Order: Pertusariales       Family: Pertusariaceae Varicellaria hemisphaerica (Pertusaria hemisphaerica) Growth type crustose. Identification confirmed by B. Coppins. Photos: On Chestnut trunk. Macroom, Co. Cork, SW Ireland. 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. Dark patch in centre of thallus is possibly the superficial mycelium of the lichenicolous hyphomycete Sphaerellothecium araneosum. 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.

Varicellaria hemisphaerica (Pertusaria hemisphaerica) February 2010