The Other Side of Yew

By Erin Holden

As an herbalist I’m interested in many aspects of plants – from their use in herbal and conventional medicine, to lore that informs us how those in the past viewed the plant. I knew that Taxol was a cancer drug made from the yew tree, but when a friend mentioned its poisonous aspects, I decided to dig a bit deeper.

Taxol, the well-known cancer treatment, was first isolated and studied in the early 1960s into the late 1970s, and approved as a cancer drug in the early 1990s. Paclitaxel, the common chemical name of Taxol, was initially extracted from the bark of the Pacific yew (Taxus brevifolia). It was quickly realized that extracting enough paclitaxel to meet demand would wipe out this species in short order, so scientists turned to its faster-growing cousin, the European yew (Taxus baccata), as an alternative. A precursor of Taxol is extracted from the leaves of the European yew and then synthesized into the desired drug. Use of the leaves instead of the bark, as well as its fast growth, means the European yew is a more sustainable source of this cancer treatment.

Taxus baccata by Maigheach-gheal in the Church of St. Mary and All Saints in Great BritainThis all sounds well and good, but if we look at the history of yew, we see that it didn’t always have the best reputation – quite the opposite. Whereas Taxol belongs to a chemical group called taxanes, another group, the taxines, is quite deadly. These toxic compounds are found in every part of all Taxus species, in varying amounts, except for the red, fleshy aril. When ingested, taxines act directly on the heart and inhibit its ability to pump properly, causing a drastic drop in blood pressure, arrhythmias, and death. There is no treatment for yew poisoning, and supportive care is not always successful in saving a patient. A brief peek into the medical literature shows that yew has been used in many suicide attempts, both successful and non-fatal. Even as far back as 53 B.C., Julius Caesar recounts how a king of Eburones, Cativolcus, took his own life by drinking the juice of the yew. This deadly aspect of yew, as well as its evergreen nature, likely contributed to yew being associated with death and immortality in both Druidic and Christian cultures.

Church_of_St_Mary_and_St_Christopher,_Panfield_-_churchyard_yew_treesWhile researching, I stumbled upon an interesting “explanation” for how yews became poisonous, written in the 17th century. Since Druids considered yew sacred, many were planted all over England. Their long association with death likely led to cemeteries of new churches being placed near the trees. It was thought that decaying bodies released noxious gases on the south and west sides of a church yard, which then gathered under and were taken up by the yews. Yew roots were thought to “run and suck nourishment” from the dead, whose flesh is “the rankest poison that could be”, and so the trees themselves became poisonous. Because of this association, the church itself was built on the north or north east side of existing trees (https://www.theparisreview.org/blog/2015/10/31/beneath-the-yew-trees-shade/).

I find it fascinating how facts and lore surrounding a plant can mix and have such an impact on various aspects of human activity – from medicine to community planning. And how a life-saving plant can also have a sinister side. Think about it the next time you pass by your ornamental yew. 

Photo Credits: 1) Taxus baccata arils (Frank Vincentz, Wikimedia); 2)Taxus baccata at The Church of St Mary and All Saints in Great Britain (Maigheach-gheal, geograph.org.uk/p/2209844); 3)Line of yew trees in the churchyard of St. Mary and St. Christopher’s Church, Painfield, Essex, England (Image © Acabashi; Creative Commons CC-BY-SA 4.0; Source: Wikimedia Commons)

 Resources:

Grobosch, T. et al. (2013). Eight cases of fatal and non-fatal poisoning with Taxus baccataForensic Science International, vol. 227, issues 1-3, pgs 118-126. https://www.sciencedirect.com/science/article/pii/S0379073812005324?via%3Dihub

Laqueur, T. W. (2015). Beneath the yew tree’s shade. The Paris Review. https://www.theparisreview.org/blog/2015/10/31/beneath-the-yew-trees-shade/; Accessed 2/22/2021. 

Lee, M.R. (1998); The yew tree (Taxus baccata) in mythology and medicine. Proc. R. Coll. Physicians Edinb. vol. 28: 569-575;  https://www.rcpe.ac.uk/sites/default/files/vol28_4.1_12.pdf

National Cancer Institute; Success Story: Taxol® (NSC 125973) https://dtp.cancer.gov/timeline/flash/success_stories/S2_Taxol.htm; Accessed Jan 22, 2021.

Rickard, J. (26 March 2009); Cativolcus, king of the Eburones, d. 53 B.C.  http://www.historyofwar.org/articles/people_cativolcus.html; Accessed 1/22/2021.

Medicinal Disclaimer: It is the policy of The Herb Society of America, Inc. not to advise or recommend herbs for medicinal or health use. This information is intended for educational purposes only and should not be considered as a recommendation or an endorsement of any particular medical or health treatment. Please consult a health care provider before pursuing any herbal treatments.


Erin is the gardener for the National Herb Garden at the U.S. National Arboretum in Washington, D.C. She is a member of the American Herbalists Guild, United Plant Savers, and a member-at-large of the Herb Society of America.

Parsley – Herb of the Month and Herb of the Year

By Maryann Readal

The spotlight is shining on parsley this month. Parsley (Petroselinum crispum) is The Herb Society of America’s Herb of the Month for January and the International Herb Association’s Herb of the Year for 2021. The three most common varieties of parsley are P. crispum or curly-leaf parsley,  P. crispum var. neapolitanum or flat-leaf Italian parsley, and P. crispum var. tuberosum or turnip-root parsley which is grown for its root and is used in soups and stews.

Parsley has an interesting history dating back to Greek and Roman times. To the Greeks, parsley symbolized death and was not used in cooking. However, according to Homer, the Greeks fed parsley to their chariot horses as they thought it gave them strength. The Greeks believed that parsley sprang from the blood of one of their mythical heroes, Archemorus, whose name means “the beginning of bad luck.” From then on parsley had an association with death and misfortune. Victorious athletes in the Nemean games were crowned with wreaths of parsley, symbolizing the contest’s origin as a funeral game dedicated to Archemorus. The Greeks had a saying: “De ‘eis thai selinon” (to need parsley), which meant that a person was near death. They also decorated their tombs with parsley.

parsley italianThe Romans, on the other hand, wore wreaths of parsley to ward off intoxication and used it at meals to mask the smell of garlic. Perhaps this is where the idea of parsley as a garnish originated. It is said that the Romans also covered corpses with parsley to cover the smell of decay. 

The Romans and the Greeks used parsley as a medicine. Pliny the Elder (23-79 CE), in Chapter 20 of his book The Natural History, talks about using a decoction of parsley seeds for  kidney troubles and ulcers in the mouth, and goes on to say that “fish also, if they are sickly in ponds,  are revived by fresh parsley.”  

The Romans brought parsley to England, where colorful folklore arose around the herb, much of it centering around death and ill luck. In Devonshire, it was believed that transplanting parsley would offend the guardians of the parsley bed and that the person doing the transplanting would be punished within the year. In Surrey, it was believed that if someone cut parsley, that person would be crossed in love. In Suffolk, it was thought that parsley should be sown on Good Friday to ensure it coming up double. It was believed that when planting the seeds of parsley, the seed went to the devil nine times and back, with the devil keeping some of the seeds for himself.  This may have been an explanation for the slow germination of parsley seeds. 

parsley root school projectParsley began to be eaten during the Middle Ages.  Charlemagne was said to have grown large quantities of parsley in his gardens for this purpose. Early immigrants brought parsley to the Americas where it was used as a culinary herb.

The association of parsley with death and misfortune played out again in 1937 with the execution of Haitian immigrants in the Dominican Republic. An immigrant’s safety depended on if they could pronounce the word “parsley” correctly. This was called the Parsley Massacre and you can read about this tragic piece of history connected with parsley at https://www.ibtimes.com/parsley-massacre-genocide-still-haunts-haiti-dominican-relations-846773.

parsley pestoParsley is a versatile herb in the kitchen. It adds brightness when sprinkled over any finished dish, and is good in salad dressings, soups and stews. It is one of the ingredients in fines herbes, the French persillade, South American chimichurri, and Mexican salsa verde. The Japanese deep fry parsley in tempura batter, and the Swiss serve deep fried parsley with their fondue. And of course, it is used in pesto. It truly is a universal herb.  Herbalist Madalene Hill, former President of The Herb Society of America, in her book Southern Herb Growing, says that her green butter recipe “should accompany most steaks and that its use will probably relegate the steak sauce and ketchup bottle to the back of the refrigerator where they belong.”  Her recipe is simply one stick of softened butter combined with two cups of finely chopped parsley and one tablespoon of lemon juice.

Parsley is a biennial herb and is easy to grow in moist soil in sun or part shade. It is a good companion plant in the garden, warding off asparagus beetles.  Tomatoes, peas, carrots, peppers and corn will also benefit by having parsley nearby.  The flowers attract bees and hoverflies which eat aphids and thrips. It is also said to improve the scent of roses and keeps them healthier. I like to use parsley as a border plant in my garden, which the Greek and Medieval gardeners were also fond of doing. A benefit of including parsley in your garden is that it is a host plant for the swallowtail butterfly, which will frequently lay eggs on the plant.

Parsley swallowtailWithout a doubt, parsley does have medicinal benefits. It is high in vitamins A, C, and K, and contains antioxidants. The leaf, seed, and root are used in medicine. People have used it to treat bladder infections, kidney stones, gastrointestinal disorders, and high blood pressure. Some apply parsley to the skin to lighten dark patches and bruises. It is also used for insect bites.  Pregnant women are advised not to take parsley in medicinal amounts, as it increases menstrual flow and has been used to cause abortion.

For more information on parsley, go to The Herb Society’s Herb of the Month web page and the Essential Facts for Parsley.

Photo Credits: 1) Curly leaf parsley (Amanda Slater); 2) Italian parsley (Maryann Readal); 3) Parsley root (schoolphotoproject.com); 4) Parsley pesto (Wikimedia Commons); 5) Swallowtail caterpillar (Wikimedia Commons) 

References

Fowler, Marie. Herbs in Greek mythology. The Herbarist. 2010. 

Gardening Know How. Information about parsley. https://www.gardeningknowhow.com/edible/herbs/parsley  Accessed 12/13/20.

Ghosh, Palash. Parsley Massacre:  The genocide that still haunts Haiti-Dominican relations. International Business Times. https://www.ibtimes.com/parsley-massacre-genocide-still-haunts-haiti-dominican-relations-846773  Accessed 12/21/20.

The Herb Society of America. Essential facts for parsley. https://herbsocietyorg.presencehost.net/file_download/inline/140a12b8-0fe0-4a52-ac2c-2b61ea6e786a Accessed 12/22/20.

Hill, Madalene and Barclay, Gwen. Southern Herb Growing. Fredericksburg, TX., Shearer. 1997.

History of parsley-Proverbs & folklore.  http://www.ourherbgarden.com/herb-history/parsley.html Accessed 12/15/20.

Pliny the Elder. Natural History.  Internet Archive. http://www.attalus.org/info/pliny_hn.html Accessed 12/21/20.

WebMD. Parsley. https://www.webmd.com/vitamins/ai/ingredientmono-792/parsley Accessed 12/22//20.

Medicinal Disclaimer: It is the policy of The Herb Society of America, Inc. not to advise or recommend herbs for medicinal or health use. This information is intended for educational purposes only and should not be considered as a recommendation or an endorsement of any particular medical or health treatment. Please consult a health care provider before pursuing any herbal treatments.


Maryann is the Secretary of The Herb Society of America and a Master Gardener. She is a member of The Society’s Texas Thyme Unit in Huntsville, TX. She gardens among the pines in the Piney Woods of East Texas.