Boneset

Boneset, Eupatorium perfoliatum, is a hairy stemmed, perfoliate native perennial. It's name conjures up magical properties of healing broken bones but as we'll read below that's just a bit off.

From A Manual of Weeds:

A near relative of Joe-Pye Weed, and also used in medicine, the parts desired being the flowering tops, gathered when in full bloom, and the leaves, stripped from the stalks and quickly dried, for which collectors receive three to eight cents a pound.

From Wikipedia:

Boneset, although poisonous to humans and grazing livestock, has been used in folk medicine^[4], for instance to excrete excess uric acid which causes gout. Eupatorium has many more presumed beneficial uses, including treatment of dengue fever, arthritis, certain infectious diseases, migraine, intestinal worms, malaria, and diarrhoea. Boneset infusions are also considered an excellent remedy for influenza. Scientific research of these applications is rudimentary at present, however.

Caution is advised when using boneset, since it contains toxic compounds that can cause liver damage. Side effects include muscular tremors, weakness, and constipation; overdoses may be deadly.

Georgia, Ada E. A Manual of Weeds. NewYork, 1914. 417. Web. Google Book Search. 28 Sep 2009.

"Eupatorium." Wikipedia, The Free Encyclopedia. 3 Sep 2009, 19:44 UTC. 3 Sep 2009 <http://en.wikipedia.org/w/index.php?title=Eupatorium&oldid=311711328>.