Lichen?

Lichen?

Observation - Lichen? - UK and Ireland. Description: Thought I would do the Opal Air survey, but even after reading and looking at all the pictures on the website I am not sure what I'm looking at! Help please! North facing side of garden seat.

Thought I would do the Opal Air survey, but even after reading and looking at all the pictures on the website I am not sure what I'm looking at! Help please!

North facing side of garden seat.