Family: Myrtaceae

Origin, Description & Uses
Melaleuca leucadendra is a large evergreen tree native to the Maluku Islands of Indonesia and northern Australia. It is easily recognized by its pale, papery bark that peels in soft layers and its tall, spreading form with a somewhat weeping canopy. In its native habitat, it commonly grows in wet lowland areas, along rivers, floodplains, and seasonally inundated sites. The species is widely cultivated in tropical and subtropical regions as an ornamental shade tree, windbreak, and for landscape use. It is also valued for erosion control in wet soils, as well as for timber and aromatic essential oils (commonly called cajeput oil) that have traditional medicinal and topical uses.

Risks & Threats
Melaleuca leucadendra is generally considered a low-risk species and is not known to be a significant invasive threat in Hawaiʻi. While it can establish and grow well in suitable wet tropical environments, it does not show the same aggressive spread and ecosystem dominance seen in some related Melaleuca species. Even so, any non-native tree introduced into island ecosystems should be planted with care, as changes in water availability, disturbance, or favorable conditions could allow localized spread. Continued monitoring is recommended, but overall this species is considered relatively low concern for Hawaiian natural areas.

High Risk Traits:

• Congeneric (M. quinquenervia) is a serious invasive weed
  
• Native to tropical climates
  
• Tolerates a wide range of soil types
  
• Produces abundant viable seed (~2,300/g)
  
• Intentionally spread by people
  
• Water-dispersed propagules
  
• Prolific seed production (>1,000/m²)
  
• Tolerates fire and coppices readily

Low Risk Traits:

• No evidence of naturalization outside native range
  
• No documented weediness (garden, agriculture, or environment)
  
• No spines, thorns, or burrs
  
• Non-toxic to animals and humans
  
• No fire hazard
  
• Not shade tolerant
  
• No dense thickets
  
• No vegetative fragmentation
  
• Not dispersed by birds, animals, or produce contamination