Above: Three images of the blessed thistle (Cnicus benedictus). The low stature and unremarkable appearance of this plant belie its medieval reputation as a plague cure and a panacea. The lax stems and spiny, light green leaves are covered with a fine, white down; the spines that subtend the developing flowerhead are a protection against grazing animals. The yellow flowers of this annual thistle appear in July; once the seeds have set, the plant dies. Photographs by Corey Eilhardt.
The humble Cnicus benedictus, a plant of waste ground and stony soil native to the Mediterranean, was a medieval panacea whose reputation survived undiminished into the Renaissance. The sixteenth-century English herbalist John Gerard notes that this wild medicinal plant of southern Europe was “diligently cherished in gardens in these Northern parts.” Gerard also attests that the herb was known everywhere in Europe by the medieval Latin name Carduus benedictus; the common names by which it is known today preserve this designation: blessed or holy thistle in English, benedikten distel in German; chardon bénit or chardon santo in French, cardo benedetto in Italian, cardo bendito in Spanish.
Carduus is the generic name for thistle in classical and medieval Latin, but the modern botanical name for blessed thistle is Cnicus; blessed thistle is the sole member of this genus. It can be difficult to distinguish between the numerous species of thistles and thistle-like plants employed in ancient and medieval medicine. (For an image of an herb designated as blessed thistle in a fifteenth-century Italian manuscript, see the UCLA Index of Medieval Medical Images.)
Even in modern herbalism, blessed thistle is sometimes confused with or substituted for milk thistle, Silybum marianum. Many thistles contain bitter principles thought to be good for the stomach and the liver. The bitter principle contained in blessed thistle (cnicin) has been used to treat stomach, gall bladder, and liver complaints. [For more on milk thistle, see "Another Thistle," (July 26, 2008).]
Cnicus benedictus has sometimes been identified with cnecos, a thistle mentioned by both the Roman natural historian Pliny and the Greek Dioscorides as powerful against the bite of venomous creatures, including scorpions. (Working independently of one another, both of these first-century herbalists record the belief that the pain of a scorpion bite would not be felt by a person holding this thistle.) However, the thistle known as cnecos in antiquity may not have been our Cnicus, but another thistle-like plant, the safflower, Carthamnus tinctoria. The late thirteenth-century herbal of Rufinus remarks on the efficacy of blessed thistle as a cataplasm: a poultice consisting of a warm, moist mass applied to the skin to draw venom. John Gerard upholds blessed thistle’s reputation against dizziness, fevers, and pestilence as well as all poisons and inflammation of the liver when taken internally, and recommends that the green herb be pounded and laid against any “hot” swellings, especially plague sores, the bites of mad dogs, serpents, spiders, and any venomous creatures whatsoever.
The epithet “blessed” is thought to derive from the thistle’s reputation as an aid in a multitude of diseases, and to its great reputation as a plague cure. According to Maude Grieve, blessed thistle appears in virtually all the Renaissance treatises on plague, especially The Poore Man’s Jewell, that is to say, a Treatise of the Pestilence, unto which is annexed a declaration of the Hearbes Carduus Benedictus and Angelica, published by Thomas Brasbridge in 1578.
We had not grown Cnicus benedictus in Bonnefont garden in a good many years, but the enthusiastic interest in thistles expressed by visitors to the blog in the summer of 2008 inspired us to plant it again. The plant has long been naturalized in the United States, and is considered an invasive weed by the U.S.D.A. (We are careful to remove the mature seed capsules before the wind disseminates the thistledown.) When you visit the garden, you will find the blessed thistle growing next to another thistle with a reputation as a plague cure, the carline thistle. [For more on carline thistle, see "The Last of the Thistles" (August 27, 2008).]
Anderson, Frank J., ed. “Herbals through 1500,” The Illustrated Bartsch, Vol. 90. New York: Abaris, 1984.
Gerard, John. The Herbal, or General History of Plants. 1633 edition, revised and enlarged by Thomas Johnson. New York: Dover Press, 1975.
Grieve, Maude. A Modern Herbal. 1931. Reprint: New York: Dover Publications, 1971.
Gunther, Robert T., ed. The Greek Herbal of Dioscorides, translated by John Goodyer 1655. 1934. Reprint: New York: Hafner Publishing, 1968.
Pliny. Natural History, Vol. VI, Books XX–XXIII. Translated by W. H. Jones. 1951. Reprint: Cambridge, MA: Loeb Classical Library, 1969.
Tags: bitter, blessed thistle, Carduus benedictus, carline thistle, cataplasm, cnecos, Cnicus benedictus, Dioscorides, earbes Carduus Benedictus and Angelica, invasive, John Gerard, Maude Grieve, panacea, pestilence, plague, Pliny, Rufinus, Silybum marianum, thistle, Thomas Brasbridge, weed