Family: Myrtaceae

Origin, Description & Uses
Rhodomyrtus tomentosa (rose myrtle) is native to tropical and subtropical regions of Asia. It is an evergreen shrub that produces dense foliage, soft hairy leaves, and attractive pink to purple flowers, followed by edible purple berries. In its native range, it has been used ornamentally and occasionally for its fruit. In Hawaiʻi, it was introduced prior to 1920 on Kauaʻi and has since become naturalized across multiple islands, including Kauaʻi, Oʻahu, Maui, Lānaʻi, and Hawaiʻi Island. It is commonly found in disturbed areas, mesic to wet forests, and occasionally in bog margins between approximately 200–640 m elevation.

Risks & Threats
Rose myrtle is naturalized in Hawaiʻi and possesses traits that are cause for concern, including rapid growth, prolific fruit production, and the ability to form dense, persistent thickets. It can spread into disturbed forests and intact native ecosystems, where it may outcompete and displace native plants, reduce biodiversity, and alter habitat structure. Its fruits are readily dispersed by birds and other wildlife, contributing to further spread across the landscape. Because of these impacts, it could detrimentally affect tropical island ecosystems if left unmanaged. Where available, low-risk or native alternatives should be chosen in landscaping and restoration projects. In areas where it is already present but not yet widespread, efforts should focus on limiting planting and preventing further spread to reduce long-term ecological impacts.

High Risk Traits:

• Naturalized outside native range (Florida)
  
• Naturalized on Kauaʻi, Oʻahu, Lanaʻi, Maui, and Hawaiʻi
  
• Environmental weed in Florida and Hawaii
  
• Forms dense, nearly pure stands
  
• Fire-adapted; resprouts after fire
  
• Bird-dispersed seeds
  
• Intentionally spread by nurseries and gardeners
  
• Prolific seed production (dozens per fruit)
  
• Broad climate suitability (lowlands to 2700m)
  
• Propagates readily by seed

Low Risk Traits:

• No spines, thorns, or burrs
  
• No toxicity to animals or humans
  
• Not shade tolerant
  
• No vegetative spread
  
• Not dispersed by wind or water
  
• Well-controlled by herbicides (triclopyr)