← The ApothecaryPolygonaceaeroot, leaves, seedsFact-checked 24 October 2026

Significant riskContains oxalic acid. A 53-year-old man died 72 hours after eating the plant. He had stomach symptoms, severely low blood calcium, metabolic acidosis and acute liver failure, and oxalate crystals were found in his liver and kidneys. Sheep have died of acute oxalate poisoning after eating curly dock. A genus review warns that the cooking water, where oxalate collects, should not be drunk.In an emergency, call your local emergency number or poison centre.

Curled dock

Rumex crispus

Also calledYellow dock · Curly dock · Štavalj (Serbian)

In older monographsLapathum crispum

A common weedy dock, native to Europe and Asia and now found worldwide. Its yellow root has been used as a laxative, astringent and 'blood purifier', and many Native American peoples used it as a poultice for sores and swellings. No human trials were found. The plant contains oxalic acid and laxative anthraquinones, and one person is reported to have died after eating it.

What it is used for

Constipation
Traditional
Cherokee people took a root infusion for constipation, and Iroquois, Micmac and Shoshone people took the root as a purgative. The root contains anthraquinones such as emodin and chrysophanol, a class with laxative action, but no clinical studies were found.^1,2,3
Wounds and cuts
Traditional
Pounded or powdered root was applied to sores, cuts, ulcers and abrasions by Cheyenne, Chippewa, Ojibwa, Paiute and Blackfoot people, among others. Extracts of the plant were antibacterial and antioxidant in lab tests.^1,2,3
Diarrhoea
Traditional
A Cherokee root infusion was taken for dysentery, and an Iroquois compound root decoction for bloody diarrhoea; Paiute people ate the boiled seeds for diarrhoea. The traditional description of the plant as an astringent fits these uses, but they have not been tested.^1,2
Liver health
Traditional
Delaware people used the root for jaundice, and Shoshone people for liver complaints; a 2022 paper also records its medicinal use for jaundice and related liver diseases. A dichloromethane root extract inhibited the growth of liver cancer cells (HepG2) in the lab. There are no human data.^1,5,3
Arthritis and joint pain
Traditional
Paiute and Shoshone people put a poultice of pulped root on rheumatic pains and swellings, and Blackfoot people put mashed root on swellings. Untested.¹
Fluid retention
Traditional
In 19th- and 20th-century Serbian folk medicine, the root was applied as a compress for swelling (oedema).⁴

How it is prepared

decoction

Root boiled in water, taken by mouth in several Native American traditions (as a laxative, blood purifier or tonic).

Constipation

poultice

Fresh pulped or dried and pounded root, moistened and laid on sores, burns or swellings.

Wounds and cuts · Arthritis and joint pain

Amounts are as recorded by the named source, not a recommendation.

Safety

Pregnancy: Insufficient data
Breastfeeding: Insufficient data

Do not use if

Kidney stones, gout, arthritis or hyperacidity (Rumex genus review, because of oxalate)

Side effects

Nausea, vomiting, diarrhoea and low potassium
Rare symptomatic thrombocytopenia (low platelets) reported
Allergic reactions

In the healing traditions

Indigenous North American
Curly dock
Cherokee: root infusion for constipation, dysentery and 'for blood'; leaves rubbed in the mouth for sore throat. Iroquois: decoctions for bowel trouble, piles, kidney trouble and as a women's tonic. Cheyenne: dried-root infusion for bleeding from the lungs; root poultice for wounds. Paiute and Shoshone: root poultice for burns, bruises and rheumatic swellings; decoction as a blood purifier and tonic. Delaware: root for jaundice.
Native American Ethnobotany Database (Hamel & Chiltoskey 1975; Herrick 1977; Grinnell 1972; Train et al. 1941; Tantaquidgeon 1942, 1972)
European folk medicine
Štavalj (Serbia)
Root used as a compress for oedema.
Serbian ethnographic sources of the 19th–20th centuries (reviewed by Živković et al. 2026)
Modern pharmacology
Rumex crispus root
In the lab, extracts have been studied for antimicrobial, antioxidant, anti-inflammatory, anti-osteoporotic and α-glucosidase-blocking effects. A 2024 review records traditional use in various countries as an astringent, laxative, diuretic, mild tonic, 'blood cleanser', spasmolytic and cholagogue.

Active compounds

emodin, chrysophanol, physcion: anthraquinones of the root, the class of compounds behind senna-type laxatives; chrysophanol and physcion blocked α-glucosidase in the lab
oxalic acid: present in Rumex leaves and roots; in large amounts it binds calcium and can cause poisoning and kidney stones
quercetin glycosides and other flavonoids: antioxidant in lab assays

History

Dock roots were a common 'blood medicine' among Native American peoples from the Delaware and Iroquois in the east to the Paiute and Shoshone of Nevada. In 1990, Barcelona pathologists described a fatal case of curled dock poisoning and warned about using these plants as food or medicine.

Sources

Reference, not prescription. Nothing here is medical advice. Herbs can interact with medicines and be dangerous in pregnancy; tell your doctor or pharmacist about anything you take.