The most notable feature of Burdocks are their fruits (burrs), which are covered in hooked tips which attach readily to clothes or fur, thus aiding dispersal of the seeds. The plant itself is stout and leafy with branched stems, with globular flower-heads containing purple florets surrounded by many greenish bracts with the hooked tips.

There are several similar-looking species of burdock. The most common is Lesser Burdock (Arctium minus), with green bracts, purple or pink florets which are longer than the bracts, and solid leaf stalks. This has several sub-species, for example Arctium pubens, where the florets are the same length as the bracts. Wood Burdock (Arctium nemorosum) is similar, with purplish-green bracts. The less common Greater Burdock (Arctium lappa) is larger and has solid leaf stems.