# Rest-harrow (Ononis spinosa)

*Cammock, wild liquorice, stinking Tommy, ground furze, land whin; spiny rest-harrow, *Ononis spinosa* of Linnaeus, Grieve’s *Ononis arvensis*; in pharmacy *Ononidis radix*, the root*

**Known today as.** *Ononis spinosa*, a woody plant of the legume family of arable and waste ground, half a yard or a yard high, with small roundish dark-green leaves and twigs that are “without thorns while they are young; but afterwards armed in sundry places, with short and sharp thorns,” as Culpeper describes it, and pale purplish pea-flowers in July. Its root is blackish without and whitish within, “as hard as an horn when it is dried,” and runs deep. The root is the medicine.

Kind: Plant

> **Caution.** Not for children under twelve, for want of data, nor where a reduced fluid intake is recommended, as in severe heart or kidney disease. Plenty of fluid should be drunk with it; fever, painful urination, spasms, or blood in the urine call for a doctor.

## What was it used for?

A remedy for the urine and the stone. Culpeper calls it “singularly good to provoke urine when it is stopped, and to break and drive forth the stone,” the powdered bark of the root taken in wine; with vinegar as a gargle it eased toothache, and its decoction opened obstructions of the liver and spleen. Grieve adds that the young shoots were once boiled, eaten in salad, or pickled, and that in medicine it was given for stone in the bladder “and to subdue delirium.”

## What does modern science say?

The European Medicines Agency’s herbal committee accepts the root as a traditional herbal medicine, “exclusively based upon long-standing use,” to increase the amount of urine and so flush the urinary tract, as an adjuvant in minor urinary complaints (monograph of 2014). Its assessment report finds isoflavones, chiefly ononin and formononetin, the triterpene alpha-onocerin, sterols, and a little essential oil rich in trans-anethole.

## Pharmacognosy and toxicology

- **ononin**: chief of the isoflavones, with formononetin
- **formononetin**: 
- **-onocerin**: the chief triterpene, also called onocol
- **trans-anethole**: rich in the little essential oil

**Mechanism.** Not established in the sources read for this entry.

**Standing.** European Union herbal monograph (2014): traditional use, “exclusively based upon long-standing use,” to flush the urinary tract in minor urinary complaints.

## What lore surrounds it?

The name is a farmer’s complaint: its long, thickly matted root, Grieve says, “will arrest the progress of the harrow.” The Latin *Ononis* she takes from Greek *onos*, an ass, the plant being a favourite food of the donkey. Its root yields a sweet, viscid juice, and wild liquorice is among its names. A tradition, she records, made it the plant from which the crown of thorns was plaited for the Crucifixion, and it was held “obnoxious to snakes.”

## What did the older authorities say?

**Nicholas Culpeper.** “It is under the dominion of Mars.” He reports Matthiolus as saying that the powder taken for three months together cured the ‘fleshy rupture,’ and “hath cured some which seemed incurable by any other means than by cutting or burning,” and he gives a water distilled from four pounds of the sliced root steeped in a gallon of Canary wine, “singularly good for all the purposes aforesaid, and to cleanse the urinary passages.”

## Sources

- Grieve, M. *A Modern Herbal*, “Rest-Harrow.” As published on botanical.com.
- Culpeper, N. *The Complete Herbal*, “Rest Harrow, or Cammock.” Project Gutenberg, 49513.
- European Medicines Agency, Committee on Herbal Medicinal Products. *European Union herbal monograph on Ononidis radix (Restharrow root)*. EMA/HMPC/138317/2013, 25 March 2014.
- European Medicines Agency, Committee on Herbal Medicinal Products. *Assessment report on Ononidis radix*. EMA/HMPC/138316/2013, 24 March 2014.
- European Medicines Agency, Committee on Herbal Medicinal Products. *European Union herbal monograph on Ononidis radix (Restharrow root)*. EMA/HMPC/138317/2013, 25 March 2014.
- European Medicines Agency, Committee on Herbal Medicinal Products. *Assessment report on Ononidis radix*. EMA/HMPC/138316/2013, 24 March 2014.

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*Rest-harrow.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-16. The Thinking Press. https://thethinkingpress.org/materia-medica/rest-harrow

Historical description, not medical advice.