Family: Myrtaceae

Origin, Description & Uses:
Eucalyptus deglupta, commonly known as rainbow eucalyptus, is native to tropical regions of Southeast Asia, including Indonesia, Papua New Guinea, and the Philippines. It is one of the few eucalyptus species naturally adapted to humid, lowland tropical environments. This fast-growing tree is widely recognized for its striking, multicolored bark, which peels away in strips to reveal vibrant streaks of green, blue, orange, and purple. It can reach impressive heights and features a straight trunk with a tall, open canopy. In Hawai‘i and other tropical areas, rainbow eucalyptus is commonly planted as an ornamental tree for its unique appearance, as well as for shade, windbreaks, and reforestation projects. It is also used in the pulp and paper industry due to its rapid growth.

Risks & Threats:
In Hawai‘i, Eucalyptus deglupta is naturalized on several islands and may continue to spread in suitable wet habitats. However, it is generally considered low risk compared to more aggressive invasive species. While it can establish in disturbed or managed areas, it does not typically form dense, invasive stands that outcompete native vegetation. Potential concerns include its large size, which may not be suitable for small landscapes, and the accumulation of leaf litter, which can affect understory plants. As with many eucalyptus species, it may also influence soil moisture and nutrient cycling. Overall, its impacts appear limited, but monitoring is recommended, especially in areas where it may begin to expand beyond cultivated settings.

High Risk Traits:

• Naturalized on Kaua'i, O'ahu and Hawai'i
  
• Broad climate tolerance (0–2500 m elevation; wide rainfall range)
  
• Widely planted across humid tropics
  
• Allelopathic
  
• Unpalatable to herbivores
  
• Tolerates varied soils (sand, clay, volcanic, limestone)
  
• Self-compatible
  
• Flowers in 3–4 years
  
• Actively dispersed by people
  
• Wind- and water-dispersed seeds
  
• Prolific seed production (~156,000 seeds/kg)

Low Risk Traits:

• Not a recognized weed
  
• No spines or thorns
  
• Shade intolerant
  
• No persistent seed bank
  
• Fire susceptible