Order: Pertusariales       Family: Megasporaceae Circinaria contorta (Aspicilia contorta subsp. contorta) Growth type crustose. On concrete fences. Co. Cork, SW Ireland Greenish-grey thallus with separate, convex areoles that later merge and become paler in colour. Prothallus indistinct. Apothecia are immersed black discs, often covered with bluish-white pruina, usually single in centre of each areole. Asci are 4-spored, spores simple, 20 x 11 µm. Epithecium olive-green, K+ orange-yellow. Chemical reactions negative. Common on concrete, mortar and hard calcareous rocks, very tolerant of nutrient enrichment. Previously two sub-species recognised, subsp. contorta and subsp. hoffmanniana but molecular data (2016) indicates they are two species: Circinaria contorta and Circinaria hoffmanniana Similar: Aspicilia calcarea

Circinaria contorta (Aspicilia contorta subsp. contorta). On concrete, Co. Cork. December 2011 and January 2012