The curly dock, curled dock or yellow dock, (Rumex crispus) is a perennial flowering plant native to Europe and Western Asia. It occurs widely on waste and cultivated ground and is noted for attracting wildlife. It is now widely distributed throughout and is considered to be an invasive species in many areas, including the Americas and Australasia. It can be used as a wild leaf vegetable. Dock leaves, raw or cooked, are an excellent source of both vitamin A and vitamin C, as well as a source of iron and potassium. However, care is required in the consumption of he leaves since they contain of high levels of oxalic acid which can irritate the urinary tract and increase the risk of developing kidney stones. The seeds of the plant are also edible and can be used as a coffee substitute.
In traditional medicine all parts of the plant can be used, though the root is the most active part. the root has been used for treating anemia, due to its high level of iron. It is often used together with with stinging nettles. Both the leaves and root can act as a mild laxative. The plant has also been used as a poultice for the treatment of certain skin conditions, sores, ulcers etc. As part of the homeopathic pharmacopoeia it is used mainly for the treatment of certain types of coughs.