Campanula glomerata Clustered Bellflower C DD N
I had only ever seen this plant on chalk grassland in Wiltshire until at Hook Moor, on the embankment of the A1M along with Knautia arvensis (Field Scabious) and Centaurea scabiosa (Greater Knapweed), I found it during a fruitless search for Orobanche reticulata (Thistle Broomrape).
This plant is quite common in central, southern England and is found mostly on the eastern side of the country as you go north. It is rare in Scotland and Wales and doesn't occur in Ireland.