Botanical Source.—Cattail flag is a perennial plant, with a smooth, round stem, 3 to 5 feet high, leafy below, and terminated by large cylindric spikes. The leaves are flat, erect, ensiform, slightly concave within near the base, 2 to 4 feet long, and nearly 1 inch wide. Flowers very numerous. Spikes of a brownish color, 6 to 10 inches in length, and about 1 inch in diameter, composed of slender, downy flowers, so compact, particularly the fertile ones, as to be of considerable hardness. The upper portion is smaller, and composed of the sterile flowers, so that the staminate and pistillate parts of the spike approximate, or, are almost continuous (W.—G.).
History.—This plant is common to all parts of the United States, and is found growing in ditches, muddy pools, borders of ponds, and other wet places, flowering in July. The leaves are called flags, and are used for weaving the seats of chairs. The flowers have been used for making beds. The root is the part used. It yields its properties to water. The Pah-Ute Indians used the flowering ends of the plant as a food, either raw, or boiled in water (Edward Palmer, Amer. Jour. Pharm., 1878, p. 547).
Action, Medical Uses, and Dosage.—Astringent and emollient. Boiled with milk, it has been found useful in dysentery, diarrhoea, and infantile summer complaint, and a decoction of it has been beneficial in gonorrhoea. Externally, the root, in combination with elm and aromatics, forms an excellent poultice for white swellings, tumors, and ulcers. The root, bruised until it becomes like a jelly, forms an excellent application for burns and scalds, erysipelas, ophthalmia, and all local inflammations.
King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.