Family: Asteraceae

High Risk Traits:

• Broad climate suitability and elevation range
  
• Widely naturalized worldwide, including all main Hawaiian Islands except Niihau
  
• A disturbance-adapted weed that impacts several crops
  
• An environmental weed, identified as one of the weed threats to the endangered Hawaiian plant Peucedanum sandwicense
  
• Other Sonchus species are invasive
  
• Potentially allelopathic
  
• May be toxic to lambs and horses
  
• Host of several economically important plant pests and parasites
  
• Tolerates many soil types
  
• Forms dense patches that can exclude other vegetation
  
• Reproduces by seeds
  
• Self-compatible
  
• An annual, able to reach maturity in one growing season
  
• Seeds dispersed by wind, water, by adhering to animals, vehicles, other machinery, as a produce contaminant, and internally by animals
  
• Capable of prolific seed production
  
• Seeds may persist in the soil for one year in the field, and possibly longer

Low Risk Traits:

• Typically invades disturbed or degraded habitats rather than intact native ecosystems
  
• Unarmed (no spines, thorns, or burrs)
  
• Palatable to livestock (in spite of possible toxicity)
  
• Shade intolerant
  
• Certain herbicides may provide effective control