Eupatorium perfoliatum, known as common boneset or just boneset, is a North American perennial plant in the aster family. It is a common native to the Eastern United States and Canada, widespread from Nova Scotia to Florida, west as far as Texas, Nebraska, the Dakotas, and Manitoba. It is also called agueweed, feverwort, or sweating-plant. It was introduced to American colonists by natives who used the plant for breaking fevers by means of heavy sweating. It is nearly always found in low, wet areas.
Eupatorium perfoliatum grows up to 100 cm (39 inches) tall, with leaves that clasp the stems. The plant produces dense clusters of tiny white flower heads held above the foliage.
E. perfoliatum leaves and roots contain mixed phytochemicals, including polysaccharides (containing xylose and glucuronic acid), tannins, volatile oil, sesquiterpene lactones, sterols, triterpenes, alkaloids, and various flavonoids, such as quercetin, kaempferol, and caffeic acid derivatives.E. perfoliatum and several of its related species are listed on the Poisonous Plants Database of the US Food and Drug Administration, with E. perfoliatum described as an "unapproved homeopathic medicine" with unknown safety by the US National Library of Medicine.
Eupatorium perfoliatum (also called boneset) was used in traditional medicine by Native Americans who applied extracts for fever and common colds. Possible effects of E. perfoliatum for these uses remain undefined by adequate scientific research, and are unconfirmed by high-quality clinical research. If consumed in large amounts, its tea made from leaves may cause diarrhea.
Eupatorium perfoliatum is a specific butterfly food and habitat plant. It provides nectar for butterflies in the adult life cycle stage, particularly the white M hairstreak and the bronze copper butterfly.