Above, from left to right: The seed head of the cultivated form of teasel (Dipsacus sativus) in a bed devoted to plants used in medieval arts and crafts (2006); detail of the seed head of the teasel growing in the same bed this year; detail of the seed head of common teasel, or fuller’s teasel (D. fullonum), now in the medicinal bed.
Visitors to Bonnefont Garden are often surprised to find plants that they recognize as common weeds being carefully cultivated in the beds here. One ubiquitous weed found growing in waste places throughout this country is the common or wild teasel, Dipsacus fullonum, a plant which had various medicinal applications in the European Middle Ages. A distinct but closely related form of teasel, D. sativus, was also introduced here in colonial times, and was cultivated for use in the woolen trade. Both forms have naturalized in the United States (see the U.S.D.A. website), although the wild or common teasel, D. fullonum, is much more widespread than the cultivated variety. There is considerable confusion between the two, and sometimes seed sold as the cultivated form turns out to be the common variety.
Teasel is so called because of the use of the spiny seed heads to tease out woolen fibers before they were spun, a process known as carding, and in raising the nap of finished woolen cloth. While the conical heads of wild or common teasel (Dipsacus sylvestris) may once have been employed in wool carding (some authorities question this) and are sometimes used on a small scale by hand-spinners, they are of no use in raising nap, as the spines are too straight and weak to be effective. The curved cylindrical seed heads of the cultivated form were and are considered to be superior to any other instrument for that purpose. The hooked spines of this form “give” when they are drawn over the cloth, smoothing it rather than snagging it. In the Middle Ages, teasel heads were fitted into wooden frames. In the nineteenth century, the frames might be placed on rotating drums over which the cloth was passed. Although teasel heads began to be replaced with steel brushes in English woolen mills in Victorian times, the very finest finish, especially that of the baize used for high-quality billiard tables, is still produced with teasel.
At one time, D. sativus was considered to be a subspecies of D. fullonum, but the two are now considered to be distinct. The botanical names are somewhat misleading, as the common or wild variety is now known as Dipsacus fullonum—the teasel of the “fullers,” or cloth makers—while the specialized, historically important form used in the wool trade since the Middle Ages is known simply as Dipsacus sativus. ‘Sativus’ is the botanical epithet given to a plant known in a cultivated form that may no longer have an independent existence as a wild species. D. sativus may have been selectively bred for its useful qualities in early times.
We grow both teasels here at The Cloisters, although the common teasel is given a place in our medicinal collection and the cultivated form is grown in the bed devoted to plants used in medieval arts and crafts. This year, the plants that matured from seed sown as D. sativus in the spring of 2008 proved to be the wrong kind and we will need to obtain seeds from a reliable source for planting next spring.
More to come on the medieval medicinal uses of the wild teasel . . .
Griffiths, Mark. The New Royal Horticultural Society Index of Garden Plants. Portland, OR: Timber Press, 1992.
Mabey, Richard. Flora Brittanica. London: Chatto & Windus, 1996.
Ryder, Michael. “Fascinating Fullonum,” Circea: The Journal of the Association for Environmental Archaeology, 1993.