Family: Myrtaceae

These species, both native to New Zealand, have the potential to be weedy as they are weeds elsewhere. To avoid future problems with Hawaiʻi’s health, economy and way of life, do not cultivate these species. M. kermadecensis has naturalized on Maui. Both are closely related to the native ‘Ohi’a Lehua (Metrosideros polymorpha) and look similar.

Description and Dispersal:

• Tree up to 60 ft with a trunk of 3 ft diameter, often grows a multi-trunked spreading tree
  
• Oblong, leathery leaves (3 in long) are covered underneath with dense white hairs
  
• Red flowers made up of a mass of stamens, similar to the native 'ohi'a's brush-shaped flowers
  
• M. kermadecensis differs from M. excelsa mainly by having smaller, more oval leaves and by flowering throughout the year
  
• Seeds spread by wind

High Risk Traits:

• Metrosideros kermadecensis is naturalized outside native range (Hawaiʻi, Norfolk Island, Lord Howe Island)
  
• Pest species on Maui and Category 4 weed on Lord Howe Island
  
• Congeneric (M. excelsa) is a declared weed in South Africa
  
• Repeated introductions outside native range
  
• Wind-dispersed seeds
  
• Prolific seed production (>1000/m²)
  
• Produces viable seed
  
• Broad climate suitability
  
• Highly suited to tropical/subtropical climates
  
• Palatable to grazing animals

Low Risk Traits:

• No spines, thorns, or burrs
  
• Not toxic to animals or humans
  
• Not shade tolerant (requires full sun)
  
• No vegetative fragmentation
  
• Not water-, bird-, or animal-dispersed
  
• No fire hazard