Urtica. Stinging nettles. Urtica dioica, Urtica urens.
Urtica. Ortie brulante, Fr. Brennessel, G.—Various species of this genus (Fam. Urticaceae) are furnished with poisonous stinging hairs. Urtica gigas A. Cunn. (now Laportea gigas Wedd.), of Eastern Australia is said frequently to kill horses, and to produce in man a sting whose impression lasts for months. (N. R., 1875.) It has generally been thought that the virulence of the hairs is due to the presence of free formic acid (A. J. P., xxii), and David Hooper (P. J., April, 1887) has demonstrated the presence of formic acid, or a substance very closely allied to it, in the hairs of the Nilgiri nettle (Girardinia palmata Gaudich.). Nevertheless, it does not seem probable that formic acid is the poison. G. Haberlandt believes it to be a non-volatile albuminoid, and L. Renter has obtained from several nettles a glucoside. (A. J. P., Jan., 1890.) Oddi and Lomonaco (Rif. Med., April, 1892) isolated from the common nettle a crystalline alkaloid, and found that in mammals the extract acts powerfully upon the vasomotor system, and in frogs causes centric paralysis with diastolic cardiac arrest.
U. dioica L., or common nettle, and U. urens L., or dwarf nettle, European plants naturalized in waste places to some extent in the United States, have been used in medicine as local irritants, as diuretics (A. J. P., 1866), and especially for the purpose of arresting uterine hemorrhage. The fluidextract may be given in doses of half a fluidrachm (1.8 mils) or a decoction of the strength of an ounce to a pint in teacupful doses. Under the name of brandol is marketed a preparation used in the treatment of burns and wounds; it is a liquid consisting of 93 per cent. infusion of urtica, 2 per cent. picric acid and 5 per cent. glycerin.