Description: This ‘bark pimple’ species with an immersed thallus and spherical discs (perithecia) can be distinguished in the field by the glazed-over appearance of the discs caused by a thin cover of bark cells. Under the microscope the one-septate spores (14.5-22&

371;m long) are doubly constricted, giving the spore a twin-hourglass appearance. It grows chiefly on smooth bark, especially ash. Scattered but rare in east and midland Ireland.

Key Identification Features:

• The small discs appear frosted; spores one-septate and doubly constricted
• Only confused with A. analepta which lacks the disc frosting and doubly constricted spores and has larger discs.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Alloarthopyrenia italica at iNaturalist World Species Observations database.