Cream-coloured coastal lichen

Cream-coloured coastal lichen

Observation - Cream-coloured coastal lichen - UK and Ireland. Description: Large area on vertical surface of south-facing siliceous rocks, near high water mark, covered with (I think) Caloplaca marina and a cream-coloured crustose lichen. Cream-coloured lichen has lecanorine apothecia with blackish discs. Chemical tests: C-,K-.

Large area on vertical surface of south-facing siliceous rocks, near high water mark, covered with (I think) Caloplaca marina and a cream-coloured crustose lichen. Cream-coloured lichen has lecanorine apothecia with blackish discs. Chemical tests: C-,K-. Weather had been sunny showers all day before pictures i and ii. Image iii after wetting lichen with freshwater from cliff stream. Image iv taken about 20 minutes later. Possibly Lecanora actophila.