Polygala senega. Seneca Snake root.

Botanical name: 

Pl. 30. Polygala senega. Also see Polygala rubella - Polygala senega.

The Seneca snake root has attracted so general an attention from the medical public, as to have become an article of exportation to Europe, and one which holds a regular place in the druggist stores. The plant which produces it has nothing to boast on the score of elegance, and little to attract attention independent of its medicinal virtues. It grows in most latitudes of the United States, especially in the mountainous tracts. The specimen, from which our drawing was taken, was gathered on the borders of Lake Champlain.

The genus Polygala has a five leaved calyx, two of the leaves wing like, and coloured. Capsule obcordate, two celled, and two valved.

The species Senega has erect, smooth, simple stems, with alternate, lanceolate leaves, broadest at base. Flowers slightly crested.

Class Diadelphia, order Octandria; natural orders Lomentaceae, Linn. Pediculares, Juss.

The Polygala senega has a firm, hard, branching perennial root, consisting of a moderately solid wood, and a thick bark. This root sends up a number of annual stems, which are simple, smooth, occasionally tinged with red. The leaves are scattered, nearly or quite sessile, lanceolate, with a subacute point, smooth, paler underneath. Flowers white, in a close terminal spike. The calyx, which in this genus is the most conspicuous part of the flower, consists of five leafets, the two largest of which, or wings, are roundish-ovate, white, and slightly veined. Corolla small, closed, having two obtuse lateral segments, and a short crested extremity. Capsules obcordate, invested by the persistent calyx, compressed, two celled, two valved. Seeds two oblong-obovate, acute at one end, slightly hairy, curved, blackish, with a longitudinal, bifid, white appendage on the concave side. The spike opens gradually, so that the lower flowers are in fruit while the upper ones are in blossom.

The rose coloured variety of this plant, as it has been considered by Michaux, proves to be a distinct species. Some species which I possess from Carolina have branching, pubescent stems, and very long, loose spikes. The flowers are several times larger than those of P. senega.

The root of the Polygala senega has an unpleasant and somewhat acid taste. After chewing, it leaves a sensation of acrimony in the mouth, and still more in the fauces, if it has been swallowed. These properties it communicates fully to water upon boiling. The process of decoction does not appear to dissipate any of its power, since the distilled water is destitute of the taste and smell of the plant. Alcohol dissolves a substance, apparently of the resinous kind, giving a precipitate when water is added. Iron produces little change in solutions of this root, and gelatin occasions no alteration whatever.

Medicinally administered, the Seneca snake root is sudorific and expectorant in small doses, and emetic and cathartic in large ones. Its most usual mode of exhibition is in decoction, which may be made of suitable strength by boiling an ounce of the root in a pint and an half of water, till it is reduced to a pint. This preparation may in most cases be given in doses of a table spoonful and upward without disturbing the stomach.

The first reputation of the Seneca root was one which it divides with a multitude of other plants, that of curing the bite of the Rattlesnake. A reward was given by the legislature of Pennsylvania to Dr. Tennent for the promulgation of this supposed property. When, however, we consider the number of cases of recovery from the bite of this serpent, under every variety of treatment, we cannot avoid the conclusion, that these injuries are not necessarily dangerous, and that spontaneous recoveries are perhaps as frequent as those which are promoted by medicine.

More certain success attends the use of the Seneca in pneumonia and some diseases related to it. In the advanced stages of pneumonic inflammation, after venesection and the other usual remedies have been carried to their proper extent; and the cough still remains dry and painful, while the debility of the patient forbids further depletion; in these cases, I have often found a decoction of the Seneca root to afford very marked relief by promoting expectoration, and relieving the tightness and oppression of the chest. Various medical writers have spoken favourably of its employment in these cases, among whom are Lemery and others, in the Memoirs of the French Academy. It has been found injurious, from its stimulating properties, when given at too early a stage, or during the prevalence of much acute inflammation.

Benefit has been derived in asthma from the use of this plant. The following is Dr. Bree's opinion, quoted from his treatise on that disease. "Decoction of seneka is eminently useful in the first species, administered to old people, but in the paroxysm of young persons, I have found it too irritating. This distinction applies to convulsive asthma purely uncomplicated, but the disease is frequently observed in middle aged and elderly persons, to take the character of peripneumonia notha in the winter and spring, and seneka is then the most useful medicine that I have tried. In such cases, it should be united with acetated ammonia, during the febrile state, and as this state gives way, the addition of squill, and camphorated tincture of opium, will be found to promote expectoration, perspiration, and urine in a most powerful manner."

In croup, this medicine was introduced into notice by Dr. Archer of Maryland. He speaks with much confidence of its utility in that disease, particularly in promoting the separation and discharge of the membrane formed in the trachea of patients affected by it. Such a membrane, however, does not exist in all cases of croup. And in the early part of the complaint it may be questioned, how far a medicine, which acts as a stimulant to the fauces and neighbouring organs, is entitled to reliance, in a local inflammation of the trachea. It ought not from such a reliance to exclude more active remedies, especially venesection. Dr. Archer's mode of administering it is to give a tea-spoonful of a strong decoction every hour or half hour, according to the urgency of the symptoms, and during the intervals, a few drops occasionally, to keep up a sensible action of the medicine upon the mouth and throat, until it acts as an emetic or cathartic.

In various forms of dropsy, the Seneca root has been resorted to with advantage, and has received the commendations of Percival, Millman, and some others. Its cathartic and diuretic effects are very considerable, when regularly persevered in, in quantities as large as will set easily on the stomach; and have in various instances effected the dissipation of dropsical swellings.

In chronic rheumatism, this root sometimes does good by its universally stimulant and diaphoretic effects. The following case occurred to me some time since in practice. A man labouring under severe rheumatism was ordered to take at intervals a wine glass full of a strong decoction of the Senega made from an ounce of the root in a pint of water. The patient, from a desire to expedite the cure, thought proper to drink the whole quantity at once. The consequence was the most violent vomiting and purging, which lasted the whole night, accompanied with profuse diaphoresis. The patient, as might have been hoped from the violence of the operation, was radically relieved of his disorder.

In uterine complaints, particularly amenorrhea, the Polygala senega has been found of decided efficacy. Dr. Chapman of Philadelphia is one of the authorities for its use in these cases. It must he given largely, and continued for some time.

The most common mode of exhibition of this root is in decoction, as already mentioned. It is also given in powder in doses of twenty or thirty grains. Dr. Tennent likewise employed a wine of Senega made by digesting four ounces of the root in a pound of wine, of which three spoonfuls were given at a dose.

Botanical References.

Polygala senega, Lin. Sp. pl.
Walter, Car. 178.
Woodville, ii. t. 93.
Bot. Mag. t. 1051.
Michaux, ii. 53.
Pursh, ii. 464.
Polygala caule simplici erecto, &c.
Gronovius, Virg.80.

Medical References.

Tennent, Diseases of Virginia.
Lemery, Duhamel, &c. Hist, de l'Acad. 1739, 136.
Archer, Med. & Phys. Journal, i. 83, 106.
Percival, Med. Journal, iv. 67.
Bree on Asthma, 258.
Massie, Inaug. Diss. Philad. 1803.
Thacher, Disp. 319.
N. Eng. Journal, vii. 206.


American Medical Botany, 1817-1821, was written by Jacob Bigelow, M. D.