This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Yellow Dock, Rumex crispus. Not official anywhere. Contains tannin and chrysophanic acid, thus resembling rhubarb in its pharmacology. The root is tonic, astringent, and slightly laxative, though less laxative and more astringent than rhubarb. Rumex is used as an alterative in various chronic affections, especially of the skin and lymphatics. It is of some value in chronic dyspepsia, but rhubarb usually serves better.
The fl. is given in doses of 5 to 30 minims.