Comfrey (Symphytum officinale) and boneset (Eupatorium perfoliatum) are different plants, although both have been used historically to treat ailments. Comfrey originated in Asia and Europe, and boneset is native to North America. The perennial shrub comfrey is sometimes called boneset or knitbone since it was used medicinally to treat broken bones. Meanwhile, Native Americans used boneset to break fevers and relieve pain.