IT appears, that both North and South America give rise to this species of Arum, which is so versatile in its constitution as to bear the winters of Canada, and the perpetual summer of Brazil. In its structure it is one of our most singular vegetables, and in colour one of the most variable. It grows in swamps and damp shady woods, and is universally known among us by the names of Dragon root and Indian turnip.
The class to which the family of Arums belong, is rendered somewhat obscure by the variation of the species. Most botanists have placed them in the class Monoecia, others in Polyandria. The species under consideration is undoubtedly Polygamous. In natural arrangements, the Arums are found under the Piperitae of Linnreus and the Aroideae of Jussieu.
The genus Arum may be characterized as follows. Spathe one leaved, convolute at base; spadix naked above, bearing the organs of fructification at base; berries one celled.
The species triphyllum is polygamous; has its leaves ternate and entire; its scape bearing an ovate, acuminate, inflexed spathe; its spadix club-shaped, shorter than the spathe.
The root is round and flattened, its upper part tunicated like the onion, its lower and larger portion tuberous and fleshy, giving off numerous long white radicles in a circle from its upper edge. It is covered on the under side with a dark, loose, wrinkled skin. Leaves usually one or two on long sheathing footstalks, composed of three oval, mostly entire, acuminate leaflets, which are smooth, paler on the under side, and becoming glaucous as the plant grows older, the two lateral ones somewhat rhomboidal. Scape erect, round, green or variegated with purple, invested at base by the petioles, and by their acute sheaths. This supports a large, ovate, acuminate spathe, convoluted into a tube at bottom, but flattened and bent over at the top, like a hood. Its internal colour is exceedingly various, even in plants growing together. In some it is wholly green, in others dark purple or black. In most it is variegated, as in our figure, with pale greenish stripes on a dark ground. The spadix is much shorter than the spathe, club shaped, rounded at the end, green, purple, black, or variegated, suddenly contracted into a narrow neck at base, and surrounded below by the stamens or germs. In the barren plants, its base is covered with conical, fleshy filaments, bearing from two to four circular anthers each. In the fertile plants, it is invested with roundish crowded germs, each tipt with a stigma. Plants which are perfectly monoecious, and which are the least common, have stamens below the germs. There are also frequently found irregular, reniform substances, much larger than the anthers, of which they seem to be a disease. The upper part of the spadix withers with the spathe, while the germs grow into a large compact bunch of shining scarlet berries.
Every part of the Arum, and especially the root, is violently acrid, and almost caustic. Applied to the tongue or to any secreting surface, it produces an effect like that of Cayenne pepper, but far more powerful, so much so, as to leave a permanent soreness of many hours' continuance. Of this any one may become satisfied by a simple application of the root to his mouth. Its action does not readily extend through the cuticle, since the bruised root may be worn upon the external skin until it becomes dry, without occasioning pain or rubefaction.
The acrid property, which resides in this and other species of Arum, appears to depend upon a distinct vegetable principle in Chemistry, at present but little understood. It is extremely volatile, and disappears almost entirely by heat, drying, or simple exposure to the air. I have endeavoured, with but partial success, to obtain it in a separate state, or in any perceptible combination. The following were some of the methods by which it was attempted.
Portions of the fresh contused root were separately digested in water, in proof spirit, in alcohol, in ether, in olive oil and in vinegar. The infusions were tasted at different periods, but none of them had acquired the least acrimony from the plant.
The expressed juice of the root upon standing one minute had lost all its pungency.
A quantity of the bruised root was placed in a retort and covered with water. Heat was gradually applied, until a fluid began to collect in the receiver. This fluid had the peculiar odour of the root, but was wholly without acrimony. The same experiment was repeated with alcohol, and vinegar, and afforded similar results. In every case the liquid remaining in the retort was also without pungency.
Some slices of the root were digested in proof spirit in a close stopped phial. The portions of root retained their acrimony at the end of some weeks, but had imparted none to the spirit. At the end of two years, the root was examined and found destitute of acrimony, as were also the whole contents of the phial.
Suspecting that the acrid principle of this plant must escape in form of gas during the processes which have been mentioned, the following experiment was made. A quantity of the bruised root and stalks were placed in a vessel of water. A glass receiver was filled with water and inverted over them, and sufficient heat applied to raise the water nearly to the boiling point. From the beginning of the process, bubbles of air continued to escape from the plant, and were collected in the upper part of the receiver. In the course of half en hour, a considerable quantity of permanent gas was obtained. A part of this gas, after cooling, was transferred to a phial, in which was a small quantity of atmospheric air. On presenting a lighted paper to the mouth of this phial, it exploded with a very distinct report. Another portion of the gas was agitated with lime water, which it rendered turbid. This circumstance was probably owing to the mixture of carbonic acid disengaged from the plant, or from the water by boiling.
From the above experiments, which circumstances did not permit me to pursue, it appears that the acrimony of the Arum resides in a principle having no affinity for water, alcohol, or oil, being highly volatile, and, in a state of gas, inflammable. The products of its combustion, as well as its other affinities, remain to be investigated. [The acrimony of the Ranunculi, which approaches that of the Arum, is lost by drying, yet is soluble in water, and passes over with it in distillation. That of Polygonum hydropiper disappears in decoction and distillation. The same takes place with several other acrid plants which I have examined. Some inquiries into the acrid principle of vegetables I am in hopes to render more mature at a future period.]
The acrimony of the Arum when fresh is too powerful to render its internal exhibition safe. The roots, when dried whole, retain a small portion of their pungency, and in this state they have been given by some practitioners in the country for flatulence, cramp in the stomach, &c. also for asthmatic affections. As topical stimulants, they promise to be useful when any method shall have been discovered of fixing and preserving their acrimony. The late Dr. Barton of Philadelphia observes, that "the recent root of this plant boiled in milk, so as to communicate to the milk a strong impregnation of the peculiar acrimony of the plant, has been advantageously employed in cases of consumption of the lungs." This statement however should be qualified by the recollection, that the Arum imparts none of its acrimony to milk upon boiling. An impression of this kind can only have been received from a partial mixture of the substance of the root with the milk.
The root contains a large proportion of very pure white faecula, resembling the finest arrow root or starch. To procure this, the fresh root should be reduced to a pulp, and placed on a strainer. Repeated portions of cold water should then be poured on it, which in passing through the strainer carry with them the farinaceous part, leaving the fibrous portion behind. The faecula thus obtained, loses its acrimony on being thoroughly dried, and forms a very white, delicate and nutritive substance. Dr. M'Call of Georgia found these roots to yield one fourth part of their weight of pure amylaceous matter.—It is not uncommon for a nutritious faecula to exist in pungent and poisonous roots. The Laplanders prepare a wholesome bread from the acrid roots of Calla palustris, and the juice of the Cassava, or bread root tree of the West Indies, is known to be highly deleterious while recent.
[Note F.] [Linnaeus, in his Flora Laponica, tells us that the roots of Calla palustris, although acrid and caustic in the highest degree, (ignis firme instar,) are made into a kind of bread in high estimation, called Missebroed. This is performed by drying and grinding the roots, afterwards boiling and macerating them until they are deprived of acrimony, when they are baked like other farinaceous substances into bread.
The recent juice of the Jatropha manihot, or Cassava tree of the West Indies, is highly poisonous. The deleterious principle however resides in a volatile portion, which is dissipated by heat. The remaining substance of the root is used by the inhabitants for bread, as a material for a kind of soup, and as the basis of a fermented liquor.]
Linnaeus, sp. pl.
Willdenow, iv. 480.
Aiton, Hort. Kew. iii. 315.
Walter, Carol. 224.
Michaux, Fl. ii. 188.
Pursh, ii. 399.
Dracunculus s. Serpentaria triphylla, &c.
Bauhin, Pin. 195.
Arum s. Arisarum, &c.
Morison, Hist. iii. 547, s. 13, t. 5.
Plukenet, t. 77, f. 5. also t. 376, f. 3.
Schoepf, Mat. Med. 133.
Rush, ii. 301.
Barton, Coll. 29, &c.
M'Call, in Philad. Med. and Phys. Journal, ii. 84.
Thacher, Disp. 153.
Cutler, Mem. Amer. Acad. i. 487.
American Medical Botany, 1817-1821, was written by Jacob Bigelow, M. D.