Psoraceae Protoblastenia incrustans Growth type crustose Chemical results: Apothecia K+ crimson Found on natural hard limestone, most frequent in upland areas Thin pale yellowish-grey thallus, often immersed with small (<0.5mm) pale yellow-orange, flat or slightly convex apothecia in deep pits in substrate. Spores 9-13 x 4-6 µm. Microscope photographs below. Similar: P. rupestris. Calcareous substrates and mortar. Larger spores

Microscope photographs



Protoblastenia incrustans
On limestone. Portland and Wool, Dorset. March 2016, 2017