Family: Myrtaceae

Origin, Description & Uses
Myrtus communis, commonly known as myrtle, is an evergreen shrub or small tree native to the Mediterranean region, western Asia, and parts of northern Africa. It is valued for its glossy dark green leaves, fragrant white flowers, and blue-black berries. Myrtle has long been cultivated as an ornamental plant in gardens and landscapes, especially in warm climates, and is often used for hedges, borders, and container planting. The aromatic leaves and berries have also been used in traditional medicine, perfumes, and culinary applications, including flavorings and liqueurs.

Risks & Threats
Although Myrtus communis is not currently known to be naturalized in Hawaii, it does possess traits that are cause for concern. The species produces abundant seeds, tolerates pruning and a range of growing conditions, and can persist in disturbed habitats. In some regions outside its native range, myrtle has shown the ability to spread beyond cultivation. Ongoing evaluation is needed to determine whether this species could negatively impact Hawaii’s ecosystems if more widely planted or dispersed. Careful management and monitoring are recommended to help prevent potential environmental impacts.

High Risk Traits:

• Possibly naturalized in South Africa and Australia
  
• Allelopathic properties
  
• Shade-tolerant
  
• Tolerates many soil conditions (and potentially able to exploit many different habitat types)
  
• Host of Puccinia psidii
  
• Self-compatible
  
• Fleshy fruited, with seeds dispersed by birds and mammals
  
• Can form a persistent seed bank
  
• Resprouts after fire

Low Risk Traits:

• Despite ability to spread, no negative impacts have been documented
  
• Unarmed (no spines, thorns or burrs)
  
• Palatable to animals
  
• Non-toxic
  
• Landscaping and ornamental value
  
• Timber tree
  
• Long time to maturity (10-20 years)