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Report an Invasive Species

Hoary Alyssum

Hoary Alyssum

Hoary Alyssum

(Berteroa incana)

Priority: -  Contain

Tags: Terrestrial | Toxic

Identification and Reproduction


  • Annual to short-lived perennial, up to 80 cm tall. 
  • Grows from a taproot
  • Stems are covered in hairs and branch from the base. 
  • Leaves are greenish-grey, slender with round tips and arranged alternately. Leaves will decrease in size moving closer to the stem tip. 
  • Can over-winter as a rosette, then emerge again in spring
  • Flowers are found in small white clusters near the stem tips. They are composed of 4 small white petals that are each notched. 
  • Seedpods are oval-shaped, have 5-7 black seeds 


Seeds spread by people, equipment, and wildlife.

Habitat & Ecology

  • Establishes in sandy, gravelly soils, and pastures. 
  • Long seed production season.


  • Invades forage and rangeland.
  • Toxic, harmful to horses, which can be very problematic.


Mechanical/Manual Control:

  • When infestations are small hand pulling is effective. Note that entire root crown must be removed. 
  • Burning of mature plants has proven to destroy seeds. 
  • Avoiding mowing mature plants as roots will persist and regrow. 


Download A Guide to Weeds in British Columbia for Hoary Alyssum here.

Header photo (Molekuel). 

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