This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Arsmart: an annual plant with oblong uncut leaves pointed at both ends, and imperfect flowers set in spikes on the tops of the stalks: the cup is thick and fleshy, divided into five oval segments, which, closing, form a cover to an angular glossy seed.
I. Persicaria mitis: Persicaria mitis macu-lofa C. B, Pharm. Paris. Plumbago. Polygonum Perficaria Linn. Spotted arfmart; so called from most of the leaves having a blackish spot in the middle. It grows wild in moist watery places, and flowers in July.
This plant is said to be a good vulnerary and antiseptic; and decoctions of it in wine, to restrain the progress of gangrenes (a). It has a slightly acerb taste inclining to acidity, and no remarkable smell.
2. Persicaria urens five hydropiper C. B. Polygonum Hydropiper Linn. Biting arfmart, lakeweed, water pepper: distinguished from the former by the spikes of flowers being slenderer, the leaves shorter, narrower, and without any spots; but more remarkably by its taste. In our markets, a plant of a different genus, the second of the ranunculi hereafter described, is sometimes sold for it.
The leaves of this species have an acrid burning taste, and seem to be nearly of the same nature with those of arum; their acrimony not rising in distillation, and being destroyed in the procefs (b). They are commended as antiseptic, aperient, diuretic; in scurvies and cachexies, humoural asthmas, hypochondriacal and nephritic complaints, and in the wandering gout. The fresh leaves have been sometimes applied externally, in stimulating cataplasms, and for cleansing foul ulcers and consuming fungous flesh; in which last intention they are said to be used by the farriers.
(a) Tournefort, Memoires de l'acad. des scienc. de Paris, four l'ann. 1703.
(b) Rutty, Synopsis of mineral waters, p. 524. Dr. Cullen however says, "its acrimony operates chiefly on the "kidneys. What is remarkable, it gives out its diuretic " virtue in distillation to water." Mat. Med. 308.