Teasel is readily recognized by its prickly leaves and stem, along with its pinkish or purplish flowers that form on a large head. In centuries past, dried teasel heads were used in the process of fulling cloth, to raise the nap on fabrics. In fact, according to Brigitte Mars, "the common name teasel derives from the Old English tcesan, "to tease," in reference to the use of the tops in carding wool." In natural medicine, the dried roots are used for a variety of purposes.

Source: Mountain Rose Herbs