Coastal Invasive Species Committee


Hoary Alyssum

Berteroa incana






Family: Brassicaceae (Mustard)

Other Common Names: False hoary madwort, hoary berteroa

Origin: East Central Europe/Western Asia

Habitat:  Dry/gravely soils at low/mid elevations.  Found along roadside ditches and disturbed or heavily-grazed pastures.

Distribution:  South-central & southeastern BC

Legal Status:  Invasive Plant Regulation (Forest and Range Practices Act), Noxious Weed (Weed Control Act).


-Animal:  TOXIC TO HORSES!  Consumption may cause fever, limb edema and laminitis.  

-Ecological:  Unknown.

Description: Hoary Alyssum is an annual to short-lived perennial reaching a height of just over 2 ft.  The entire plant is covered with star-shaped hairs and has four white petal clusters at the stem tips.  Has flattened oval seedpods that are between 5 and 8 mm long and are generally held close to the stem.  

Management:  Small infestations can generally be controlled by repeated hand-pulling and hoeing if performed before the seed has set.  Mowing will reduce seed reproduction, but be aware that plants left un-cut below the mower blade will regenerate.  There are no known biocontrol agents available for treating Hoary Alyssum.  2, 4-D, Glyphosate, Dicumba, and Metsulfuron are all effective herbicides.