Red dock is native to Europe although not to Italy and the Balkans, and to Northern Asia . As its botanical name suggests it likes living on the edges of swampy ground and can be found in damp ditches and along margins of fields. It can grow up to 6 feet tall when it is in flower during July and August. As the English name says, it has red flowers and these give way in September to red-cased seeds. It is related to Rumex acetosella or sorrel and more distantly to rhubarb as they are all members of the Polygonaceae family of plants. It is also closely related to yellow or crispy dock and to the common dock (Rumex obtusifolia) which is the antidote to nettle stings.
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The root can be harvested in spring when it is said to be at its most potent in medical terms, and dried for later use. The tannin in the plant makes it a useful astringent and can be used for diarrhoea and stomach upset, while the anthraquinones in the plant make it a good laxative, which is milder than senna and, of course jamalgota. If you take an overdose of the plant you will suffer nausea, stomach pains and gastric problems and perhaps dermatitis if used externally.
Culpeper recommended the red dock or bloodwort: -
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He emphasizes this by ending his description of the docks by saying: -
“Bloodwort is exceeding strengthening to the liver, and procures good blood, being as wholesome a pot herb as any growing in a garden.”