Opegraphaceae Opegrapha vulgata Chemical reactions negative. Epithecium dull chocolate-brown Common on shaded, smooth bark and smooth areas of rough-barked trees Sometimes host to Laeviomyces opegraphae Very variable. The smooth or cracked, white, grey or brownish thallus is often olive-tinged. Slender lirellae form interlocking networks, the discs usually remaining slit-like. Lirellae to 2.5 mm, curved, straight or stellate. Black pycnidia often present. Spores (4-)6(-8) septate, 20-35 x 2.5-4 µm, often curved. Conidia sickle-shaped 9-18 x 1-1.5 or bacilliform 3-5 x 1 µm. Microscope photographs below. Similar: O. niveoatra. Lirellae to 1mm. Conidia smaller, curved

Microscope photographs





Opegrapha vulgata
Dorset. December 2012, March 2013, 2016