Family: Pontederiaceae

Origin, Description & Uses:
Kidneyleaf mudplantain (Heteranthera reniformis) is a small, creeping aquatic plant native to parts of the southeastern United States, Central America, and tropical regions of the Americas. It is typically found in shallow water, wetlands, ditches, and along pond edges, where it forms low mats of glossy, kidney-shaped leaves. The plant produces delicate, pale blue to lavender flowers that rise slightly above the foliage. Because of its attractive leaves and flowers, it is sometimes used in water gardens, aquascaping, or as a marginal plant in ponds and wetland restorations.

Risks & Threats:
Kidneyleaf mudplantain is naturalized on Oʻahu and possesses traits that are cause for concern in Hawaiʻi. It can spread rapidly through both seeds and vegetative fragments, allowing it to form dense mats that crowd out native wetland vegetation and alter habitat structure. These mats may reduce water flow, impact water quality, and interfere with habitat used by native aquatic species. Its ability to thrive in a range of wet conditions makes it difficult to control once established. Because of these risks, this species could detrimentally impact tropical island ecosystems. If intentionally cultivated, it is recommended to choose a low-risk or native alternative to help protect Hawaiʻi’s unique wetland environments.

High Risk Traits:

• Broad native distribution and able to thrive in tropical climates
  
• Elevation range may exceed 1000 m
  
• Naturalized in France, Greece, Italy; Portugal, Australia, Oahu (Hawaiian Islands)
  
• A disturbance adapted weed
  
• An agricultural weed in rice and taro
  
• Potential environmental weed
  
• Other Heteranthera species have become invasive
  
• Forms dense mats
  
• Spreads vegetatively and by seeds
  
• Can reproduce and spread from single pieces of stem or root fragments
  
• Seeds and plant fragments can be spread by water, birds, or stuck to machinery
  
• Can form a persistent seed bank

Low Risk Traits:

• Unarmed (no spines, thorns or burrs)
  
• Readily outcompeted and replaced by taller vegetation
  
• Does not thrive under shade
  
• Certain herbicides may provide effective control