Family: Aquifoliaceae

Origin, Description & Uses
Kurogane holly (Ilex rotunda) is an evergreen tree native to East Asia, including Japan, southern China, Korea, and Taiwan. It typically grows as a medium-sized tree with a dense, rounded canopy and attractive, glossy dark green leaves. Small white flowers are followed by bright red to black berries on female plants. It is widely planted as an ornamental in landscapes, parks, and urban settings for its year-round foliage, tolerance of pruning, and ability to provide shade and screening.

Risks & Threats
Although Ilex rotunda is not known to be naturalized in Hawaiʻi, it does possess traits that are cause for concern. Its bird-dispersed seeds, adaptability to a range of environments, and popularity in ornamental plantings increase the potential for escape from cultivation. In similar island and warm-temperate environments, related species in the holly group can spread beyond plantings and compete with native vegetation. Caution is recommended to ensure that it will not negatively impact Hawaiʻi, and continued evaluation is warranted before wider use in the landscape.

High Risk Traits:

• Grows in temperate and tropical climates
  
• Possibly naturalizing in Georgia (confirmation needed)
  
• Listed as a native weed in Japan (but no specific impacts described)
  
• Other Ilex species have become invasive
  
• Possibly unpalatable to animals
  
• Tolerates many soil types
  
• Seeds dispersed by birds and intentionally by people
  
• May form a persistent seed bank
  
• Able to resprout after cutting to ground level

Low Risk Traits:

• Unarmed (no spines, thorns or burrs)
  
• Ornamental
  
• Dioecious trees (and therefore not self-fertile)
  
• Not reported to spread vegetatively
  
• Slow growth rate and long time to maturity