The rhizome and rootlets of Geum rivale, Linné, and Geum virginianum, Linné.
Nat. Ord.—Rosaceae.
COMMON NAMES: (1) Water avens, Purple avens; (2) Virginia geum, Throat-root, Chocolate-root.

Botanical Source.Geum rivale, likewise known as Purple avens, is a perennial, hairy, deep-green herb, with a creeping, blackish, somewhat woody root, running deep into the ground, with numerous fibers. The stems are 1 or 2 feet high, nearly simple, erect, and slightly paniculate at top. The radical leaves are nearly lyrate, uninterruptedly pinnate, with large terminal leaflets on long hairy petioles, rounded, lobed, and crenate-dentate, and from 4 to 6 inches long. The cauline leaves are few, subsessile, from 1 to 3 inches long, and divided into 3 serrate, pointed lobes; the stipules are ovate, acute, cut, and purplish, The flowers are few, sub-globose, nodding, yellowish-purple, on axillary and terminal peduncles. The calyx is inferior, erect, purplish-brown, with 10 lanceolate, pointed segments, 5 alternately smaller than the others; petals 5, as long as the erect calyx segments, broad-obcordate, clawed, purplish-yellow, and veined. The seeds are oval, bearded, and hooked at the end (L.—W.—G.).

Geum virginianum, Linné, also known as Throat-root, Chocolate-root, etc., is also perennial, with a small, brownish, horizontal, crooked root. The stem is simple or branched, smoothish above, pubescent below, and 2 or 3 feet high. The radical leaves are pinnate, lyrate, or simple and rounded, with appendaged petioles from 6 to 8 inches long; the cauline leaves 3 or 5-lobed, softly pubescent; all the leaves are unequally and incisely dentate. The flowers are rather small, white, erect, and borne on long, diverging peduncles; the calyx is 5-cleft, with 5 smaller and exterior, alternate bracteoles; the petals 5, about the length of the calyx; the stamens numerous; filaments slender, anthers yellowish and round. The styles are many, persistent, mostly jointed, geniculate, bearded, and booked after the upper joint falls away. The fruit is an achenia, aggregated on a dry receptacle, caudate with the style (W.—G.).

History and Description.Geum rivale is common to Europe and this country, and is found growing in woods, wet meadows, and along streams, especially in the northern and middle states, and flowering in June and July. The American species differs from the European (Geum urbanum, Linné), in having the petals more orbicular on their free margin, the flowers of less size, and its leaves with deeper incisions. The fresh root is aromatic.

Geum virginianum is found in hedges and thickets, and in moist places in most parts of the United States, flowering from June to August. These plants, with some other varieties, have long been used in domestic practice. The whole herb contains medicinal properties, but the medicinal and most efficient portion is the root. The dried root of the G. rivale is scaly, jointed, tapering, hard, brittle, easily pulverized, of a reddish or purplish color, and inodorous; that of the G. virginianum, is brown, crooked, tuberculated, and brittle; both are white internally, and of a bitterish astringent taste. Boiling water or alcohol extracts their virtues, the solution becoming reddish. They have not been analyzed, but probably contain tannic acid, bitter extractive, gum, resin, etc. A weak decoction of the root of G. rivale is sometimes used by invalids as a substitute for tea and coffee. Its constituents are probably the same as those of Avens (Geum urbanum, Linné) (see Related Species).

Action, Medical Uses, and Dosage.—Tonic and astringent. Useful in all cases where there is an enfeebled state of mucous tissues, or morbid secretions therefrom. Large doses may cause emesis. Used in numerous diseases, as passive and chronic hemorrhages, chronic diarrhoea and dysentery, leucorrhoea, dyspepsia, phthisis, congestions of the abdominal viscera, intermittents, aphthous ulcerations, etc. Dose of the powder, from 20 to 30 grains; of the decoction from 1 to 2 fluid ounces, 3 or 4 times a day. Geum urbanum, or European avens, possesses similar properties (see below).

Specific Indications and Uses.—(Geum rivale). "Tearing, spasmodic, abdominal pains recurring upon taking food or exercise" (Scudder).

Related Species.Geum album, Gmelin; White geum. United States. Flowers in May and August. Used in headaches and irritable conditions of the stomach (Amer. Jour. Pharm., 1883).

Geum urbanum, Linné; Avens, European avens. Europe, growing in woodlands and shady situations, and has yellow flowers. The rhizome of this plant is hard, dark-brown, tuberculated at top, short (1 or 2 inches long and from ¼ to ½ inch thick), and has the summit beset with hairy, reddish-brown leaf scales. The fresh rhizome resembles cloves in odor, hence has been called radix caryophyllata. Internally the rhizome is whitish, surrounding a central red portion. It has many fibrous roots of a lighter brown hue. It imparts a red color to both water and alcohol. Buchner analysed it in 1844, and found a considerable amount of tannin and a a amorphous and neutral yellow mass, to which be gave the name geum bitter. He also confirmed the observation of Trommsdorff as to the presence of a greenish-yellow volatile oil (0. 04 per cent), and found that it has a clove-like odor (Rep. d. Pharm., 1844, Vol. LXXXV, p. 168 to 201).

Avens is an astringent tonic considerably employed in European practice, where it is used in intermittents, dysentery and diarrhoea, passive hemorrhages, and leucorrhoea. It is apt to derange the stomach and induce emesis if given too freely. The dose of the powder is from 20 to 60 grains, but the decoction, made by boiling 1 ounce of avens in 1 pint of water, is preferable. The dose is 1 or 2 fluid ounces

King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.