Order: Pertusariales       Family: Pertusariaceae Species: Pertusaria hemisphaerica Growth type crustose. Photos: On Chestnut trunk. Macroom, Co. Cork, SW Ireland. Identification confirmed by B. Coppins. Thallus whitish or pale bluish-grey, smooth or warted with distinct zoned white prothallus. Conspicuous convex soralia, often becoming confluent. Soredia granular, pale bluish-grey or concolorous with thallus. Apothecia are unknown. On well-lit or slightly shaded, mature, rough-barked trees, often near base of trunk. Rare on rock. Soralia K-, C+ carmine-red, KC+ red, P-, UV+/- glaucous Similar: Loxospora elatina. Damp, acid bark, K+ yellow. Ochrolechia androgyna. Yellow soredia, C+ red, KC+ orange-red.

Pertusaria hemisphaerica February 2010