ETTPATORIUM, a genus of plants of the natural order compositce, sub-order corymbi ferce, having small flowers (heads of flowers) in corymbs, florets all tubular and hermaphrodite, club-shaped stigmas, imbricated bracts, a naked receptacle, and a hairy pappus. The species are numerous, and mostly American. One only is British, the common ACRIMONY (E. eanmabinum), a slightly aromatic perennial plant, grow ing mostly in marshy places, and on the banks of streams. The root was formerly employed as a purgative, and the plant was also used as a diuretic and as a vulnerary. —Tuonouon-woler (E. perfoliatunt), a species having-the opposite leaves joined at the base, is very common in low grtainds in North America, and is a pOpular medicine, much esteemed and used in that country. It is often administered in intermittent fevers. It acts powerfully as a sudorific, and is often very beneficial in catarrh and influenza. It is also emetic and purgative, and, in small doses, tonic. The whole
plant is very bitter.—Other North American species possess similar properties, and the root of one, known as GRAVEL-ROOT (E. purpureum), is employed as a diuretic for relief of the disease from which it derives its name.—The AYAPANA (E. ayapana), a half shrubby species, native of the n. of Brazil, has a high reputation in that country as a cure for snake-bites, and has been introduced into the East Indies. It is a very power ful sudorific, and is also diuretic.—The famous Peruvian vulnerary, MATICO, has been referred, but uncertainly, to a shrubby species of this genus, E. glutinosum.—GuAco or HTJACO, much valued in Peru as a cure for snake-bites, is supposed to belong to the allied genus mikania.