# Hawthorn (Crataegus monogyna)

*May, the May tree*

**Known today as.** *Crataegus monogyna*. The May tree, a thorned hedgerow tree whose white blossom marks the start of May in Britain and Ireland.

Kind: Plant

## What was it used for?

A decoction of the flowers and leaves traditionally taken to steady the blood pressure and support the heart.

## What does modern science say?

Hawthorn extracts have shown modest benefit for mild heart failure in some clinical trials, one of the few folk heart remedies with real supporting evidence.

## Pharmacognosy and toxicology

- **oligomeric procyanidins**: 1–3 per cent
- **vitexin-2 -O-rhamnoside**: a flavone
- **hyperoside**: 
- **crataegolic acid**: 

**Mechanism.** The procyanidins and flavonoids inhibit phosphodiesterase and prolong the cardiac action potential, which strengthens contraction and dilates the coronary vessels; this is one of the few folk heart remedies whose pharmacology has stood up. The standardised extract WS 1442 improved symptoms and exercise tolerance in heart failure in a Cochrane review (2008); the large SPICE trial (2008) found no fall in deaths.

**Dose.** Very safe; no serious toxicity at trial doses of 900 mg of extract a day.

**Standing.** EMA monograph (2016) for the leaf with flower for mild nervous heart complaints and sleep; in Germany a licensed drug for mild heart failure.

## What lore surrounds it?

The only common British plant named for the month it flowers in, hawthorn was central to May Day, its branches cut for May bushes and decked with ribbons and flowers. Solitary “lone bushes” in the Irish landscape were held to be fairy dwellings, and harming one invited supernatural punishment. A strong and widespread taboo forbade bringing the blossom indoors: a British folklore survey of the 1980s found hawthorn named as unlucky more than twice as often as any other plant, a belief with a real chemical root, since the blossom’s trimethylamine is also produced by decaying flesh, giving it a genuine smell of death.

## What did the older authorities say?

**Pliny.** White-thorn appears in Pliny's remedies as an ingredient rather than a subject. Goose blood with olive oil “is kept also as an antidote for all kinds of noxious drugs, made up into lozenges with red earth of Lemnos and juice of white-thorn, five drachmæ of the lozenges being taken in three cyathi of water.” For “ulcerations and chaps of the mouth” he gives “another composition, also, made of veal-suet with stag's marrow and leaves of white-thorn, the whole beaten up together.”

**Culpeper.** A tree of Mars; of the Glastonbury thorn said to flower on Christmas Day he says it “rather shews the superstition of those that observe it,” since the like is found in Romney Marsh and near Nantwich; the seeds beaten to powder and drunk in wine against the stone and the dropsy; the distilled water of the flowers draws out thorns and splinters, “and thus you see the thorn gives a medicine for its own pricking.”

## Sources

- Trees for Life, “Hawthorn tree and mythology.”
- Grieve, M. *A Modern Herbal*, “Hawthorn.” As published on botanical.com.
- Pliny the Elder, *Natural History* 29.33; 28.50, trans. J. Bostock & H. T. Riley (1855), Perseus Digital Library.
- Culpeper, N. (1653). *The Complete Herbal*, “Hawthorn.” Project Gutenberg #49513.
- Pittler, M. H., et al. (2008). “Hawthorn extract for treating chronic heart failure.” *Cochrane Database of Systematic Reviews* 1.
- Holubarsch, C. J. F., et al. (2008). “The efficacy and safety of *Crataegus* extract WS 1442 in patients with heart failure: the SPICE trial.” *European Journal of Heart Failure* 10.
- EMA/HMPC (2016). *European Union herbal monograph on Crataegus spp., folium cum flore* (EMA/HMPC/159075/2014).

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*Hawthorn.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-01. The Thinking Press. https://thethinkingpress.org/materia-medica/hawthorn

Historical description, not medical advice.