Order: Lecanorales       Family: Physciaceae Species: Physcia caesia Growth type foliose. Photos: On rocks and wooden bench. Co. Cork, SW Ireland. Adpressed, orbicular, pale bluish-grey thallus, convex lobes with small pseudocyphellae. Underside white to tan with scattered rhizines. Abundant farinose or globular soralia with bluish-grey flecks. Black, pruinose apothecia with prominent margins. Usually found on nutrient-rich rocks, tombstones, cement and asphalt but can also occur on basic-barked trees. Cortex and medulla: K+ yellow Similar: Physcia dubia has narrower lobes with terminal soralia. Rare in Ireland, on siliceous rocks and walls. Medulla K-

Physcia caesia. December 2008 and May 2012