Order: Lecanorales       Family: Ramalinaceae Species: Bacidina caligans (Bacidia caligans) Growth type crustose Photos: On mortared wall, Coachford, Co. Cork, SW Ireland. Identified by John Douglass Pale green, grey or brownish finely sorediate thallus with discrete soralia and small red-brown or blackish apothecia. Margins often darker or excluded. Spores are 3-7 septate, 24-48(-63) x 1.5-2(2.5)µm. Pycnidia immersed, conidia curved 29-35 x 1µm. Microscope photograph below. Thallus reactions negative but hymenium K+ purple Usually on sheltered calcareous rocks, mortar and cement, less frequent on bark and rabbit droppings

Microscope photograph

Bacidia caligans. April 2012