Arum.—The root or corm of Arum maculatum L. (Fam. Araceae), is occasionally used as a medicine in Europe. Its properties closely resemble those of Arisaema triphyllum. Its constituents, according to Enz, are a neutral acrid volatile principle soluble in ether, starch, gum, mucilage, sugar, lignin, albumen, saponin, fixed oil, resin, and calcium phosphate, the fresh corm containing 58.4 per cent. of water, 5.2 of lignin, and 27.2 of starch. (A. J. P., xxxi.)
Arisaema triphyllum (L.) Schott. Gouet a trois feuilles, Fr. Dreiblättriger Aron, G. (Fam. Araceae.) Dragon-root, Pepper Turnip, Indian Turnip, Jack-in-the-pulpit, Wake-robin.—This plant is common in all parts of the United States, growing in moist shady places. The corm was formerly official. It is roundish, flattened, an inch or two in diameter, covered with a brown, loose, wrinkled epidermis, and internally white, fleshy, and solid. In the recent state it has a peculiar odor, and is violently acrid. It was found by D. S. Jones to contain, besides the acrid principle and from 10 to 17 per cent. of starch, albumen, gum, sugar, extractive, lignin, and salts of potassium and calcium. (A. J. P., xv, 83.) The acridity has been ascribed to the raphides of calcium oxalate by R. A. Weber (J. Am. C. S., 1891, p. 215). This has been denied, Schneegans proving that A. maculatum contains saponin and Spica and Biscaro ascribe the acridity to the same principle. (Ph. Centralh., 1895, p. 731.) The Indian turnip may be preserved fresh for a year, if buried in sand.
From both Arum maculatum, L., and Arum italicum Mill., Herbert and Heim (P. J., July 31, 1897) separated a saponin, also a brownish, oily, liquid alkaloid closely resembling coniine in its properties, but less active. They also found a saponin in the arum tubers.
Both the European and American arum are, in their fresh state, violent irritants to the mucous membranes, producing when chewed insupportable burning in the mouth and throat. Taken internally, this plant causes violent gastro-enteritis, which may end in death. The fresh, partially dried root has been used internally as a stimulant to the secretions, especially in asthma, whooping cough, chronic catarrh, and rheumatism. Dose, ten grains (0.65 Gm.), two or three times a day, increased to half a drachm (2 Gm.). The perfectly fresh root should not be used, and the fully dried root is inactive.
The corm of the European arum contains much starch, and a farina is prepared from it, in small quantities, in the Isle of Portland, on the south coast of England, and called Portland arrow root, or Portland sago. The root of A. esculentum, L. (more correctly Colocasia antiquorum Schott.), which abounds in starch, is much used by the natives of the Hawaiian and other islands of the Pacific as an article of food, having been previously deprived of its acridity by heat.