Family: Apocynaceae

Origin & Description:
Gomphocarpus fruticosus, or balloon cotton, is a shrubby plant from South Africa. It has narrow gray-green leaves, small star-shaped flowers, and unique balloon-like seed pods. It’s often grown in gardens for its ornamental appeal and to attract butterflies.

Risks & Threats:
This plant is not known to grow wild in Hawaii, but it can spread easily and form dense stands that crowd out native plants. Its seeds disperse by wind, and its toxic sap can harm animals. If introduced, it could disrupt local ecosystems, making it a high-risk species.

High Risk Traits:

• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Thrives in tropical climates
  
• Naturalized and rather common in northern Africa, southern Europe and eastern Australia
  
• A weed of pastures, reducing forage due to toxicity
  
• Environmental weed, competing with native plants
  
• Other Gomphocarpus species have become invasive
  
• Allelopathic
  
• Unpalatable
  
• 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
  
• Self-compatible
  
• Able to spread by suckering
  
• Reaches maturity in 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
  
• Able to resprout after cutting

Low Risk Traits:

• Unarmed (no spines, thorns or burrs)
  
• Ornamental and medicinal value
  
• Herbicides provide effective control
  
• A potential host plant of Monarch butterflies (Danaus plexippus)