# Moonwort (Botrychium lunaria)

**Lunaria**

**Known today as.** The small fern *Botrychium lunaria*.

Kind: Plant

## What was it used for?

A wound herb, binding and drying.

## What does modern science say?

No established effect.

## Pharmacognosy and toxicology

- **flavonoids**: 
- **tannins**: 

**Mechanism.** *Botrychium lunaria*, a small fern: a mild astringent with no distinctive chemistry, whose fame is for unshoeing horses that trod on it and opening locks, not for medicine.

**Dose.** No toxicity recorded.

**Standing.** No monograph.

## What lore surrounds it?

Said to open locks and to draw the shoes from horses that trod on it; Culpeper records the belief.

The belief that moonwort could draw the shoes from horses that trod on it was taken seriously enough to explain real losses: English writers of the sixteenth and seventeenth centuries tell of the Earl of Essex’s cavalry losing some thirty horseshoes crossing moonwort-covered ground in Devonshire, and witches were said to prize the plant because it could pass iron locks to open stable and house doors. Alchemists took moonwort as the emblem of the “white work,” the albedo stage of the Great Work, for what they read as its silvery, celestial vitality.

## What did the older authorities say?

**Culpeper.** The Moon owns it: cold and drying more than adder’s tongue, boiled in red wine it stays fluxes and bleeding, and it goes into the oils and balsams for green wounds; “Moonwort is an herb which (they say) will open locks, and unshoe such horses as tread upon it,” and he reports thirty horseshoes found pulled from the Earl of Essex’s horses on White Down near Tiverton, “no reason known.”

## Sources

- Culpeper, N. (1652). *The English Physitian*.
- Occult World, on moonwort.
- Culpeper, N. (1653). *The Complete Herbal*, “Moonwort.” Project Gutenberg #49513.
- Thiselton-Dyer, T. F. (1889). *The Folk-lore of Plants*.

---

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

Historical description, not medical advice.