Order: Lecanorales Family: Physciaceae
Species: Rinodina oleae (R. gennarii)
Photos: On estuary post. Co.Waterford, Ireland.
Greyish or grey-green thallus, sometimes +/- absent. Abundant apothecia, discs brown-black with thick margins. Spores brown, 1-septate, 13-16 x 7-10 Ám. Microscope photographs below.
Pollution tolerant, common on basic or nutrient-rich rocks, walls, concrete, bark and wood.
Similar: Rinodina roboris is K+ yellow, occurs on well-lit bark.
Lecania erysibe has narrower, colourless spores.