Family: Rosaceae

Rubus argutus (prickly Florida blackberry) is a sprawling, thorny shrub native to the southeastern United States. It produces arching canes armed with sharp prickles and forms dense thickets that can outcompete native vegetation. The plant is easily recognized by its white, five-petaled flowers and clusters of juicy black fruits that are readily spread by birds and other animals. Thriving in a wide range of environments—from disturbed areas and pastures to forest edges—this blackberry quickly colonizes open ground and regenerates vigorously from roots and stems.

In Hawaiʻi, prickly Florida blackberry is naturalized on Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi Island. It is considered an invasive weed in many parts of the world because of its aggressive growth and ability to form impenetrable thickets that hinder native plant regeneration and land management. The plant’s sharp prickles make it difficult to control manually, and its bird-dispersed seeds allow it to spread over long distances. Management requires persistence and a combination of mechanical removal and herbicide treatment to prevent regrowth.

High Risk Traits:

• Naturalized outside native range (e.g., Hawaii, Chile, New Zealand)
  
• Forms dense, impenetrable thickets
  
• Environmental weed that threatens native species
  
• Spines/thorns present on stems and leaves
  
• Tolerant of shade
  
• Reproduces by vegetative fragmentation (root sprouts)
  
• Bird-dispersed seeds
  
• Persistent seed bank (>3 years)
  
• Tolerates and benefits from fire, mowing, and cultivation
  
• Hybridizes naturally with other Rubus species
  
• Tolerant of a wide range of soil types

Low Risk Traits:

• Not allelopathic
  
• Not parasitic
  
• Not toxic to humans or animals
  
• Controllable with herbicides