A common wild plant that grows undistinguished among the flags and rushes, by our ditch sides. The old physicians meant another thing by calamus aromaticus: they gave this name to the dried stalks of a plant, but at present it is used as the name of the root of this. The sweet flag grows three feet high, but consists only of leaves without a stalk. They are long, narrow, and of a pale green colour. Among these there are commonly three or four in all respects like the rest, but that they have a cluster of flowers breaking out at one side, within five or six inches of the top. This is long, brown, and thick, and resembles a catkin of a filbert tree, only it is longer and thicker. The root is long, flattish, and creeping: it is of a strong and rather unpleasant smell when fresh, but it becomes very fragrant, and aromatic in drying. Our own has its value, because we can have it fresh, but the dried root is better had of the druggists; they have it from warmer countries, where it is more fragrant.
The juice of the fresh root of acorus is excellent to promote the menses, it works by urine moderately, and gives no offence to the stomach, The dried root is cordial and sudorific, it warms the stomach, and is good against indigestions and fevers.