Have Burs Will Travel
Cocklebur or Burdock—What's the Difference?
By Celestine Duncan
Common cocklebur (Xanthium strumarium L.) and common burdock (Arctium minus) are members of the sunflower family. Both plants have bur-like seed heads that are easily spread by clinging to human clothing, and fur of domestic animals, wildlife, and livestock. Although the plants share similar habitat and are both widely distributed across the United States and southern Canada, cocklebur tends to flourish in warmer regions than burdock (Figure 1).
Figure 1: Distribution of common cocklebur (left) and common burdock (right) in the United States (EddMapS 2017).
Cocklebur is native to the United States and is primarily a weed of riparian areas, pastures, disturbed areas and cultivated cropland. Burdock is introduced from Eurasia and likely reached North American with early English and French settlers. It was considered ‘widespread’ in Pennsylvania by the mid 1800’s and is now naturalized throughout North America. It is found primarily in riparian sites, pasture margins and natural areas; however, it is not problematic in cultivated land.
Common cocklebur and burdock differ in their life cycle, growth form, flower type and seed heads. The following information compares differences between the two weeds.