Ragwort
Cushag (Manx); Stinking Willie
- Known today as
- Jacobaea vulgaris (syn. Senecio jacobaea). A tall, weedy, yellow-flowered daisy of pastures and waste ground.
- Kind
- Plant, in 2 older authorities
- Constituents
- jacobine, senecionine, seneciphylline, and 1 more
- Earliest authority here
- Pliny (AD 23/24–79)
- In other databases
- Plants of the World Online search · GBIF search · Wikidata search
Revised October 1, 2026: An older authority added from a text read in full. Version 1, first published September 27, 2026.
Caution. Toxic to livestock, especially horses; handle with care.
Ragwort: what was it used for?
None in human medicine; long known to graziers as a danger to stock.
Ragwort: what does modern science say?
Ragwort contains pyrrolizidine alkaloids that cause fatal liver disease in grazing animals, especially horses, and is a serious agricultural hazard, though the bitterness of the fresh plant usually keeps animals from choosing it.
Ragwort: is it poisonous?
Yes, in some form or dose. Toxic to livestock, especially horses; handle with care. Its poisoning is pyrrolizidine alkaloids (veno-occlusive disease): Weeks to months of use. Historical description, not medical advice; in a poisoning, call a poison centre.
Pharmacognosy & Toxicology
- Constituents
- jacobine ChEMBLa pyrrolizidine alkaloid
- senecionine ChEMBL
- seneciphylline ChEMBL
- retrorsine ChEMBL
- Mechanism
- The alkaloids are activated in the liver to pyrroles that cross-link DNA and proteins, killing the hepatocytes and blocking the small hepatic veins: a slow, cumulative, irreversible liver damage that kills horses and cattle months after the grazing and caused human epidemics (Jamaica, Afghanistan, South Africa) through contaminated grain and bush teas. The honey of ragwort carries the alkaloids.
- Toxic dose
- No safe dose; the damage accumulates.
- Syndrome
- Pyrrolizidine alkaloids (veno-occlusive disease)
- Standing
- A notifiable weed under the UK Weeds Act 1959; no human use; the alkaloids are restricted in food by the European Union since 2020.
- Stegelmeier, B. L., et al. (1999). “Pyrrolizidine alkaloid plants, metabolism and toxicity.” Journal of Natural Toxins 8. Verified against its record · PMID 10091131
- European Commission (2020). Regulation (EU) 2020/2040 on maximum levels of pyrrolizidine alkaloids in certain foodstuffs. Standard reference work
The abstract of each source, beneath its citation. For Club members. About the Club or sign in.
Constituent names open the compound’s record at PubChem, and “ChEMBL” beside a name opens its record at ChEMBL, the European Bioinformatics Institute’s database of bioactive molecules. Where a mechanism line was checked against ChEMBL (ChEMBL 37, read 1 October 2026), the check is shown with the measured value and its source paper, or says plainly that nothing has been measured. Doses are as the references give them, for description only; this is not medical advice. Each source carries the result of its check against Crossref, PubMed, or the authority’s page: see Verification.
Ragwort: what lore surrounds it?
On the Isle of Man children were taught to apologize to ragwort before pulling it up, or risk the fairies’ displeasure, and it is the Manx national flower, the cushag. In the Scottish Highlands it is “Stinking Willie,” a name tradition ties both to its smell and to William, Duke of Cumberland, whose forces are said to have spread its seed through the Highlands in horse fodder after Culloden in 1746.
Ragwort: what did the older authorities say?
- Pliny
- Erigeron “is called by our people ‘senecio.’” Pliny records the toothache rite in full: “if a person, after tracing around this plant with an implement of iron, takes it up and touches the tooth affected with it three times, taking care to spit each time on the ground, and then replaces it in the same spot, so as to take root again, he will never experience any further pain in that tooth.” The plant grows “upon walls, and the tiled roofs of houses,” and the Greeks named it erigeron “because it is white in spring.” He notes the Greek writers “are by no means agreed as to this plant” and confines himself to Roman uses: the down beaten up with saffron for defluxions of the eyes, and parched with salt for scrofulous sores.
- Culpeper
- Under Venus; it “cleanses, digests, and discusses”: the decoction washes ulcers of the mouth and throat and helps the quinsy and the king’s evil, the juice heals green wounds, and an ointment of the herb boiled in old hog’s suet with mastic and olibanum is for the sciatica; “In Sussex we call it Ragweed.”
Sources
- Plant-Lore, “Ragwort.” Book, seen in reviews
- Pliny the Elder, Natural History 25.106, trans. J. Bostock & H. T. Riley (1855), Perseus Digital Library. Primary text
- Culpeper, N. (1653). The Complete Herbal, “Ragwort.” Project Gutenberg #49513. Primary text
Verification
- Checked
- October 1, 2026
- Passes
- Every sentence read against its sources, in the pass over the remaining 343 entries
- The Standing line checked against the authority it names (EMA, WHO, FDA, CITES, Commission E)
- Every dated or regulatory claim checked by category across the database
- Each quotation from the older authorities checked word for word against the text, read in full
- Sources
- 5 cited: 1 verified against its record, 2 primary text, 1 standard reference work, 1 book, seen in reviews. 1 with the abstract on file.
- Corrections
- None were needed.
What was checked, how, and what was found is set out on the Verification page. A checked source is one whose record was found; it does not make the entry medical advice.
Cite This Entry
Version 1 · first published September 27, 2026 · last revised October 1, 2026
- Chicago
“Ragwort.” In Materia Medica, edited by B. C. P. Statema. Version 1. The Thinking Press, 2026–. Last modified October 1, 2026. https://thethinkingpress.org/materia-medica/ragwort.
- MLA
“Ragwort.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 1 Oct. 2026, thethinkingpress.org/materia-medica/ragwort. Accessed 8 Oct. 2026.
- APA
Ragwort. (2026, October 1). In B. C. P. Statema (Ed.), Materia medica (Version 1). The Thinking Press. Retrieved October 8, 2026, from https://thethinkingpress.org/materia-medica/ragwort
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See Also
Poisoned alike: pyrrolizidine alkaloids (veno-occlusive disease)
Alkanet · Houndstongue · Borage · Comfrey · Butterbur · Coltsfoot · the syndrome, with all of them →
Also in Pliny the Elder
Rocket in Pliny the Elder · Polypody of mercurialis, syrup of in Pliny the Elder · Rosemary rice water in Pliny the Elder · Pilewort in Pliny the Elder · everything Pliny the Elder names →
Also in Nicholas Culpeper
Raisins in Nicholas Culpeper · Periwinkle in Nicholas Culpeper · Red roses in Nicholas Culpeper · Motherwort in Nicholas Culpeper · everything Nicholas Culpeper names →
Drawing on the same sources: Plant-Lore, Culpeper, Stegelmeier
Speedwell · Yarrow · Wild carrot, seed of · The precious stones · the bibliography →
Nearby in the alphabet
Radish (Raphanus sativus (now classed by Kew as Raphanus raphanistrum subsp) · Ramps (the wild leek of the hardwood forests of the Great Lakes and the East) · Quince (Cydonia oblonga) · Quicksilver (and its salts such as calomel and corrosive sublimate) · Red yeast rice (Rice fermented with a red mould) · Purslane (a succulent, creeping herb of warm gardens)
Historical description, not medical advice.