Family: Fabaceae

Acacia pendula, known as weeping myall, silver leaf boree, or myall acacia, is a small to medium-sized tree native to inland Australia. It is recognized for its graceful, drooping branches and silvery foliage, and is valued in its native range for shade, erosion control, and drought tolerance. Traditionally, it has been used by Indigenous Australians for wood, food, and medicine. Because it is hardy and adaptable, A. pendula has been planted as an ornamental and for land rehabilitation in dry regions.

In Hawaii and the broader Pacific, however, Acacia pendula poses risks if introduced or spread. Like many Australian wattles, it has the potential to naturalize, form dense thickets, and outcompete native plants. Its fast growth and tolerance for poor soils allow it to spread in disturbed areas, and once established, it can be difficult to control. Invasions by non-native acacias threaten native ecosystems by reducing biodiversity, altering fire regimes, and changing soil chemistry. Careful management and caution are advised before planting A. pendula in sensitive island environments.

High Risk Traits:

• Able to grow in temperate to subtropical climates
  
• Naturalizing outside native range in Australia
  
• Several Acacia species have become invasive
  
• Tolerates many soil types
  
• Forms pure stands and thickets in native range
  
• N-fixing tree (may alter soil chemstry)
  
• Reproduces by seeds and vegetatively by root suckers
  
• Self-compatible (but requires pollinators for pollen transfer)
  
• Seeds dispersed by gravity, water, internally by animals and intentionally by people
  
• Seeds able to be stored for extended periods; May form a persistent seed bank
  
• Able to coppice and resprout after cutting, browsing and fire

Low Risk Traits:

• No current reports of naturalization or invasiveness outside native range
  
• Unarmed (no spines, thorns, or burrs)
  
• Provides fodder for livestock
  
• Non-toxic
  
• Ornamental
  
• Slow growing (may take years before reaching reproductive maturity)
  
• Herbicides effectively control several other invasive Acacia species, and would presumably be effective if needed to control Acacia pendula