Family: Cupressaceae

Callitris columellaris, commonly known as white cypress pine or northern cypress pine, is a conifer native to Australia, where it occurs across a wide range of dry woodlands and open forests. It is a medium-sized, slow-growing tree with a straight trunk, fine, scale-like bluish-green foliage, and small, rounded woody cones. The pale, aromatic wood is naturally resistant to termites and decay, making it highly valued for fencing, outdoor structures, furniture, and interior woodwork. Because of its drought tolerance, neat form, and cultural significance in Australia, it is sometimes planted as an ornamental or windbreak in dry landscapes.

In Hawaiʻi and other Pacific islands, white cypress pine is not currently known to be invasive, but it has traits that warrant caution. Its tolerance of poor soils and dry conditions, along with long-lived seeds, means it could persist if planted in inappropriate settings. Large conifers can also alter light levels, soil moisture, and fire behavior, potentially affecting native plant communities if they escape cultivation. For these reasons, planting should be limited to managed landscapes, and care should be taken to avoid use near natural areas, especially dry or lowland habitats where native species are already under pressure.

High Risk Traits:

• Broad climate suitability
  
• Thrives in tropical climates
  
• Naturalizing on Oahu and Maui, Hawaiian Islands
  
• A potential agricultural weed which may reduce pasture productivity
  
• Other Callitris species have invasive tendencies
  
• Gum may be toxic if ingested. Pollen may be allergenic to susceptible individuals
  
• Tolerates many soil types
  
• Forms dense stands in native range
  
• Reproduces by seed, and possibly by suckering
  
• Seeds dispersed by wind, water and intentionally by people
  
• May seed prolifically in certain years (although not in excess of 1000 seeds m-2)
  
• Older trees may be resistant to fire. Younger trees are killed

Low Risk Traits:

• Unarmed (no spines, thorns or burrs)
  
• Palatable and non-toxic to browsing animals
  
• Reduces fire risk
  
• Relatively slow-growing. Reaches maturity after 6+ years
  
• Limited dispersibility of seeds
  
• Does not form a persistent seed bank