Symphytum caucasicum Caucasian Comfrey I
Stace describes this introduction from the Caucasus as often not persisting but at this site it has been present for thirty years to my knowledge. It is the same colour as the Pentaglottis sempervirens (Green Alkanet) which grows nearby so it is easy to miss.
There isn't very much of this plant in the British Isles but it is dotted here and there in England and Wales with just two sites in Scotland and none in Ireland.
Cwm, Near Dyserth, North Wales 7th May 2007
Added on 9th May 2007, updated 12th February 2012, updated 15th Nov 2014