Family: Oleaceae

Origin, Description & Uses
Ligustrum obtusifolium (border privet, obtuse-leaved privet) is native to eastern China and Japan. It is a deciduous to semi-evergreen shrub commonly grown as an ornamental plant, especially for hedges and screens. It is valued for its dense growth habit, small oval leaves, and clusters of white flowers that can produce abundant dark berries. Because it tolerates pruning, pollution, and a range of growing conditions, it has been widely used in landscaping outside its native range.

Risks & Threats
Although Ligustrum obtusifolium is currently not known to be naturalized in the Hawaiian Islands, it does possess traits that are cause for concern, and which could detrimentally impact tropical island ecosystems. In other regions, privet species are known to spread aggressively through bird-dispersed seeds, forming dense thickets that crowd out native plants, reduce biodiversity, and alter habitat structure. Its shade tolerance and fast growth allow it to dominate understory environments, while its persistent seed production increases the risk of escape from cultivation. Given these characteristics, caution is warranted, and planting should be carefully reconsidered in favor of low-risk or Hawaiian native alternatives that support local ecosystems and biodiversity.

High Risk Traits:

• Grows in 5 hardiness zones in temperate climates, demonstrating environmental versatility
  
• Naturalized in at least 20 states in the continental United States (but no evidence in Hawaiian Islands to date)
  
• A garden and environmental weed on the mainland US
  
• Other Ligustrum species are invasive
  
• Toxic to animals (horses) and people
  
• Shade-tolerant
  
• Tolerates many soil types
  
• Forms dense stands, excluding other vegetation
  
• Reproduces by seeds and vegetatively by suckering
  
• Seeds dispersed by birds, other frugivorous animals and intentionally by people
  
• Able to resprout from cut stumps

Low Risk Traits:

• Unarmed (no spines, thorns, or burrs)
  
• Browsed by deer (palatable despite reports of toxicity)
  
• Ornamental
  
• Reaches maturity in 3+ years
  
• Herbicides may provide effective control