Family: Blechnaceae

Blechnum gibbum, commonly known as the dwarf tree fern or silver lady fern, is a small, elegant fern native to Fiji, New Caledonia, and nearby Pacific islands. It forms a compact trunk topped with a symmetrical crown of bright green, finely divided fronds, giving it a miniature “tree” appearance. This species is widely grown as an ornamental for its tidy shape and lush tropical look, and it is popular in landscapes, shaded gardens, and as a container plant—both indoors and outdoors in suitable climates.

At present, Blechnum gibbum is not known to be naturalized in Hawaiʻi, and there is no evidence that it poses an active threat to native ecosystems. However, as with other tree ferns, it possesses traits—such as shade tolerance, slow but steady growth, and potential for spore-based spread—that warrant attention. Although there are no documented impacts in Hawaiʻi, further evaluation is needed to determine whether this species could naturalize or compete with native understory plants in the future.

High Risk Traits:

• Thrives in tropical climates
  
• Other Blechnum species have become invasive
  
• Shade-tolerant
  
• Spores dispersed by wind and possibly water
  
• Planted intentionally by people
  
• Prolific spore production
  
• Limited ecological information makes accurate risk prediction difficult

Low Risk Traits:

• No reports of invasiveness or naturalization
  
• Unarmed (no spines, thorns or burrs)
  
• Non-toxic
  
• Ornamental
  
• Requires acidic to neutral soils
  
• Not reported to spread vegetatively