Family: Hydrocharitaceae

High Risk Traits:

• Broad climate suitability
  
• Naturalized in North America from Ottawa, Montreal, Lake Ontario, Quebec City, central and southwestern parts of southern Ontario, and northern New York, Vermont and eastern Michigan
  
• A weed of aquatic habitats that can impact fisheries, recreation, and biodiversity
  
• Other Hydrocharis species have become weeds
  
• Smother water surfaces
  
• Forms dense mats
  
• Reproduces by weeds and vegetatively
  
• Can reproduce in one growing season
  
• Seeds and vegetative parts dispersed by water, intentionally by people, attached to boats, waterbirds, and possibly internally by birds
  
• Vegetative propagules (turions) may persist over one growing season

Low Risk Traits:

• Primarily in temperate climates. May only be invasive at higher elevations of tropical climates
  
• Unarmed (no spines, thorns or burrs)
  
• Palatable to aquatic animals
  
• Dioecious or self-incompatible
  
• Herbicides may provide effective control