Photo Credit: Nicole Kimmel, Alberta Agriculture & Forestry
Hoary alyssum is native to Eurasia and was most likely introduced to North America in the late 1800s as a seed contaminant.
It is invasive in open grassland and can become a problem in rangelands. It is toxic to horses.
Hoary alyssum's flowers are arranged in round clusters, are small, white, and have four deeply notched petals.
The sessile leaves are grey-green in colour, covered with star-shaped hairs, and are alternately arranged along the stem.
The fruits are flat, elliptical and covered in hairs.
The stem can reach 30-90 cm tall and is also covered with star-shaped hairs.