Family: Cyatheaceae

Cyathea arborea (Puerto Rican tree fern, West Indian tree fern) is a tree fern native to the Caribbean. It is used as an ornamental plant due to its attractive foliage and can be used medicinally to treat skin conditions. There are no reports of invasiveness or naturalization, but there is no evidence of widespread introduction outside its native range. This plant is capable of rapidly colonizing hillsides and cleared areas, and forms dense cover in its native range. It also thrives in tropical climates and can grow in areas above 1000m which would be problematic in more high elevation parts of the islands. Other Cyathea species are invasive, including the Australian tree fern, Cyathea cooperi. The Australia tree fern is fast growing and aggressively outcompetes native plants in the forest understory, including native ferns. This fern may have a similar fate if introduced in Hawaiʻi.

High Risk Traits:

• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Thrives in tropical climates
  
• A fast-growing, pioneer species, capable of rapidly colonizing landslides and cleared areas
  
• Other Cyathea species are invasive
  
• Forms dense cover within native range
  
• Reproduces by millions of wind-dispersed spores
  
• Hybridizes with other species
  
• Self-fertile gametophytes
  
• Reaches maturity in 2 years
  
• Spores dispersed by wind and water, and intentionally cultivated

Low Risk Traits:

• No reports of invasiveness or naturalization, but no evidence of widespread introduction outside native range
  
• Unarmed (no spines, thorns, or burrs)
  
• Non-toxic
  
• Not reported to spread vegetatively
  
• Chemical and mechanical control of other invasive Cyathea species may be effective if needed to control C. arborea