Order: Lecanorales       Family: Bacidiaceae Species: Tephromela atra Growth type crustose. Photos: On coastal rock. Ballyrisode, Cork, SW Ireland. Thick, warted-areolate, whitish or pale grey thallus with blackish prothallus. Variable black apothecia, round or irregular, sessile or immersed. Discs flat / concave, margins swollen, entire or flexose. Hymenium dark purple-brown or purple-violet, upper pale purple-violet. Common on coasts and inland on siliceous or slightly basic rocks and walls. Tephromela atra var. torulosa is occasionally found on trees. Cortex K+ yellow, C-, KC+ yellow. Medulla UV+ ice-white. Apothecia purplish in section. Similar: Lecanora gangaleoides

     



Black Shields, Tephromela atra. Ballyrisode, Co.Cork. January 2009