Common Acorus, or Yellow Flags.
A common plant in our ditches, and by river sides, distinguished by its blue-green flag like leaves, and its large yellow flowers, which in shape resemble those of the iris, or flower de luce. It grows four feet high: the stalk is roundish, but a little flatted, of a pale green, very erect, firm, and not branched. It only sends out two or three shoots upwards from the bosom of the leaves. The leaves are a foot and a half long, narrow, flat, and sharp at the edges; the flowers stand at the tops of the stalks, and are large and beautiful. The seeds are numerous, and are contained in large triangular vessels. The root creeps.
The root of this is the only part used; some have confounded them with the true acorus root, but they are called, by way of distinction, false or bastard acorus; they are not at all like them in shape, colour, or qualities; they are of a reddish brown, have no smell, and are of an austere taste; they are an excellent astringent. They should be taken up in spring and dried, and afterwards given in powder. They stop fluxes and overflowings of the menses.