Family: Fabaceae

Neltuma juliflora (thorny kiawe), previously known as Prosopis juliflora, is a hardy, drought-tolerant tree native to Central and South America. It was introduced to many tropical and subtropical regions for shade, firewood, and erosion control. The tree is recognizable by its long, paired thorns, small compound leaves, and twisted, tan seed pods that are often eaten and spread by livestock. Thorny kiawe thrives in dry, open areas and can grow into dense, impenetrable thickets that outcompete native vegetation.

In Hawai‘i, Neltuma juliflora is naturalized on Kaua‘i, O‘ahu, and Lana‘i. It has spread primarily in dry coastal and leeward regions, where it forms extensive stands similar to those of its close relative, Neltuma pallida (kiawe). Because of its aggressive growth, thorny thickets, and ability to alter soil chemistry, N. juliflora can negatively affect native ecosystems and rangelands. Its deep roots make it difficult to remove once established, and its sharp thorns can injure animals and humans, complicating land management and restoration efforts.

High Risk Traits:

• Invasive and naturalized globally
  
• Forms dense, impenetrable thickets
  
• Competitively displaces native flora
  
• Toxic to livestock
  
• Allelopathic
  
• Produces spines/thorns
  
• Causes pollen allergies
  
• Host for pests
  
• Hybridizes naturally
  
• Animal and water-dispersed seeds
  
• Persistent seed bank
  
• Fire-tolerant

Low Risk Traits:

• Shade-intolerant
  
• Not self-compatible
  
• No vegetative spread
  
• Not wind-dispersed
  
• Controllable with herbicides
  
• Limited to tropical/subtropical arid climates