Family: Poaceae

High Risk Traits:

• Broad climate suitability and elevation range exceeds 2000 m, demonstrating environmental versatility
  
• Naturalized in regions with tropical climates
  
• Widely naturalized
  
• Agricultural and environmental weed
  
• Other Holcus species are invasive
  
• Alternate host of pests and pathogens
  
• Pollen may be allergenic
  
• Increases fuel load in fire prone habitats
  
• Tolerates shade, but prefers full sun
  
• Tolerates many soil types
  
• Forms dense cover
  
• Reproduces primarily be seeds and secondarily by tillering
  
• Hybridizes with Holcus mollis
  
• Seeds dispersed by wind, water, as a crop contaminant, internally and externally by clinging to equipment, clothing, and animals
  
• Prolific seed production (>1000/m2)
  
• Forms a persistent seed bank (5-20 years)
  
• Tolerates mowing and fire

Low Risk Traits:

• Unarmed (no spines, thorns or burrs)
  
• Palatable to browsing and grazing animals (but lower than other grasses)
  
• Primarily outcrossing (mostly self-incompatible)
  
• Herbicides provide effective control