Family: Lamiaceae

Origin, Description & Uses
Gmelina arborea, commonly known as gmelina, is a fast-growing deciduous tree native to South and Southeast Asia, including India, Sri Lanka, and parts of Southeast Asia. It typically reaches 50–100 feet in height and is recognized for its broad, spreading crown, large heart-shaped leaves, and showy yellow to orange flowers. Gmelina is widely planted in tropical regions as a timber tree due to its lightweight, workable wood, which is used for furniture, plywood, paper pulp, and construction. It is also valued in agroforestry systems for shade, erosion control, and as a windbreak, and has traditional medicinal uses in some cultures.

Risks & Threats
Gmelina arborea is considered a low-risk species in Hawaii and is not known to be invasive or cause significant ecological harm. While it grows quickly and can naturalize in some tropical environments, it generally does not exhibit aggressive spread or outcompete native vegetation under typical conditions. Its reproduction and dispersal are relatively manageable, and it does not form dense, dominant stands. As with any introduced species, responsible planting and monitoring are recommended, but overall, gmelina poses minimal threat to Hawaii’s native ecosystems and is considered a suitable option when non-invasive trees are desired.

High Risk Traits:

• Naturalized outside native range (e.g., Cook Islands, Puerto Rico, Australia)
  
• Congeneric weeds exist (e.g., G. elliptica is a serious weed in Australia)
  
• Creates a fire hazard in natural ecosystems (leaf litter)
  
• Tolerates a wide range of soil conditions
  
• Produces viable seed
  
• Intentionally dispersed by people (widely planted as a timber/ornamental tree)
  
• Bird-dispersed propagules
  
• Propagules survive gut passage (dispersed by cattle, birds, bats)
  
• Tolerates mutilation (coppices well after cutting)

Low Risk Traits:

• No spines, thorns, or burrs
  
• Not toxic to animals or humans
  
• Not shade tolerant (requires full sunlight)
  
• Does not form dense thickets naturally
  
• No vegetative fragmentation
  
• Minimum generative time is 4+ years (slower reproduction)
  
• No unintentional dispersal (no produce contaminant, no wind/water dispersal, no external animal attachment)
  
• Not a prolific seed producer (<1000/m²)
  
• No persistent seed bank (<1 year)