Family: Oleaceae

Origin, Description & Uses
Noronhia emarginata, commonly known as Madagascar olive, is a small evergreen tree native to eastern Madagascar. It is valued as an ornamental tree for its dense canopy, glossy green leaves, and small fragrant flowers followed by dark olive-like fruits. The species is well suited to warm tropical and subtropical climates and is often planted in gardens, parks, and along streets as a shade tree or privacy screen. Its tolerance of drought, wind, and coastal conditions has contributed to its popularity in landscaping throughout the Hawaiian Islands and other tropical regions.

Risks & Threats
Madagascar olive is naturalized on Kauaʻi, Oʻahu, and Maui, and is potentially naturalizing on Hawaiʻi Island. While it remains a desirable landscape tree, it does possess traits that are cause for concern in Hawaii. The species produces abundant fruit that can be spread by birds and other animals into nearby natural areas, where seedlings may establish and spread. Dense growth may compete with native vegetation and alter habitat structure in sensitive ecosystems. Because of these concerns, caution is recommended when planting Madagascar olive to ensure that it will not negatively impact Hawaii’s native forests and tropical island ecosystems. Monitoring for unwanted spread and avoiding planting near natural areas are encouraged.

High Risk Traits:

• Naturalized in Hawaiʻi (Maui, Kauai, O'ahu and potentially Hawai'i)
  
• Forms dense, self-seeding stands in shade
  
• Tolerates wide range of soils (clay, sand, acidic, alkaline)
  
• Bird-dispersed (fleshy fruits)
  
• Intentionally spread by people (ornamental)
  
• Resprouts after pruning

Low Risk Traits:

• Not toxic, allelopathic, or parasitic
  
• No spines or thorns
  
• No fire hazard (low flammability)
  
• No vegetative spread in wild
  
• No wind or accidental dispersal
  
• Not a prolific seed producer