Common burdock

Common BurdockCommon burdock is a member of the Aster or Sunflower family, Thistletribe. It is an introduced biennial which reproduces by seeds. In thefirst year of growth the plant forms a rosette. The second year theplant is erect. The stem is stout, grooved, rough, has multiplebranches, and grows to 2-6 feet tall.

The leaves are alternate,dark green, smooth above, whitish green, and woolly hairy beneath. Theflowers are purple or white in numerous heads. The head is enclosed in aprickly bur, an involucre, composed of numerous smooth or wooly bractstipped with hooked spines.
Burdock grows along roadsides, ditchbanks, and neglected areas. This plant is a very serious threat to sheepas the burs can significantly damage the quality of the wool. Burdockis very common in central and north central Colorado.

Burdock rosette Burdock rosette
burdock bloom burdock death