IN common language the term Geranium includes all that extensive tribe of plants comprised by the old genus of that name, and principally characterised by their beaked fruit and five seeds which are scattered by means of awns. L'Heritier has divided this family into three distinct genera, under different orders in the artificial class Monadelphia. These are Erodium, having five stamens, five nectariferous scales and glands, and the awns of the fruit twisted and bearded. Pelargonium, which includes most of the Cape species so commonly cultivated among us, having about seven stamens, an irregular corolla, and a nectareous tube running down the peduncle. Lastly, Geranium having ten stamens, a regular corolla, five nectariferons glands at the base of the longer filaments, the awns of the fruit neither bearded nor twisted. To this division belongs the plant under consideration, which has the following specific character. Erect, hairy backward; stem forked; leaves opposite, three or five parted, cut; peduncles mostly two flowered; petals, obovate, entire.
Jussieu has formed a natural order by the name of Gerania, which nearly corresponds to the Gruinales of Linnaeus.
Although we have few species of Geranium in the United States, yet the present species, by its extensive diffusion, is a sufficient representative of the race. It is very common in low grounds, about Boston and Philadelphia, in the Carolinas, and in the western country upon the banks of the Ohio and Illinois.
The root of Geranium maculatum is perennial, horizontal, thick, rough and knobby. In most plants it sends up a stem and several root leaves. The leaves are spreading, hairy, divided in a palmate manner into three, five, or seven lobes, which are variously cut and toothed at their extremities; those of the root are on long petioles, those at the middle of the stem opposite and petioled, those at the top opposite and nearly sessile. The stem is erect, round, hispid with reversed hairs, dichotomous, with a flower stalk in the fork. Stipules and bractes linear, dilated at base. Peduncles round, hairy, swelling at base, generally two flowered. Calyx of five oblong, ribbed, mucronated leaves, with the parts, which are outermost in the bud, hairy. Petals five, obovate, not emarginate, of a light purple colour, which is deeper when the plant grows in the shade, marked with green at the base. Stamens ten, erect or curving outward, the alternate ones a little longer, with nectariferous glands at the base; filaments dilated and united together at base; anthers oblong, deciduous, so that the number frequently appears less than ten. Germ ovate; style straight, as long as the stamens; stigmas five, at first erect, afterwards recurved. Capsule five seeded, surmounted by a long straight beak, from the sides of which when ripe are separated five thin, flat awns, which curl up, having cast off the seed contained in the cell at the base of each.
The root of the Geranium, which is the part to be used in medicine, is internally of a green colour, and when dry is exceedingly brittle and easily reduced to powder. It is one of the most powerful astringents we possess, and from its decided properties, as well as the ease of procuring it, it may well supersede in medicine many foreign articles of its class which are consumed among us. The experiments, which I have made upon this root, have been principally directed to the examination of its astringent qualities.
A drachm of the powdered root was steeped in two ounces of cold water and the infusion filtrated. Successive portions of water were added until the liquid came off colourless and tasteless. The collected infusion had a pale greenish colour, and a styptic, austere taste. It did not redden vegetable blues.
To half this infusion was added a drachm of gelatin in solution. The liquor instantly became of a milky whiteness, and a copious white precipitate was thrown down. This precipitate was dried and assumed a semi-transparent, horny appearance. Its weight was eleven grains.
A drachm of kino treated in the same manner was rendered turbid, but gave a very scanty precipitate with the gelatin.
To portions of the same infusions was added a solution of the muriate of tin. In both of them a greenish precipitate was formed, but that of the Geranium was much the most immediate and abundant.
The sulphate of iron struck a dark purple colour with the infusion of Geranium. The compound remained principally suspended at the end of twenty four hours, and when used in writing had the appearance of common ink, but in a few days changed to a dull brown colour. A portion of the fresh infusion was distilled, but the liquid which came over was not altered in colour by the sulphate of iron.
The above experiments indicate the presence of tannin and gallic acid, the former in large quantities, in the root of the Geranium. The proportion of tannin seems considerably to exceed that in the kino of the shops. The gallic acid is indicated by the dark precipitate remaining in solution. This is Berthollet's criterion. It differs however from the acid of oak galls in not reddening vegetable blues, and not passing over in distillation.
Alcohol and proof spirit readily dissolve the active constituents of the Geranium. The tincture has a great sensible astringcncy, and is a convenient mode of keeping the article for use.
The Geranium has been repeatedly employed in medicine by various practitioners in this country. I have found it useful in a number of cases, where astringents were capable of rendering service. It is particularly suited to the treatment of such discharges as continue from debility after the removal of their exciting causes. The tincture forms an excellent local application in sore throats and ulcerations of the mouth.
Its internal use has been recommended in dysentery and cholera infantum, but astringents are not always admissible in these complaints, at least in their early stages, during the existence of much active inflammation, or during the presence of any substance requiring to be removed.
The Geranium may be used in powder in extract, or in tincture. Its doses are similar to those of kino and catechu, a drachm or two of the tincture, twenty or thirty grains of the powder, and a quantity somewhat less of the extract.
Geranium maculatum, Sp. pl.
Willdenow, iii. 705.
Gronovius, Virg. 101.
Walter, Carol. 175.
Michaux, ii. 38.
Pursh, ii. 448.
G. caule erecto, herbaceo, foliis oppositis, quinque partitis, incisis &c. Cavanilles, diss. t. 86, f. 2.
G. batrachioides, Americanum, maculatum, floribus obsolete coeruleis, Dill. Elth. 158. t. 131, f. 159.
Bart. Coll. 7.
Cutler, Mem. Amer. Acad. i. 469.
Thacher, Disp. 224.
American Medical Botany, 1817-1821, was written by Jacob Bigelow, M. D.