Family: Brassicaceae

Brassica napus, commonly known as rapeseed or canola, is a widely cultivated annual or biennial plant in the mustard family (Brassicaceae). It is not a naturally occurring wild species but rather originated centuries ago in Europe from a hybridization between turnip (Brassica rapa) and a leafy kale (Brassica oleracea). Modern breeding in the 1970s developed “canola” varieties with low levels of naturally occurring toxic compounds. The plant is characterized by bright yellow flowers and produces seeds that are crushed for vegetable oil, used globally for cooking, biofuels, and industrial lubricants. Its young leaves are also edible, and certain types are grown as livestock fodder.

Risks and Threats: While a vital agricultural crop, Brassica napus poses several ecological risks, primarily as an agricultural weed. Its seeds can persist in soil for many years, leading to persistent “volunteer” plants that compete with subsequent crops. It readily escapes cultivation, naturalizing along roadsides and in disturbed areas in temperate regions worldwide. The plant can hybridize with wild mustard relatives, potentially spreading cultivated traits into wild populations. In some cases, it has developed resistance to multiple herbicides, making control difficult. Although it is not a major invader of intact native ecosystems, its ability to form long-term seed banks and its history of escape mean it should be planted and managed with care to prevent unwanted spread into agricultural and natural areas.

High Risk Traits:

• Naturalized in temperate regions worldwide
  
• Volunteer populations act as agricultural weeds
  
• Toxic to livestock (goitrogenic compounds)
  
• Host to many pests and pathogens
  
• Can cause allergies in humans
  
• Produces abundant viable seeds
  
• Hybridizes with wild relatives
  
• Self-pollinating
  
• Annual/biennial life cycle
  
• Seeds spread by vehicles, livestock, and human activity
  
• Seeds survive digestion by animals
  
• Persistent soil seed bank (5–10+ years)
  
• Tolerates wide climatic and soil pH ranges
  
• Some forms have storage organs (geophytes)

Low Risk Traits:

• Not well suited to tropical climates
  
• Requires full sun (not shade tolerant)
  
• Lacks spines, thorns, or burrs
  
• Palatable to grazing animals
  
• No vegetative reproduction
  
• Minor impact as an environmental weed