Species: Leptogium brebissonii
Photos: On Oak and Salix. Glengarrif woods, Cork, SW Ireland.
Specimen below identified by Mike Simms
Rounded lobes are much swollen when wet, green-black to brownish-black, dark-grey, flattened and ridged when dry. The brownish isidia are coralloid or flattened, apothecia are absent. Lower surface is not tomentose.
West of Ireland on mossy rocks and damp, deciduous trees.
Chemical reactions negative.
Similar: Leptogium coralloideum
Leptogium brebissonii May and December 2009