I've had this in my garden for a few years, keeps popping up, and had assumed it was comfrey, but further checking today suggests otherwise.
The flowers appear very similar to a white comfrey, but the leaves are not nearly so lanceolate as comfrey, and seem more to resemble borage leaves. The overall structure of the plant appears to be borage family, but I've looked right through my Rose and Fitter/Fitter/Blamey books but can't find a match.
The flowers appear very similar to a white comfrey, but the leaves are not nearly so lanceolate as comfrey, and seem more to resemble borage leaves. The overall structure of the plant appears to be borage family, but I've looked right through my Rose and Fitter/Fitter/Blamey books but can't find a match.