Comfrey [Symphytum officinale]
Also known as Knitbone, Knitback, Blackwort, Bruisewort, Yalluc, Boneset. Historically known to treat a wide variety of complaints including broken bones, burns & skin conditions. Used also as a fertiliser in organic gardening as it is deep-rooted and stores in its leaves a host of nutrients.
It is mildly astringent and has been used for lung complaints and whooping cough. As an external remedy the leaves are wrapped around sprains, swellings & bruises. Comfrey root mixed with Chicory & Dandelion root were used to make a type of coffee. Culpepper recommended it for grout.