What is "symphytum asperrimum"

Comfrey \Com"frey\, n. [Prob. from F. conferve, L. conferva, fr. confervere to boil together, in medical language, to heal, grow together. So called on account of its healing power, for which reason it was also called consolid

1. ] (Bot.) A rough, hairy, perennial plant of several species, of the genus Symphytum.

   Note: A decoction of the mucilaginous root of the ``common comfrey'' ( Symphytum officinale) is used in cough mixtures, etc.; and the gigantic ``prickly comfrey'' ( Symphytum asperrimum) is somewhat cultivated as a forage plant.