Lecanographaceae Alyxoria xerica (Opegrapha xerica) Chemical results negative. Epithecium brownish in water, K+ olive-green Found on dry acidic bark, particularly of mature and old Oaks and Yews, and spreading onto nearby Ivy and dead bramble stems. Sometimes host to Milospium graphideorum Thin grey or greenish thallus with (usually) simple lirellae. Disc slit-like becoming +/- expanded, sometimes pruinose. Spores are 3-5 septate, sometimes with a larger middle cell, 14-20 x 4-5.5 µm. Microscope photographs below. Similar: O. varia. Epithecium brown, K-. Larger spores, 4-6 septate

Microscope photographs





Alyxoria xerica (Opegrapha xerica)
Lytchett Minster and Puddletown, Dorset. December 2016, May 2017