Physciaceae Rinodina oleae (Rinodina gennarii) Growth type crustose Chemical results: Thallus K-. Hymenium K+ blue Pollution tolerant, common on basic or nutrient-rich rocks, walls, concrete, bark and wood. Greyish or grey-green thallus, sometimes +/- absent. Abundant apothecia, discs brown-black with thick margins that become excluded with age. Spores brown, 1-septate, (11-)13-17(-21) x (6-)7-10 µm. Micrograph below. Sometimes host to Muellerella pygmaea Similar: Rinodina roboris. K+ yellow, occurs on well-lit bark. Lecania erysibe has narrower, colourless spores.

Microscope photograph

Rinodina oleae
On timber. Brands Bay, Dorset. January 2013