The fresh herb of Polygonum Hydropiper, Linné.
COMMON NAMES: Smartweed, Water pepper.
ILLUSTRATION: Britton and Brown, Illustrated Flora of Northern United States, Canada, and the British Possessions, Fig. 1333.
Botanical Source.—This is an annual, glabrous plant, with a simple or branched, erect stem, of a red, reddish, or sometimes greenish color, from 8 inches to 2 feet high. The lanceolate, or oblong-lanceolate, leaves are from 1 to 4 inches long, acute or acuminate at apex, ciliate, undulate, or slightly crisped, punctate, and very acrid. The ocreae are cylindric, fringed with short bristles, or occasionally slightly pubescent, generally swollen at the base on account of the development of flowers within. The flowers are borne in a panicled raceme, which is narrow, drooping, interrupted, and from 1 to 3 inches long. The green calyx is usually 4-parted (3 to 5), and conspicuously punctate; stamens 4, occasionally 6; style 2 or 3-parted, short; fruit a lenticular achene, triangled, broad-oblong or ovoid, slightly gibbous, dull and granular (Britton and Brown).
History.—Polygonum Hydropiper is a well-known, intensely acrid plant, found growing in nearly all parts of the United States, in ditches, low grounds, among rubbish, and about brooks and water-courses, flowering in July, August, and September. That growing in our section of the country being naturalized from Europe; Britton and Brown state that it is perhaps indigenous in the far northwest. There are many species of Polygonum (at least 38), some of which, although possessing similar virtues, differ materially in medical potency. The whole plant (P. Hydropiper) is medicinal, and has a biting, pungent, acrid taste, and imparts its virtues to alcohol or water. Age renders it inert, and heat impairs its medicinal qualities. It should be collected and made into a tincture while fresh.
Chemical Composition.—According to analysis by H. Trimble and H. J. Schuchard (Amer. Jour. Pharm., 1885, p. 21), the tops and leaves contain 3.46 per cent of tannin, 7.4 per cent of ash, and resin, wax, gum, sugar, etc. The active (pungent) principle was found to disappear upon heating; it was contained in the alcoholic extract of the drug, after successive treatment with petroleum spirit and ether. Dr. C. J. Rademaker, however, asserted (ibid., 1871, p. 490; and 1886, pp. 279 and 373) that the active principle consists of crystallizable polygonic acid, which, when pure, differs in its reactions from those for tannic or gallic acids. It is soluble in water, less soluble in ether, and insoluble in petroleum spirit. The heat of the water-bath does not destroy any of its properties.
Action, Medical Uses, and Dosage.—Water pepper is stimulant, diuretic, emmenagogue, antiseptic, diaphoretic, and vesicant. Dr. Eberle found it very efficient in the dose of a teaspoonful of the saturated tincture, repeated 4 or 5 times a day, or from 2 to 5 grains of the aqueous extract, in amenorrhoea; probably, an alcoholic extract would be found more active. He states that the use of it caused an increase of the heat of the body with a kind of formication, with bearing down and sense of fullness in the pelvic region. The infusion, in cold water, has been found serviceable in gravel, colds, and coughs, and in milk-sickness, and, mixed with wheat-bran, in bowel complaints. In Asiatic cholera, the patients, wrapped in a sheet moistened with a hot decoction, are said to have been much benefited, and to have recovered. In combination with sulphate of iron and gum myrrh it is said to have cured epilepsy—probably dependent on some uterine derangement. Externally used as fomentation (simmered in water and vinegar) in gangrene. The infusion, or a fomentation of the leaves, has been beneficially applied in chronic ulcers and hemorrhoidal tumors, also as a wash in chronic erysipelas and inflammations, and as a fomentation in tympanites and flatulent colic. The fresh leaves, bruised with the leaves of May-weed, and moistened with the oil of turpentine, and applied to the skin, will speedily vesicate. The ashes of the plant combined with the ashes of the garden thyme (Thymus vulgaris) are, it is said, used by many empirics, injected, in solution, into the bladder as a solvent for gravel and stone; hazardous and doubtful treatment. The infusion, in cold water, forms an excellent local application in the sore mouth of nursing women, and in mercurial ptyalism. The decoction or infusion, in hot water, is not so active as when prepared in cold or warm water. Dose, of the infusion, from 2 to 4 fluid ounces; of the saturated tincture, from 1 to 4 fluid drachms, 3 or 4 times a day: specific polygonum, 1 to 60 drops.
Related Species.—Polygonum Persicaria, Linné, called Smart weed, Lady's thumb, or Spotted knotwood, possesses similar but inferior medicinal properties, and may be distinguished from the above by the deeper-green or purplish color of the whole plant, a brownish, heart-shaped spot near the center of the leaf, and its rose-colored flowers, in short, dense, terminal spikes. It has a feebly astringent, saline taste, and, at one time, was considered antiseptic.
Polygonum arifolium, Linné, Sickle grass, Halbert-leaved tear-thumb, or Hastate knot grass. —This plant grows in low and wet grounds throughout the United States, flowering from June to September. An infusion, in cold water, is a powerful diuretic, useful in uric acid and phosphatic gravel, strangury, gonorrhoea, and all urinary affections; it must be drank freely. Also of service in catarrh of the bladder, and in muscular debility of this organ.
Fagopyrum esculentum, Moench (Polygonum Fagopyrum, Linné; Fagopyrum Fagopyrum [L.], Karsten), or Common buck-wheat, may be used as follows, to recall the flow of milk in the breasts of nurses, where it has disappeared for several days. Stir into any amount of buckwheat flour, a sufficient quantity of buttermilk to form a poultice; warm it, but be careful not to boil or make it hot. Apply it thus warm, over the whole breast, and renew it every 4 or 6 hours. Sometimes it requires to be thus used for 3 or 4 days before its effect will be produced; usually, however, 24 hours will be sufficient. The seeds, deprived of their husks, contain about 70 per cent of starch and 13 per cent of gluten (Zenneck).
Polygonum erectum, Erect knot grass, Bird knot grass, Goose grass, Bird weed.—This is a perennial herb, common to the western and middle states and British America. It is found in abundance about country dooryards, roadsides, waste places, damp soils, etc., blossoming from June to October. This plant, in infusion, has been found highly efficient in the treatment of diarrhoea, and especially in summer complaint of children.
Polygonum amphibium, Linné, Water persicaria.—A variable plant growing in wet situations. It may be readily cultivated, and has been recommended for tanning purposes, as the dried stems yield over 17 and the root above 21 per cent of tannin.
Polygonum punctatum, Elliott (Polygonum acre, H. B. K., not of Lamarck), Dotted or Water smart weed.—A smooth annual or perennial, acrid species, found in swamps and other wet places throughout the most of North America. Has been used for similar purposes as smart weed.
Polygonum hydropiperoides, Michaux (Polygonum mite, Persoon), is Mild water pepper, found in wet soil and swamps throughout the United States, and flowering from June to September. It has decided stimulating properties. Eberle pronounces it a most active and certain emmenagogue (see Amer. Jour. Pharm., 1883, p. 195).
BISTORTA, Bistort.—The rhizome of Polygonum Bistorta, Linné, or Snakeweed. This plant is found in swampy places throughout the northern countries of the globe, being present in the United States northward from Colorado. The rhizome, which is recognized in some European pharmacopoeias, is blackish-brown, peculiarly distorted, S-shaped, sub-annulate, reddish internally, and breaks with an almost smooth fracture. When broken it exhibits a large pithy center, surrounded by a single circle of many small, woody bundles, enveloped by a thicker bark. It is odorless, but powerfully astringent in taste, as it contains tannin to the extent of 21 per cent (Bowman, 1869). P. Krebs found tannin (15 per cent), resin (0.30 per cent), wax and fat, starch, dextrin, dextrose, mucilage, gallic acid, etc. (Amer. Jour. Pharm., 1891. p. 476). It is employed where a vegetable astringent such as geranium, is indicated.