Family: Asteraceae

High Risk Traits:

• Able to grow in temperate and subtropical climates.
  
• Widely cultivated and naturalized (but no evidence in the Hawaiian Islands to date).
  
• A common weed of other agricultural crops worldwide.
  
• Other Matricaria species are invasive weeds.
  
• May be allelopathic.
  
• Unpalatable to deer, and other browsing and grazing animals (although cows may consume it in infested pastures).
  
• May taint milk if consumed by dairy cows.
  
• May be mildly toxic or cause dermatitis to susceptible people.
  
• Tolerates many soil types.
  
• Reproduces by prolific seed production.
  
• Self-fertile.
  
• Quickly reaches reproductive maturity (< 1 year).
  
• Seeds dispersed by externally on farm equipment, and possible animals, as a crop contaminant, internally by cattle, and through intentional cultivation.
  
• One plant can produce up to 5000 seeds.
  
• Seeds may form a persistent seed bank (up to 11 years).

Low Risk Traits:

• A primarily temperate species that may not thrive in tropical climates, and may be a greater risk at cooler, higher elevations of tropical island ecosystems.
  
• Valued and cultivated as an herbal and medicinal plant.
  
• Unarmed (no spines, thorns, or burrs).
  
• Grows best in high light environments (dense shade may inhibit spread).
  
• Hand pulling can be effective in controlling smaller populations. Mowing may limit seed set in larger infestations.
  
• Herbicides may provide effective control.