Species: Physcia aipolia
Photos: On deciduous twigs. Ballingeary, Cork, SW Ireland.
Whitish or pale bluish-grey thallus to 6cm diameter. Very distinct pale pseudocyphellae on lobes. Dark rhizines on under-surface. Abundant dark-brown or black, +/- pruinose apothecia. Asci are 8-spored, spores 1-septate, brown, thick-walled. 18-24 x 7-10 Ám. Microscope photographs below.
Occurs on well-lit, nutrient-rich trees, often in the nodes of twigs and branches. Cortex and medulla: K+ yellow
Parasitised by Nectriopsis physciicola.
Similar: Physcia stellaris. Medulla: K-