Family: Convolvulaceae

Origin, Description & Uses
Decalobanthus peltatus (commonly known as merremia) is a vigorous tropical vine believed to originate from the Indo-Pacific region, where it occurs widely across warm, humid climates. It has now spread to many Pacific islands, including Kauaʻi, where it has become naturalized. This fast-growing plant produces long, twining stems and broad, heart-shaped leaves that allow it to rapidly climb over shrubs and trees. It is sometimes planted as an ornamental groundcover or used for quick vegetation cover in disturbed areas, and in some regions it has had minor traditional uses, but it is best known for its ability to spread aggressively in suitable tropical environments.

Risks & Threats
Decalobanthus peltatus is naturalized in Hawaiʻi and possesses traits that are cause for concern, including extremely rapid growth, vigorous climbing ability, and the capacity to form dense mats that smother vegetation. It can blanket trees and shrubs, blocking sunlight, weighing down canopies, and eventually killing native plants by outcompeting them for light and space. On tropical islands like Kauaʻi, this behavior can significantly alter native forest structure and reduce biodiversity. Because of its invasive tendencies and potential to spread into natural areas, it could detrimentally impact tropical island ecosystems. When possible, choosing a low-risk or native alternative is strongly recommended to help protect Hawaiʻi’s unique environments.

High Risk Traits:

• Thrives in tropical climates
  
• Widely naturalized
  
• A disturbance adapted weed that can smother forestry trees and suppress native vegetation
  
• Related Merremia species have become invasive
  
• Tolerates many soil types
  
• Climbing vine capable of smothering other vegetation
  
• Tuberous
  
• Spreads by seeds and vegetative fragments root fragments resprout and stem fragments readily take root

Low Risk Traits:

• Shade-intolerant and may eventually be suppressed or overtopped by other vegetation
  
• Fodder plant
  
• Requires full sun
  
• Considered desirable in some areas for ability to suppress other weedy vegetation