Family: Anacardiaceae

Christmas berry tree is an invasive tree that is native to Brazil, Paraguay, and Argentina. 

In Florida, where it is a noxious weed, it was used ornamentally as a Holly substitute (another invasive species in Hawaii) due to similar red fruits. In fact, it was once called Florida Holly. In Hawaii, some refer to it as a Christmas berry tree, others call it Brazilian pepper tree. It was imported to Hawaii in 1911 as an ornamental.

From 1927 to 1935, Christmas berry tree was widely planted as a forestry tree. 1400 trees were planted on Hawaii Island, Maui, Oahu, and Kauai. Today it is invasive on all the main Hawaiian Islands. 

Shade tolerant and bird-dispersed seeds means it can invade intact native forests. This species is directly threatening the existence of the endangered plant Abutilon sandwicense. It also dominates pasture lands rendering them useless. 

Christmas berry tree is drought tolerant, fire-adapted, and can withstand flooding. The allelopathic tree puts out chemicals in the soil that prevent the growth of other species. The short trunk and tangle of horizontal branches an impenetrable thicket. Monotypic stands are common. 

Description and Dispersal:

• Short stout trunk with numerous horizontal branches.
  
• Compound leaves are alternatively arranged, sometimes red, and have finely toothed leaflets.
  
• White flowers grow in clusters.
  
• Clusters of shiny fruits are green, turning to red as they ripen.

High Risk Traits:

• Widespread naturalization beyond native range (tropics/subtropics globally).
  
• Naturalized across the Hawaiian Islands, including Kuaihelani (Midway Atoll), Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Maui, and Hawaiʻi.
  
• Environmental weed that forms dense thickets, displacing native vegetation.
  
• Agricultural weed impacting grazing lands.
  
• Congeneric weed
  
• Allelopathic – produces chemicals that suppress other plants.
  
• Toxic – unripe fruits fatal to horses; causes skin/respiratory reactions in humans.
  
• Shade tolerant – can survive under canopies until gaps appear.
  
• Broad soil tolerance (fine to coarse textures).
  
• Vegetative reproduction – resprouts from trunk and roots.
  
• Bird-dispersed seeds – widely spread via gut passage.
  
• Early reproduction – can flower within 3 years.
  
• Resprouts after fire (~20% of seedlings).
  
• Prolific seed production (~80,600 seeds/kg)

Low Risk Traits:

• Dioecious (male and female on separate plants)
  
• No spines, thorns, or burrs.
  
• Palatable to goats (foliage browsed without ill effects).
  
• Not a fire hazard – recommended as fire-resistant barrier.
  
• Short seed bank longevity – viability drops to near zero within 5 months.