Symphytum asperum is a flowering plant of the genus Symphytum in the family Boraginaceae. Common names include rough comfrey and prickly comfrey. It is the tallest Symphytum species.[1] It is native to Asia, and it is known in Europe and North America as an introduced species and sometimes a weed. Symphytum × uplandicum, the naturally occurring hybrid with the common comfrey (Symphytum officinale), is the economically most important kind of comfrey.