Caloplaca cerina. A species that has suffered some decline due to Dutch Elm Disease. It occurs fairly frequently on hazel branches and other shrubs. This photograph was taken on an upright post in the estuary at Littlehampton on which it occurred with Caloplaca marina. It is unusual in this photograph in having a relatively thick, pale grey thallus. It is more usual to have an almost invisible thallus with scattered apothecia on the substrate. Unfortunately the posts at Littlehampton are no longer there.