A very large leaved plant, often described as `looks like rhubarb.` Due to similarities in the common names (not the plants), it is sometimes confused with common cocklebur. Burdock burs are relatively soft and can be torn apart while cockleburs are hard and remain intact. The petioles are hollow which is important in distinguishing this species from Arctium lappa (great burdock) which is generally larger in most features. Also similar to Arctium tomentosa which has many cobwebby hairs intermixed with the bristles of the bur.