Common Name:
Scotch Thistle
Scientific Name:
Onopordum acanthium L.
Family:
Asteraceae


Photo courtesy of the
British Columbia Ministry of Agriculture, Food and Fisheries

Description: Scotch thistle is a biennial with multiple stems that can grow up to 8 feet tall. The plant has spiny, winged stems and coarse, lobed leaves. Leaves in the basal rosette can be 2 feet long. Globe-shaped flower heads are purple or purple-red with spine-tipped bracts, occurring in clusters of two or three. Scotch thistle is a native of Europe and eastern Asia.

Control: Biennial plants require depletion of nutrient reserves in the root system to reduce second-year growth, prevention of seed production and prevention of dispersal.