Brown lichen

Brown lichen

Observation - Brown lichen . Description: Lichen with brown areolate thallus growing in extensive patches on the quartz sandstone coping-stones on the brick walls of a bridge (third picture). Black lecideine apothecia with pruinose discs and pruinose margins. Whitish-cream patches (possibly sor

Lichen with brown areolate thallus growing in extensive patches on the quartz sandstone coping-stones on the brick walls of a bridge (third picture). Black lecideine apothecia with pruinose discs and pruinose margins. Whitish-cream patches (possibly soredia) on edges of some areoles (especially first picture and right hand side of second picture). Seems unlikely but possibly Porpidia melinodes.