Family: Fabaceae

Biancaea decapetala (syn. Caesalpinia decapetala), commonly known as cat’s claw, is a thorny, sprawling vine native to tropical Asia. Introduced to Hawaiʻi in the early 1900s, it was originally planted as a living fence for ranches because it forms dense, nearly impenetrable hedges. The plant has long, arching stems lined with sharp hooked spines, bright yellow flower clusters, and flat seed pods. Today, it is naturalized along roadsides, abandoned house sites, and other disturbed areas from sea level to about 250 meters on Niʻihau, Kauaʻi, Oʻahu, Lana’i , Molokai, Maui, and Hawaiʻi Island.

Cat’s claw is considered a high-risk species in Hawaiʻi due to its aggressive growth and ability to overtake surrounding vegetation. Its thorny vines climb, smother, and shade out native plants, forming thick, tangled masses that are extremely difficult to clear once established. The plant spreads readily in disturbed areas, creating barriers for wildlife movement and human access. Because of these invasive traits and its capacity to harm native ecosystems, Biancaea decapetala is a significant ecological threat in Hawaiʻi.

High Risk Traits:

• Wide climate suitability – tropical/subtropical, up to 1700 m
  
• Naturalized globally – invasive in Hawaii, South Africa, islands
  
• Agricultural and environmental weed – forms thickets, invades forests
  
• Spiny, climbing growth – up to 10 m, unpalatable to livestock
  
• Water-dispersed seeds – spreads along rivers
  
• Hard to control – resprouts after cutting, herbicide-resistant
  
• Fire risk – dry thickets may increase fire hazard

Low Risk Traits:

• No shade tolerance – requires full sun
  
• No vegetative reproduction – does not spread by fragmentation
  
• Seeds not wind-dispersed – no fluff or wings
  
• Not allelopathic or parasitic
  
• No reported toxicity to humans (though plant is considered poisonous)
  
• Low prolific seed production – seeds are medium to large
  
• No persistent seed bank – germinates in 40–50 days