# Yellow dock (Rumex crispus)

*Curled dock; dock*

**Known today as.** *Rumex crispus*. A tall, coarse weed of waste ground with wavy-edged leaves and a tall spike of rust-brown seeds.

Kind: Plant  
Poisoning: The anthranoid purgatives (https://thethinkingpress.org/materia-medica/poisons/anthranoid)

## What was it used for?

The root used as a mild laxative and “blood purifier” in traditional herbalism; the fresh leaf rubbed on the skin as folk first aid.

## What does modern science say?

Its genuine mild laxative action comes from anthraquinones like those of rhubarb and senna. An informal modern test found treated stings eased within minutes against hours for the untreated hand, but the effect has never been confirmed in a controlled trial, and some researchers doubt the leaf does more than the rubbing.

## Pharmacognosy and toxicology

- **nepodin**: a naphthalene
- **emodin and chrysophanol**: anthraquinones, 2–4 per cent of the root
- **tannins**: 
- **oxalates**: in the leaf

**Mechanism.** The root’s anthraquinones are a mild laxative by the colonic route, and its tannins astringe, which gives the old “purges and then binds”; the leaf rubbed on a nettle sting is cooling and alkaline mucilage, not an antidote. The leaf’s oxalate has poisoned in quantity.

**Dose.** The root at 2–4 g is a gentle laxative; the leaf is a food in moderation.

**Standing.** No EMA monograph; in American and British herbal tradition for skin and constipation.

## What lore surrounds it?

“Nettle in, dock out,” the rhyme for rubbing a dock leaf on a nettle sting, appears as early as Chaucer’s *Troilus and Criseyde* in the fourteenth century, one of the oldest folk remedies still practiced in the English-speaking world.

## What did the older authorities say?

**Pliny.** “It is only the lapathum that is better in a wild state than cultivated: in its cultivated state it is the same plant that is known to us as the ‘rumix,’ being the most vigorous by far of all the plants that are grown; so much so, indeed, that it is said that when it has once taken root, it will last for ever, and can never be extirpated from the soil, more particularly if water happens to be near at hand.” Its juices, used in ptisans, impart “a softer and more exquisite flavour,” and “the wild variety is employed for many medicinal purposes.” Elsewhere he notes that of the garden plants “it is lapathum, however, that has the longest root of them all, it attaining the length of three cubits even.”

**Culpeper.** All docks are under Jupiter, and “the yellow Dock-root is best to be taken when either the blood or liver is affected by choler”; the seed stays fluxes, and the roots boiled in vinegar help the itch and scabs; of bloodwort, “as wholesome a pot herb as any,” he complains that women will not put it in the pot “because it makes the pottage black.”

## Sources

- Country Life, “Do dock leaves really cure nettle stings?”
- Pliny the Elder, *Natural History* 19.60; 19.31, trans. J. Bostock & H. T. Riley (1855), Perseus Digital Library.
- Culpeper, N. (1653). *The Complete Herbal*, “Dock.” Project Gutenberg #49513.
- Vasas, A., et al. (2015). “The genus *Rumex*: review of traditional uses, phytochemistry and pharmacology.” *Journal of Ethnopharmacology* 175.

---

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

Historical description, not medical advice.