Please ID my mystery plant
I found this in one of my borders this morning ... I don't recognise it and don't remember planting it ... although I've had some helpers doing stuff in the garden while I was laid up, I don't think anyone planted anything I didn't know about.
I really don't have a clue what this is ... any ideas?
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.