My mistake was to think these two are the same plant.

The first one I am told is the butterbur, Petasites hybridus, a native plant that grows in damp places.

This one, part of a group, is growing by the stream in Mundesley.

The second one is Petasites fragrans and is growing on the cliff.

Its common name is Winter Heliotrope and it is from North Africa. The flowers are similar but, as you can see, not quite the same. The heliotrope has some leaves when flowering while the butterbur does not. Neither plant is that common so finding both of them on my patch is rather exciting.