Synonyms---Horseweed. Richweed. Richleaf. Knob-Root. Knobweed. Horsebalm. Hardback. Heal-all. Oxbalm. Knot-Root. Baume de Cheval. Guérit-tout.
---Parts Used---Whole plant, fresh root.
---Habitat---North America, from Canada to the Carolinas.
---Description---The plant has a four-sided stem, from 1 to 4 feet in height, and bears large, greenish-yellow flowers. It grows in moist woods and flowers from July to September. The rhizome is brown-grey, about 4 inches long, knobby, and very hard. The whole plant has a strong, disagreeable odor and a pungent and spicy taste. The chief virtue of the plant is in the root, which should always be used fresh. The name is derived from its discoverer, Peter Collinson.
---Constituents---In the root there is resin, starch, mucilage and wax. In the leaves, resin, tannin, wax and volatile oil. The alkaloid discovered in the root appears to be a magnesium salt.
---Medicinal Action and Uses---Sedative, antispasmodic, astringent, tonic, diaphoretic, diuretic.
A decoction of the fresh root has been given in catarrh of the bladder, leucorrhcea, gravel and dropsy. It is largely used by American veterinary surgeons as a diuretic. It is valuable in all complaints of urinary organs and rectum, and is best combined with other drugs.
It can be used externally, especially the leaves, for poultices and fomentations, bruises, wounds, sores, cuts, etc., and also as a gargle, in the strength of 1 part of fluid extract to 3 of water.
---Preparations and Dosages---Of fluid extract, 15 to 60 drops. Of Collinsonin, 2 to 4 grains.