A wild plant, but not very common. It is two feet high. The stalk is round, thick, jointed, and of a pale green; the knots are large. The leaves stand two at each joint; they are of an oval figure and dark green colour, smooth, not dentated at the edges, and full of large ribs. The flowers stand in a kind of clusters at the tops; they are white or reddish, and not very large; the root is knobbed and has great many fibres running from it: it is of a disagreeable mawkish taste.
The root is used; and it should be fresh taken up; a decoction of it opens obstructions, and promotes urine and perspiration. It is an excellent sweetener of the blood.