Family: Phyllanthaceae

Origin, Description & Uses
Phyllanthus reticulatus, commonly known as potato bush or roast potato plant, is a thorny shrub or small tree native to tropical and subtropical regions of Asia through northern Australia. It typically grows as a dense, sprawling plant with slender branches, oval leaves, and small dark purple to black berries. The plant is sometimes cultivated as a hedge, barrier plant, or ornamental because of its fast growth and dense form. In parts of its native range, it has also been used in traditional medicine and as a minor source of fuelwood or browse. This species is naturalized in Hawaiʻi, where it can establish readily in disturbed areas and lowland habitats.

Risks & Threats
Although sometimes planted for practical uses, Phyllanthus reticulatus possesses traits that are cause for concern in Hawaiʻi and other tropical island environments. It produces abundant seeds that may be spread by birds and other animals, allowing it to invade forests, roadsides, riparian areas, and unmanaged lands. Its dense, thorny growth can form impenetrable thickets that crowd out native vegetation, reduce biodiversity, and hinder access for land management and restoration efforts. Because this species is naturalized in Hawaiʻi and has the potential to detrimentally impact tropical island ecosystems, Plant Pono recommends choosing a low risk or native alternative whenever suitable alternatives are available.

High Risk Traits:

• Broad climate suitability (tropical to temperate)
  
• Naturalized outside native range (Hawaii, Japan)
  
• Agricultural weed (invasive in cultivated land)
  
• Congeneric weeds exist (P. tenellus, P. urinaria)
  
• Climbing/smothering growth habit
  
• Shade tolerant
  
• Produces viable seed
  
• Hybridizes naturally
  
• Bird-dispersed (fleshy berries)
  
• Seeds survive gut passage
  
• Intentional human dispersal (ornamental)
  
• Flowers in 2 years (short generation time)

Low Risk Traits:

• No spines, thorns, or burrs
  
• No allelopathic evidence
  
• Palatable to grazing animals (goats, game, stock)
  
• No evidence of toxicity to animals
  
• No evidence of environmental weed status
  
• No vegetative fragmentation (cuttings fail)
  
• Not wind-dispersed
  
• Not a produce contaminant
  
• No persistent seed bank (unknown, but no evidence of >1 yr)