Symphytum officinale

Symphytum officinale is a perennial flowering plant in the family Boraginaceae. Along with thirty four other species of Symphytum, it is known as comfrey (from the Latin confervere to 'heal' or literally to 'boil together', referring to uses in ancient traditional medicine). Internal or long-term topical use of comfrey is discouraged due to its strong potential to cause liver toxicity. To differentiate it from other members of the genus Symphytum, this species is known as common comfrey or true comfrey. Other English names include boneset, knitbone, consound, and slippery-root. It is native to Europe, growing in damp, grassy places. It is found throughout Ireland and Britain on river banks and ditches. It occurs in North America as an introduced species and weed. The flowers are mostly visited by bumblebees....read more on Wikipedia.