Description: This crustose lichen occurs on hard limestones in hilly districts. It differs from the common Protoblastenia rupestris in having paler, yellowy-orange discs (to 0.7mm) that are flattened, and sunken into pits in the substrate. The green-brown to orange-grey thallus is faint. It is uncommon except in areas of naturally occurring limestone.

Key Identification Features:

• The flattened, rather pale yellow apothecia that are embedded in pits serve to distinguish this species from all other members of the genus Protoblastenia
• It is a lichen of hard limestones.

Original text submitted by Simon Davey

Distribution Map from NBN: Protoblastenia incrustans at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Protoblastenia incrustans at iNaturalist World Species Observations database.