Family: Dryopteridaceae

Dryopteris erythrosora (autumn fern) is an herbaceous, perennial fern growing from short, creeping rhizomes. It is native to subtropical broad-leaved evergreen forests of China and Japan and is widely planted in North America as an ornamental fern, frequently in large commercial landscape plantings. It is now reported as naturalized in several locations in the southeastern United States but is currently only known from cultivation in the Hawaiian Islands. Its ability to spread by wind-dispersed spores and rhizomes suggests it could escape and potentially impact native ecosystems in the islands.

High Risk Traits:

• Broad climate suitability
  
• Naturalized in the Southeastern United States (but no evidence from the Hawaiian Islands to date)
  
• A potential disturbance and environmental weed
  
• Other species may be invasive
  
• Unpalatable to deer and rabbits
  
• Shade tolerant (and may be able to invade understory of native ecosystems)
  
• Forms dense cover (and may exclude other vegetation)
  
• Reproduces by spores and vegetatively by rhizomes
  
• Apogamous (fertilization is bypassed, allowing for rapid reproduction)
  
• Spores dispersed by wind, water, and possibly other vectors
  
• Ferns also spread through intentional cultivation
  
• Prolific spore production
  
• Spores may remain viable for >1 year

Low Risk Traits:

• Unarmed (no spines, thorns, or burrs)
  
• Non-toxic
  
• Prefers shaded, moist habitats. May not thrive in hot, dry, and sunny habitats.