Family: Fabaceae

Leucaena leucocephala, commonly known as haole koa, is considered invasive in the Hawaiian Islands. Originally introduced for agricultural purposes, fodder, firewood, erosion control, soil improvement, shade trees for coffee or cocoa plantations, and as a nitrogen-fixing plant, it has since spread aggressively in many areas. It thrives in a wide range of soil types, grows rapidly, and produces large quantities of seeds, which allows it to outcompete native species. Its dense growth can create monocultures, reducing biodiversity by displacing native plants and altering ecosystems. Due to these impacts, L. leucocephala is managed in some areas to prevent further spread.

High Risk Traits:

• Naturalized and weedy in many tropical regions
  
• Forms dense, monospecific thickets
  
• Environmental and agricultural weed
  
• Self-compatible and produces abundant, viable seed
  
• Seeds form a persistent seed bank (hard seed coat)
  
• Fast maturity (flowers within 1 year)
  
• Tolerates a wide range of soil conditions
  
• Nitrogen-fixing (can alter ecosystems)
  
• Regrows vigorously after fire, cutting, or coppicing
  
• Difficult to control with herbicides

Low Risk Traits:

• No spines, thorns, or burrs
  
• Not toxic to humans (leaves and seeds are edible)
  
• Highly palatable to grazing animals
  
• Not a shade-tolerant plant (requires light)
  
• Not dispersed by wind, water, or external animal attachment
  
• Limited bird dispersal (rare)
  
• Significant natural enemies present (e.g., psyllid, seed weevil)