Family: Cupressaceae

Origin, Description & Uses:
Cupressus sempervirens, commonly known as Italian cypress or Mediterranean cypress, is native to the eastern Mediterranean region, including parts of southern Europe and western Asia. This tall, narrow evergreen tree is well known for its striking columnar form, dark green scale-like foliage, and aromatic wood. Often associated with classic Mediterranean landscapes, it is widely planted as a vertical accent, windbreak, privacy screen, or formal hedge. Italian cypress is drought tolerant once established and thrives in sunny, well-drained locations, making it a popular ornamental tree in dry and coastal climates.

Risks & Threats:
Although Italian cypress is not currently known to be naturalized in the Hawaiian Islands, it possesses traits that raise concern for tropical island ecosystems. It produces numerous small seeds, tolerates a range of soil conditions, and can thrive in dry, disturbed, or rocky sites. In climates similar to its native range, it has shown the ability to persist and spread beyond cultivation. If it were to escape into natural areas, it could compete with native vegetation, alter habitat structure, and reduce biodiversity. Because island ecosystems are particularly vulnerable to invasive species, planting low-risk or native alternatives is recommended whenever possible to help protect Hawaiʻi’s unique natural environments.

High Risk Traits:

• Naturalized in multiple Mediterranean countries
  
• Broad climate suitability (zones 7B–11, wide elevation range)
  
• Congeneric weeds
  
• Highly allergenic pollen – significant human health risk
  
• Tolerates wide range of soils (clay, sand, alkaline, shallow)
  
• Wind-dispersed seeds
  
• Persistent seed bank (serotinous cones, seeds viable >5 yrs)
  
• Coppices after cutting or fire
  
• Host to multiple pests and pathogens
  
• Unpalatable to grazers
  
• Viable seed production

Low Risk Traits:

• Not an environmental, agricultural, or horticultural weed
  
• No spines, thorns, or burrs
  
• Not toxic to animals
  
• Does not increase fire hazard
  
• Not shade tolerant – unlikely to invade closed forests
  
• No vegetative spread