Family: Arecaceae

The African Fan Palm (Borassus aethiopum) is a large, striking palm tree native to tropical Africa, from Senegal to Mozambique. It is easily recognized by its massive, fan-shaped blue-green leaves and a tall, grey trunk that can reach 20 meters in height. This palm is highly valued in its native range; its wood, leaves, and fibers are used for construction and crafts, while its fruits, shoots, and sap provide food and drink. It is also planted as an ornamental tree in landscapes for its impressive, tropical appearance.

While this palm has some traits that could be of concern—such as sharp spines on its leaf stalks and seeds that can be dispersed by mammals—its overall risk of becoming invasive is considered very low. The most significant factor limiting its spread is its extremely slow life cycle; it does not produce seeds until it is around 114 years old. Combined with its low seed production, intolerance of shade, and inability to form a seed bank, these characteristics make the African Fan Palm a minimal threat to native ecosystems in Hawaiʻi.

High Risk Traits:

• Native to tropical climates
  
• Congener is invasive (Borassus flabellifer)
  
• Has spines/thorns
  
• Broad climate tolerance
  
• Mammal-dispersed seeds
  
• Tolerates fire
  
• Tolerates browsing/mutilation
  
• Seeds survive animal digestion

Low Risk Traits:

• Not known to be weedy or naturalized
  
• Palatable to animals (fodder)
  
• Non-toxic
  
• Shade intolerant
  
• Limited soil tolerance
  
• Not self-compatible (dioecious)
  
• Extremely delayed reproduction (~114 years)
  
• Large fruit limits dispersal
  
• Low seed production
  
• No seed bank (short viability)