ACORUS, CALAMUS AROMATICUS, SWEET FLAG, or SWEET RUSH; a genus of the monogynia order, belonging
longing to the hexandria class of plants, of which only one species is known. It grows naturally in shallow standing waters, and is found wild in some parts of Britain. The leaves are sometimes two feet long, narrow, compressed, smooth, and of a bright green, terminating in a point; the root is pretty long, of a whitish, reddish, and partly greenish colour. Among the leaves there arises a single one, thicker and more robust than the rest, furrowed on the surface, and of a paler green. On this grow frequently two spikes of flowers, by many writers called juli. These are of a brown colour, having a chequered surface. The root of this plant has a very agreeable flavour, which is greatly improved by drying. It is reckoned carminative and stomachic, having a warm, pungent, bitterish taste; so is frequently used as an ingredient in bitters*. It has been complained of, however, as communicating a nauseous flavour to those bitters in which it was infused; and Neumann observes, that its agreeable flavour, as well as its distinguishing taste, reside entirely in a volatile essential oil; the residuum after distillation having a nauseous flavour, not at all resembling that of the calamus.—The Turks candy the roots, and imagine them a preservative against contagion. They are usually imported from the Levant into Britain; though those of our own country might answer equally well. Neither horses, cows, goats, sheep, or swine, will eat the herb, or its roots.
Culture. The acorus being a perennial plant, may be transplanted into a garden, where it will thrive very well if the ground is moist; but never flowers unless it grows in water. It loves an open situation, and will not thrive well under the shade of trees. The flowers appear the latter end of June, and continue till August.