Family: Apocynaceae

High Risk Traits:

• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Thrives in tropical climates
  
• Naturalized on all the Hawaiian Islands (except Niihau and Kahoolawe), and widely naturalized elsewhere
  
• A weed of pastures, reducing forage due to toxicity
  
• Environmental weed, competing with native plants
  
• Other Gomphocarpus species have become invasive
  
• Toxic to browsing animals if eaten accidentally (but unpalatable)
  
• Sap toxic and allergenic to people
  
• Forms dense thickets
  
• Produces viable seed
  
• Hybridizes with other Gomphocarpus species
  
• Reaches maturity in <1-2 years
  
• Seeds, in mud, adhere to animal pelts, machinery and other vehicles
  
• Seeds spread as a contaminant of hay and chaff
  
• Seeds wind-dispersed
  
• Seeds and fruit are buoyant and able to be spread by water

Low Risk Traits:

• Unarmed (no spines, thorns or burrs)
  
• Ornamental and medicinal uses
  
• Self-incompatible
  
• Not reported to spread vegetatively
  
• Herbicides provide effective control
  
• A host plant of Monarch butterflies (Danaus plexippus)