Family: Apocynaceae

Allamanda cathartica, also called golden trumpet, is a tropical evergreen native to Brazil. It grows as a vine but can be pruned as a shrub. This plant thrives in hot, humid environments. It grows quickly and up to about 20 feet. It is now naturalized in several places around the world and is regarded as an environmental weed in Australia. In the Hawaiian Islands, fruit and seed production may be limited or absent, but the plant can spread by vegetative means and can climb up and potentially smother other vegetation. It also produces sap that is poisonous to animals and people if ingested or that can cause dermatitis when in contact with bare skin. There is now evidence that it may be naturalized or naturalizing on Hawaii Island.

Description and Dispersal:

• An annual broadleaf evergreen with yellow flowers.
  
• Trumpet-shaped flowers have 5 overlapping petals.
  
• The leaves and stems are pubescent.
  
• The stems contain toxic sap.

High Risk Traits:

• Thrives and spreads in regions with tropical climates
  
• Naturalized in several places around the world, including Hawaii Island.
  
• Currently spreading in vacant, disturbed lots on Hawaii island, with the potential to become an environmental weed if it establishes in native habitat
  
• An environmental weed in Australia, particularly in rainforests of northern and central Queensland.
  
• Fruit, if produced, covered in numerous spines.
  
• Potentially allelopathic.
  
• Possibly unpalatable to browsing animals.
  
• Sap is toxic to animals and people if ingested. All parts of the plant may cause irritant dermatitis in susceptible persons.
  
• Tolerates many soil types.
  
• Climbing and smothering growth habit.
  
• Reproduces by seeds (although rarely in the Hawaiian Islands).
  
• Capable of spreading vegetatively by rooting stems and dumped garden waste.
  
• Seeds, if produced, dispersed by wind, water, and intentional cultivation.
  
• Stem fragments may be spread down waterways during floods.
  
• Coppices and regrows and repeated cutting.

Low Risk Traits:

• Grows best in high light environments (dense shade may inhibit spread)
  
• Reportedly self-incompatible.
  
• Reduced or absent fruit and seed production may limit accidental and long-distance dispersal.
  
• Herbicides may provide effective control.