Rumex. Yellow dock, Curled dock. Rumex crispus, Rumex obtusifolius.
Rumex. N. F. IV. Yellow Dock. Curled Dock. Radix Lapathi.—Rumex was official in the U. S., 1890, and has been admitted to the N. F. IV and is defined as "The roots of Rumex crispus Linné, or of Rumex obtusifolius Linné (Fam. Polygonaceae), without the presence of more than 5 per cent. of stem bases." N. IV. The roots of rumex are officially described as "Usually split longitudinally or cut into transverse pieces about 2 cm. in length. The entire root, nearly simple, slightly tapering, with few if any rootlets, somewhat twisted, up to 30 cm. in length and 7 cm. in diameter, externally reddish-brown or grayish from adhering soil, finely annulate above, deeply wrinkled longitudinally, marked with small indented root scars which are often transversely elongated and with occasional stem scars or remains of stem, the latter being hollow and finely striated; leaf buds few, obconical; fracture short and dusty, somewhat fibrous. The transverse section exhibits a yellowish or brownish cortex and a whitish or yellowish wood which is finely radiate in the outer portion. When examined under the microscope, it exhibits a thick cortex with several layers of cork, beneath which is an interrupted row of stone cells; a distinct cambium; and vascular bundles with few fibers. The powder, when examined under the microscope, shows calcium oxalate crystals in rosette aggregates from 0.025 mm. to 0.06 mm. in diameter; numerous starch grains ellipsoidal or narrowly elongated, sometimes truncate, up to 0.025 mm. in length; stone cells from 0.04 mm. to 0.2 mm. in diameter, with walls somewhat lamellated, from 0.008 mm. to 0.025 mm. in thickness and with few simple pores; sclerenchymatous fibers few, thin-walled with simple pores; tracheae up to 0.1 mm. in width with scalariform or reticulate thickenings of the wall; cork cells light brown. Rumex yields not more than 10 per cent. of ash." N. F. IV.
Several species of rumex have sour leaves, and are distinguished by the common name of sorrel from the others, which are called dock. Of the former, Rumex Acetosa L., or common English sorrel, formerly held a place in the London and Dublin Pharmacopoeias. R. Acetosella L. is the common sorrel of our fields, though supposed to have been originally introduced from Europe. The leaves of both these plants are agreeably sour to the taste, and owe their acidity to acid potassium oxalate with a little tartaric acid. They quite lose this taste in drying. They are refrigerant and diuretic, and may be used advantageously as an article of diet in scurvy. For this purpose they are prepared in the form of salad. The juice of the leaves forms with water an agreeable acidulous drink, sometimes used in fevers. Taken very largely, the leaves are said to have produced poisonous effects. R. scutatus L., of Europe, Northern Africa, Asia Minor, and the Caucasus, also ranks among the sorrels (French sorrel).
Of the proper docks, the roots of R. silvestris Wallr., an European plant, and of R. conglomeratus Murr., R. aquaticus, R. sanguineus L., and R. Patientia L., belonging both to Europe and to the United States, may be employed indiscriminately with those of the R. crispus L., which was formerly recognized by the U. S. Pharmacopoeia. R. Britannica L., and R. obtusifolius L., were formerly official. R. Hydrolapathum Hudson, which is the R. aquaticus of the old Dublin Pharmacopoeia, is thought to be the Herba Britannica of the ancients, celebrated for the alleged cure of scurvy and diseases of the skin. The docks are herbaceous plants with perennial roots, and especially distinguished by the sheathing petioles of the leaves. The flowers are small, mostly green, and occur in terminal or axillary panicles.
Dock root, from whatever species derived, has an astringent, bitter taste, with little or no odor. The leaves of most of the species are edible when young, and are occasionally used like spinach. They are somewhat laxative, and form an excellent diet in scorbutic cases. The roots are used to dye a yellow color. According to J. H. Salisbury (N. Y. Journ. Med., March, 1855), the petioles of the leaves contain nearly one per cent. of oxalic acid; the cortical part of the root, which is the most active, yielded, on analysis, starch, a little sugar, albuminous matter, gummy matter, bitter extractive, tannic acid of the kind which gives green precipitates with the salts of iron, lignin, and various salts. The root yields its virtues to water and to alcohol, but is injured by long boiling.
Dock root is astringent, gently tonic, and has been supposed to have alterative properties, making it useful in skin diseases and even syphilis. From the root of R. Nepalensis Wall., which is largely used in Madras as an astringent for medicinal purposes and for dyeing, O. Hesse has separated three crystalline substances to which he gives the names of rumicin, nepalin, and nepodin. (P. J., lvi; also Proc. A. Ph. A., 1896, 551.) According to Tutin and Clewer (Trans. Chem. Soc., 1910, xcvii) the R. Eckolianus Meissner, a South African herb, contains chrysophanic acid, emodin, and allied products, and is mildly purgative. Tschirch and Well found small quantities of emodin and chrysophanic acid with lapathinic acid, C20H18O14, in the root of R. obtusifolius. (A. de Pharm., 1912, No. 1, 20.) R. aquaticus and R. Britannica are the most astringent. The roots of some species unite a laxative with the tonic and astringent property, resembling rhubarb somewhat in their operation. Such are those of R. crispus and R. obtusifolius; and R. alpinus L., has in some parts of Europe the name of mountain rhubarb. This resemblance is not singular, as the two genera belong to the same natural family. A. Gilbert and P. Lereboullet have discovered a remarkable property of Rumex crispus. For the roots of this plant are said to possess the power of taking up the iron present in the soil, and fixing it in the form of organic compounds of iron. By watering the plants with a solution of iron carbonate, roots are said to be obtained which contain 1.5 per cent. of iron. Rumex is said to give good results in the treatment of chlorosis and anemia. The authors gave the dried and powdered root during meals in doses of fifteen to forty-five grains (1-3 Gm.), in view of their good results they regard it as a valuable iron medicine. Dock root is given in powder or in decoction. Two ounces (62 Gm.) of the fresh root bruised, or one ounce (31 Gm.) of the dried, may be boiled in a pint (480 mils) of water, of which two fluidounces (60 mils) may be given at a dose, and repeated as the stomach will bear it. George G. Flemyng (L. L., i, 1896) reported the death of two sisters, aged respectively five and six and a half years, preceded by symptoms of oxalic acid poisoning as the result of the ingestion of sorrel leaves.