Lecanographaceae Alyxoria ochrocheila (Opegrapha ochrocheila) Growth type crustose Chemical results: Orange pruina K+ red-purple Can be locally frequent on dry, shaded deciduous bark in mature woodland, particularly on Oak. Rare on sheltered siliceous rocks. Thin or immersed whitish-grey thallus, sometimes tinged brownish or olive-green. Lirellae with open discs, the margins and sometimes also the discs with reddish-orange pruina. Spores 3-septate, (12)14-16(-22) × 3-4.5(5) µm, perispore absent. Microscope photograph below. Similar: Opegrapha herbarum has non-pruinose lirellae, 3-septate spores with perispore.

Microscope photograph

Alyxoria ochrocheila (Opegrapha ochrocheila)
Studland, Dorset. April 2015