Family: Apocynaceae

Origin, Description & Uses
Kopsia arborea is a tropical tree native to regions including southern China, Thailand, Vietnam, Indonesia, Malaysia, the Philippines, and Australia (Queensland). It grows up to 15 meters tall and produces ellipsoid, black or blue-black drupes. This species is found in a wide range of forest habitats, from sea level up to 1,500 meters, often as an understory tree or along forest margins. It tolerates various soil types and is occasionally cultivated as an ornamental plant in nurseries, such as in Florida. In traditional medicine, a decoction of its bark has been used as an enema, and leaves and fruit have been used to treat sore throat and tonsillitis.

Risks & Threats
Although Kopsia arborea is not currently known to be naturalized in Hawaiʻi, it does possess traits that are cause for concern. The fruit is highly poisonous, containing several novel indole alkaloids that are toxic to humans. The species has broad climate suitability, tolerates shade, and produces viable seeds that are dispersed intentionally by people (via horticultural trade) and naturally by birds, with seeds surviving passage through the gut. These characteristics could potentially allow it to spread if introduced. While there is no evidence of weediness or naturalization elsewhere, caution is recommended to ensure that it will not negatively impact Hawaiʻi. Ongoing evaluation is needed to determine whether this species could become invasive in Hawaiian ecosystems.

High Risk Traits:

• Broad climate suitability (wide range of forest types & soil conditions)
  
• Native or naturalized in tropical/subtropical regions
  
• Tolerates shade (understory tree)
  
• Toxic to humans (fruit contains indole alkaloids)
  
• Produces viable seeds
  
• Dispersed intentionally by people (ornamental sale)
  
• Bird-dispersed seeds
  
• Seeds survive passage through gut

Low Risk Traits:

• No evidence of naturalization or weediness
  
• No spines, thorns, or burrs
  
• No evidence of prolific seed production (>1000/m²)
  
• No evidence of persistent seed bank (>1 year)