Eupatorium, a large genus of Compositæ, allied to Coltsfoot (Tussilago) and Butterbur (Petasites). The species are mostly tropical and temperate American, but E. cannabinum is the common Hemp Agrimony of river-banks and marshy places, formerly reputed in domestic medicine. The roots of several American species are still so employed, notably Thorough-wort (E. perfoliatum) and E. purpureum. Their astringency gives several South American species a reputation in the treatment of wounds and snake-bites; and the Guaco, reckoned of almost universal efficacy in tropical America, is derived from the allied Mikania guaco. The roots of some are used in tanning, and others yield a variety of indigo.
(Eupatorium cannabinum).