Family: Myrtaceae

Origin, Description & Uses
Eucalyptus grandis (rose gum) is a fast-growing tree native to eastern Australia, where it naturally occurs in moist, coastal forests. It is a tall, straight-trunked species that can reach over 150 feet in height, with smooth, pale bark that sheds in patches and glossy green leaves. Rose gum is widely planted around the world in tropical and subtropical regions for timber, pulpwood, and fuelwood production due to its rapid growth and high wood yield. It is also used in reforestation projects and windbreaks, and occasionally planted as an ornamental shade tree.

Risks & Threats
Although Eucalyptus grandis is not currently known to be naturalized in the Hawaiian Islands, it possesses several traits that raise concern for tropical island ecosystems. Its rapid growth, high seed production, and ability to thrive in a range of environmental conditions increase its potential to spread beyond cultivation. Like many eucalyptus species, it may alter soil chemistry, compete aggressively with native vegetation, and contribute to increased fire risk due to its flammable oils and leaf litter. These characteristics could disrupt native habitats and watershed functions if the species becomes established.

High Risk Traits:

• Naturalized outside native range (South Africa)
  
• Environmental weed (invasive in South Africa)
  
• Congeneric weeds (other Eucalyptus species are significant weeds)
  
• Unpalatable to grazing animals
  
• Host for serious pathogens (e.g., myrtle rust)
  
• Tolerates a wide range of soil conditions (including saline and acidic)
  
• Produces viable seed
  
• Hybridizes naturally with other species
  
• Self-compatible (self-fertile)
  
• Short minimum generative time (2-3 years)
  
• Propagules dispersed intentionally by people (widely planted)
  
• Propagules adapted for wind dispersal
  
• Prolific seed production
  
• Benefits from mutilation (coppices vigorously)

Low Risk Traits:

• No spines, thorns, or burrs
  
• Not toxic to animals or humans
  
• Not shade tolerant
  
• Does not form dense thickets
  
• No vegetative reproduction
  
• No persistent seed bank
  
• No evidence of dispersal by water, birds, or animals