Order: Pertusariales Family: Pertusariaceae
Species: Pertusaria lactea
Photos: On upland rock. Caha Pass, Co. Cork, SW Ireland.
Thick, smooth or areolate, whitish to pale grey thallus with a white prothallus. Delimited whitish soralia are scattered over the thallus but the white-pruinose, pinkish apothecia are rare.
Occurs on damp, well-lit, siliceous or slightly calcareous rocks in upland and coastal areas.
K-, thallus, soralia C+ reddish-pink, KC+ red, UV +/- faint blue-white
Similar: P. aspergilla. K +/- brownish red, C-, KC+ yellow-red
Pertusaria lactea January 2012