Unknown lichen sp.

Unknown lichen sp.

Observation - Unknown lichen sp. - UK and Ireland. Description: Plenty of this growing on large sea defence boulders but not sure if the main subject in the photo is one or more lichens - any comments will be great - thanks. Approx 20mm in diameter.

Plenty of this growing on large sea defence boulders but not sure if the main subject in the photo is one or more lichens - any comments will be great - thanks. Approx 20mm in diameter.