Teloschistaceae Athallia pyracea (Caloplaca pyracea) Growth type crustose. Chemical results: Apothecia K+ red Usually on Aspen, but also on twigs and small branches of other trees The thin and sometimes poorly evident thallus is pale grey to whitish and forms patches 0.5-2cm wide. Apothecia are scattered to crowded, orange to yellow-orange and flat or slightly convex. The proper margin is usually slightly paler than disc, thalline margin greyish to yellow-grey. Asci 8-spored, spores polarilocular, (8.5-)10-14(-15.5) x (4.5-)6-9(-10) µm, septum (3-)4-5.5(-7.5) µm, c1/3-1/2 spore length. Micrographs below. Separated from Athallia holocarpa agg. (Caloplaca holocarpa aggregate)

Micrographs



Athallia pyracea (Caloplaca pyracea)
Photographs: Broadstone and Randalls Hill, Dorset. April 2025, October 2025