Uses
These plants have many uses. Broad-leaved dock (Rumex obtusifolius) used to be called butter dock because its large leaves were used to wrap and conserve butter.
These plants are edible.
Rumex hymenosepalus has been cultivated in the Southwestern US as a source of tannin (roots contain up to 25 percent tannin), for use in leather tanning, while leaves and stems are used for a mordant-free mustard-colored dye.
The leaves of most species contain oxalic acid and tannin, and many have astringent and slightly purgative qualities. Some species with particularly high levels of oxalic acid are called sorrels (including sheep's sorrel, Rumex acetosella, common sorrel, Rumex acetosa and French sorrel, Rumex scutatus), and some of these are grown as pot herbs or garden herbs for their acidic taste.
In Western Europe, dock leaves are a traditional remedy for the sting of nettles, and suitable larger docks (such as broad-leaved dock Rumex obtusifolius or curled dock Rumex crispus) often grow conveniently in similar habitats to the common nettle (Urtica dioica).
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