Family: Asteraceae

High Risk Traits:

• Naturalized outside native range (Hawaii, Pacific, Australia)
  
• Naturalized on Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, and Maui; potentially naturalizing on Kahoʻolawe and Hawaiʻi Island.
  
• Listed among "100 of the World's Worst" invaders
  
• Forms dense mats, smothers native vegetation
  
• Environmental weed in Florida, South Africa, Australia
  
• Toxic to grazing animals (causes abortions)
  
• Shade-tolerant
  
• Grows in wide range of soils (clay, sand, loam)
  
• Reproduces vegetatively (stems root at nodes; fragments regrow)
  
• Dispersed unintentionally (garden waste, trafficked areas)
  
• Dispersed intentionally (ornamental planting)
  
• Wind-dispersed seeds (achenes with pappus)
  
• Tolerates trimming and frost damage (recovers quickly)
  
• No effective natural enemies in invaded areas

Low Risk Traits:

• No spines, thorns, or burrs
  
• Not allelopathic, parasitic, or a pest/pathogen host
  
• Not toxic to humans nor allergenic
  
• Unlikely to create fire hazard
  
• Low seed production (few mature achenes)
  
• No persistent seed bank evidence
  
• No animal-mediated dispersal (birds, mammals, external attachment)
  
• Well controlled by herbicides (glyphosate, metsulfuron, Garlon 4)