Caliciaceae Diploicia canescens Growth type placodioid (crustose with lobed margins). Chemical tests: K+ yellow, C-, KC+ yellow, P-, UV- or UV+ orange Occurs on both basic and nutrient-rich walls, rocks, headstones and trees. White or pale bluish-grey thallus with white-pruinose marginal lobes. Centre covered with patches of yellowish soralia becoming eroded with age. Apothecia more frequent in coastal areas, pycnidia sometimes on lobes of fertile specimens. Spores brown, 1-septate, 10-15 x 5-8 µm. Microscope photograph below. Occasionally host to Arthonia diploiciae # Similar: Solenopsora candicans. Usually fertile, K-, P+ orange

Microscope photograph

Diploicia canescens
Studland and Kimmeridge churchyards and Holton Lee, Dorset. October 2012 and January 2013