Arum Triphyllum. Dragonroot.
Nat. Ord. — Araceae. Sex. Syst. — Monoecia Polyandria.
Cormus or Root.
Description. — Arum Triphyllum (Arisaema Triphylla) is variously called Wake Robin, Indian Turnip, Jack-in-the-pulpit, etc. It has a round, flattened, perennial root or cormus, the upper part of which is tunicated like the onion, and the lower and larger portion tuberous and fleshy, giving off numerous, long white radicles in a circle, from its upper edge ; the under side is covered with a dark, loose, wrinkled epidermis. Early in the spring a large spathe grows up, which is ovate, acuminate, convoluted into a tube at the bottom, flattened and bent over at the top like a hood, varying in color internally, being green, dark-purple, black, or variegated, with pale-greenish stripes on a dark ground, and supported by an erect, round, green, purple, or variegated scape, invested at the base by the petioles and their acute sheaths. Within the spathe is a club-shaped spadix, shorter than the spathe, rounded at the end, green, purple, black, or variegated, contracted into a narrow neck at the base, where it is surrounded by the stamens or germs. In the fertile plants, it is invested with roundish crowded ovaries each tipped with a stigma; in the barren, its base is covered with conical, fleshy filaments, each bearing from two to four circular anthers. Plants which are perfectly monoecious, and which are the least common, have stamens below the ovaries. The upper portion of the spadix gradually decays, together with the spathe, while the ovaries are converted into a large compact bunch of shining, scarlet berries. The leaves are usually one or two in number, standing on long sheathing footstalks, ternate ; the leaflets oval, mostly entire, acuminate, smooth, paler on the under-side, becoming glaucous as the plant grows, and the two lateral ones somewhat rhomboidal.
History. — This plant is common to North and South America, growing in all moist and damp situations, and flowering from May to July.
The whole plant is acrid, but the root is the only part employed ; it is about an inch or two in diameter, turnip-shaped, dark externally, and white, fleshy, and solid internally. When fresh, it is very acrid, causing when chewed, an intense burning and biting sensation in the mouth and fauces, which is persistent, and leaves a subsequent soreness; milk relieves this sensation, considerably modifying its intensity. It exerts no such influence upon the external skin except upon long and continued application. The acrid principle is highly volatile, is not taken up by water, alcohol, the acids, or oil, and is wholly dissipated by heat. It becomes inert by age, and should always be used in the recent state, or when but partially dried ; if buried in sand, its activity may be preserved for twelve or fifteen months. In addition to its acrid principle, it contains albumen, gum, sugar, starch, extractive lignin, and salts of potassa and lime. A very white, delicate and nutritive amylaceous substance can be prepared from it, resembling the finest arrowroot. It is too acrid for use when taken immediately from the ground.
Properties and Uses. — Acrid, expectorant, and diaphoretic. Recommended in flatulence, asthma, pertussis, chronic catarrh, chronic rheumatism, bronchitis, pains in the chest, aphthous sore-mouth, colic, low stage of typhus, and various affections connected with a cachectic state of the system. Externally it has been used in scrofulous tumors, tinea capitis, and other cutaneous diseases. Dose, of the powder, ten grains two or three times a day, gradually increased ; it may be taken in syrup, honey, or gum arabic emulsion.
Off. Prep. — Emplastrum Picis Compositum.