DOCK, Lapathum, a sub-genus of the genus rumex, the other species of which are generally called sorrel (q.v.), containing those which are not acid, and of which the flowers are hermaphrodite. They are large perennial herbaceous plants, natives chiefly of temperate climates, with large generally lanceolate or ovate leaves, and panicles of small greenish flowers. They have great tap-roots, and are with difficulty eradicated from pastures. They also multiply rapidly by seed. The best mode of dealing with them, is generally found to be repeated cutting away of their leaves and shoots, by which the plants are killed. Many of the species prefer watery places. A number are natives of Britain, and several of the European ones have found their way to North America, where they have become troublesome weeds, a number of really indigenous species being also found there. Useless and even troublesome as the D. is generally esteemed,
yet the large astringent roots are capable of being beneficially employed in medicine; and those of the great water D. (B. hydrolapathum) in particular—for which the Druids entertained a superstitious veneration—are administered as an antiscorbutic. They are also employed in rheumatism, and sometimes as a styptic, sometimes to form an astringent gargle, and sometimes as a dentifrice. R. alpinu-s is called 3IoxR's RuunAnn, and its root was formerly employed instead of rhubarb, but is less powerful. It is a native of the Alps, and has been found in several places in Britain.—The roots of docks have been sometimes used in dyeing, and give " a great variety of shades, from straw color to a pretty fine olive, and a fine deep-green to cloths which have been previously blued."