Family: Fabaceae

Bauhinia purpurea, commonly known as purple bauhinia or the butterfly tree, is a small to medium-sized ornamental tree native to Southeast Asia. It’s easily recognized by its showy, magenta-purple orchid-like flowers, distinctive two-lobed leaves, and light, spreading canopy. Purple bauhinia is widely planted in tropical and subtropical regions for shade, landscaping, and its striking floral displays that attract bees and butterflies. In Hawaiʻi, it has been used in gardens, parks, and along streets for its beauty and relatively fast growth.

Despite its popularity, Bauhinia purpurea poses risks in Hawaiʻi’s ecosystems. The tree produces abundant pods that split open and eject seeds, allowing it to spread into nearby disturbed areas and roadsides. Once established, it can grow quickly and compete with other vegetation, potentially altering plant communities and reducing space for native species to thrive. Because of these traits, purple bauhinia is not recommended for planting in Hawaiʻi, especially near natural or unmanaged areas. Choosing non-invasive or native alternatives helps protect Hawaiʻi’s unique landscapes while still providing ornamental value.

High Risk Traits:

• Broad climate suitability (tropical/subtropical)
  
• History of repeated introductions worldwide
  
• Naturalized beyond native range
  
• Documented as environmental weed (invasive in Florida)
  
• Congeneric species are invasive
  
• Shade tolerant
  
• Tolerates wide range of soil conditions (clay, sand, saline)
  
• Nitrogen-fixing capability
  
• Produces viable seeds
  
• Self-compatible (can self-pollinate)
  
• Intentionally dispersed by people (ornamental planting)
  
• Tolerates mutilation/regenerates after damage

Low Risk Traits:

• No spines, thorns, or burrs
  
• Palatable to grazing animals (used as fodder)
  
• Not toxic to humans or animals
  
• Doesn't form dense thickets
  
• No vegetative reproduction
  
• Moderate generative time (2-3 years to maturity)
  
• Limited unintentional dispersal (no attachment mechanisms)
  
• Large seeds, not wind/water dispersed
  
• No persistent seed bank