Florida Fish & Wildlife Conservation Commission, Status of the Aquatic Plant Maintenance Program in Florida Public Waters, Annual Report – Fiscal Year 2016-2017.