Family: Acanthaceae

Barleria lupulina, also known as hophead Philippine violet or hop-headed barleria, is a tropical shrub valued for its cone-shaped flower heads and bright tubular blossoms. Native to Madagascar, it has been widely introduced to warm regions as an ornamental. In Hawaiʻi, it can spread beyond plantings, forming dense clumps in moist or shaded areas. Its ability to root where stems touch the ground, along with fast growth and prolific seed production, helps it establish quickly once it escapes cultivation.

Because it can crowd out other vegetation and spread into natural areas, Barleria lupulina is not recommended for planting in Hawaiʻi. Gardeners seeking similar colors or textures have many safer choices, including native plants that support Hawaiʻi’s ecosystems. If you already grow this species, keep it contained, dispose of cuttings carefully, and monitor for unwanted seedlings. Choosing low-risk alternatives helps prevent invasive ornamentals from impacting Hawaiʻi’s landscapes.

High Risk Traits:

• Thrives in tropical climates
  
• Escaped, and possibly naturalized on Oahu (Hawaiian Islands); widely naturalized elsewhere
  
• An environmental weed in Australia, competing with native vegetation
  
• Other Barleria species are invasive
  
• Armed with spines at leaf axils
  
• Allelopathic
  
• Tolerates many soil types
  
• Forms dense thickets that exclude other vegetation
  
• Reproduces by seeds and vegetatively by stem fragments
  
• Seeds dispersed short distances when capsules rupture, by water, and intentionally planted by people
  
• Also dispersed by dumped garden waste
  
• Tolerates cutting and fire

Low Risk Traits:

• Cultivated in Hawaiian Islands since 1950, but only reported to be escaped on Oahu
  
• Non-toxic
  
• Valued as an ornamental
  
• Herbicides may provide effective control