A biennial that produces a rosette of very large leaves in the first year and a branched stem with many burs during the second year. Found across the upper half of the United States and is most commonly found as a weed of pastures, hay fields, and fence rows. Young leaves are also egg-shaped, except at the truncated base. The undersides of these leaves are loosely hairy and light green. Stem leaves are much smaller, alternate, and egg-shaped.
Flowers dry to a bur, and the hooked bracts are often confused with a thistle.
Produced during the second year of growth. Stems are erect, branched, hollow, hairy, and ridged. Stems may reach 5 ft in height. After senescence, the remaining burs on the stems of common burdock may resemble a thistle. However, the dried flowers of thistle plants do not have hooked bracts like common burdock.