Family: Anacardiaceae

Origin, Description & Uses:
Schinus areira (California pepper tree, pepper tree) is native to South America, particularly Argentina, Bolivia, Peru, and neighboring regions. This evergreen tree is valued for its graceful, weeping canopy, finely divided foliage, and clusters of pink to red berries that resemble peppercorns. It has been widely planted in warm climates around the world as a shade tree, ornamental landscape specimen, and windbreak. The species is drought tolerant and adaptable to a variety of soil conditions, making it a popular choice in dry tropical and subtropical landscapes. In Hawaiʻi, it has been reported as naturalized on Hawaiʻi Island and is potentially naturalizing on Maui.

Risks & Threats:
California pepper tree is naturalized in Hawaiʻi and possesses several traits that are cause for concern. It produces abundant fruit that can be dispersed by birds and other animals, allowing it to spread beyond cultivation into natural and disturbed areas. The species is tolerant of drought, poor soils, and a wide range of environmental conditions, enabling it to establish persistent populations. Dense stands may compete with native vegetation for light, water, and space, potentially altering habitat structure and ecosystem processes. Because of these characteristics, California pepper tree could detrimentally impact tropical island ecosystems if its spread continues. Where possible, low-risk or native alternatives should be selected for landscaping and restoration projects. In areas where the species is already widespread, landowners and managers are encouraged to prevent further planting and manage existing populations near natural areas to minimize additional spread and ecological impacts.

High Risk Traits:

• Naturalized in multiple regions (e.g., California)
  
• Extensively introduced across >10 countries worldwide
  
• Listed as environmental weed in California (riparian habitats)
  
• Congener (S. terebinthifolius) is a major invasive weed in Florida
  
• Allelopathic (leaf and fruit extracts inhibit other plants)
  
• Wide soil tolerance (clay, sand, loam; acidic to neutral; drought and flood tolerant)
  
• Bird-dispersed seeds
  
• Seeds survive gut passage
  
• Widely planted as ornamental by people
  
• Fire-resistant (survives or recovers after fire)

Low Risk Traits:

• No spines, thorns, or burrs
  
• Non-toxic to animals
  
• No human allergen or toxicity reported
  
• No dense thicket formation
  
• No vegetative reproduction
  
• No unintentional dispersal (e.g., as contaminant)