Family: Costaceae

High Risk Traits:

• Elevation range exceeds 1000 m, demonstrating environmental versatility
  
• Thrives in tropical climates
  
• Naturalized on Oahu and Kauai, Hawaiian Islands, and St. Lucia, Caribbean
  
• Other Costus species have naturalized and may be invasive
  
• Shade-tolerant
  
• Tolerates many soil types
  
• Able to form dense thickets that may exclude other vegetation
  
• Seeds, if produced, dispersed by birds and intentionally by people
  
• Able to hybridize with other Costus species
  
• Self-compatible
  
• Able to spread vegetatively by rhizomes

Low Risk Traits:

• Unarmed (no spines, thorns or burrs)
  
• Non-toxic
  
• Ornamental value
  
• Hummingbird-pollinated in native range (may limit seed set where hummingbirds are absent)
  
• Limited seed production may minimize longer distance dispersal