Common burdock is a List C biennial species and belongs to the sunflower family (Asteraceae).
A native to Europe, it is found throughout much of North America. Common burdock invades riparian corridors, irrigation ditches, pastures, and rangeland.
Common burdock has seeds that are covered in small barbs that stick to clothing and fur, which aids in seed dispersal. Each plant can produce up to 15,000 seeds. Its basal leaves are large with undulating edges and it can be mistaken for rhubarb. The upper-side of the leaves can be covered in fine hairs, and the underside can be woolly. Leaves typically wither by the time of flowering. The stem is stout and branched and can grow to 6 feet long. Superficially, the blooms may resemble those of bull thistle.
Common burdock is a secondary host plant for diseases of economically important crops, can reduce the value of sheep wool, and taints milk if heavily grazed.
Control includes removal of seedlings in the fall and spring or treating with herbicide in the spring. Visit us at www.jeffco.us/jcism for more information.
Invasive Plant Atlas
Noxious Weeds of Colorado 14th Addition
Colorado Weed Management Association
Ethan Proud, Archuleta County