Family: Fabaceae

The royal poinciana was brought to Hawaiʻi by the great botanist Dr. Hillebrand in 1855. This tree remains a popular ornamental today and is widely cultivated. Rarely found growing wild in its native land of Madagascar, it isn’t listed as endangered due to the widespread cultivation.

The spectacular red flowers bloom from January to October. A grand specimen shade tree, the royal poinciana has a broad, spreading, flat canopy full of feathery leaflets. This mighty tree can damage streets, foundations, and rock walls from its aggressive root system. Nitrogen-fixing tree and drought tolerant, it grows well in dry areas.

The tree can be messy when it drops its leaves in the winter months. The tree litter is allelopathic.

Plant Uses:

• Lei flower
• Nitrogen fixer
• Ornamental
• Shade
• Specimen
• Woodworking

Plant Dangers:

• Allelopathic

High Risk Traits:

• Broad climate suitability: Altitude range 0–2000 m; dry/moist tropics
  
• Widely introduced: Planted throughout tropics and subtropics
  
• Allelopathic: Suppresses understory vegetation
  
• Wide soil tolerance: Grows on alluvium, shale, limestone, and other types
  
• Nitrogen-fixing: Competitive advantage in poor soils
  
• Persistent seed bank: Seeds viable in soil for 2–3 years
  
• Tolerates mutilation: Withstands severe pruning
  
• Reproduces by seed: Produces abundant viable seed

Low Risk Traits:

• Not a significant weed: No evidence of being agricultural, environmental, or garden weed elsewhere
  
• Large seeds: Low seed production per m² (1600–3700 seeds/kg)
  
• Poor dispersal mechanisms: No adaptation for wind, water, animal attachment, or unintentional human dispersal
  
• Self-incompatible: Requires cross-pollination for seed set
  
• Shade-intolerant: Slow growth under shady conditions
  
• Palatable: Leaves and pods edible for livestock
  
• Fire-sensitive: Young plants susceptible to fire
  
• No congeneric weeds: Other Delonix species not problematic