Hidcote Blue Comfrey

Hidcote Blue Comfrey

Observation - Hidcote Blue Comfrey - UK and Ireland. Description: It's a comfrey. I am a beginner and they are tricky. These ones or their progenitors have probably m

It's a comfrey. I am a beginner and they are tricky. These ones or their progenitors have probably made good their escape from a farmhouse garden somewhere in the vicinity but they seemed to be "wild" in the sense of not having been planted or seeded here by humans, and were standing their ground against nettles, cleavers, ivy etc.
.
Being a beginner, I'm overly impressed by the flowers rather than the precise nature of the hairiness of the leaves and stems. I know this is an error. However, as you can see, the flower buds were a nice vivid scarlet, out of which emerged (to me) rather surprising flowers, sky-blue to the point of expansion of the corolla and then white. You can see from the photos that the sepals are rather blunt and very hirsute. The leaves were rough to the touch, but then it's a comfrey...
.
The nearest match in Collins' Wild Flower Guide is the Rough Comfrey, Symphytum asperum, but that doesn't look right. Googling comfreys, I came across the so-called Hidcote Comfrey, Symphytum x hidcotense. Might it be that?