# Polypody of mercurialis, syrup of (Polypodium vulgare)

**Polipodio del Mercuriale**

**Known today as.** A syrup of polypody fern root (*Polypodium vulgare*), named in Canale the syrup of polypody “del Mercuriale,” perhaps with annual mercury (*Mercurialis annua*).

Kind: Compound  
Toxic: yes

> **Caution.** 

## What did Canale use it for?

A purge used at the outset and again in the stronger purges for melancholic patients (chs. 2, 4).

## What does modern science say?

Polypody root is a laxative. Annual mercury has long been a laxative and purgative in Spanish folk medicine, though the genus is counted toxic to humans and animals.

## Pharmacognosy and toxicology

- **osladin**: a saponin of the rhizome, responsible for its sweet taste
- **polypodosaponin**: 
- **ecdysteroids**: 

**Mechanism.** The rhizome of the polypody fern, which Culpeper calls “a gallant, though gentle purger of Melancholly”: Dar and colleagues list it as laxative and expectorant, with a fatty oil said to purge and the saponin osladin giving its sweetness. Annual mercury, if that is what the name means, is a laxative of Spanish folk medicine.

**Dose.** Culpeper bids it be bruised and boiled in white wine, more or less according to the strength of the patient, and says it works very safely.

**Standing.** Polypody root is still used in European herbal medicine, for the liver and for indigestion, by Dar and colleagues’ account; its saponin is said to suppress cough.

## What did the older authorities say?

**Pliny.** Among the remedies drawn from poultry, gives a broth of cock or capon boiled with the plant mercurialis, polypodium, or dill (or sea-cabbage, salted tunny, capers, or parsley), the bird boiled in three congii of water down to three semi-sextarii, cooled in the open air, and given “just after an emetic has been administered,” for the liver, kidneys, bladder, indigestion, and asthma.

## Sources

- Pliny the Elder, *Natural History* 29.25, trans. J. Bostock & H. T. Riley (1855), Perseus Digital Library.
- Jizba, J., et al. (1971). “Polypodosaponin, a new type of saponin from *Polypodium vulgare*.” *Chemische Berichte* 104.

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*Polypody of mercurialis, syrup of.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/polypody-of-mercurialis-syrup-of

Historical description, not medical advice.