Opegrapha vulgata forma
Opegrapha cinerea Chevall. ?
This form is distinguished by its thallus greenish-gray. It grows on the more or less smooth bark of deciduous trees (here Ulmus) of oceanic forests. Spores 5-7 (8) septate, 22-28 x 3-4 µm according to our measurements. Sickle pycnidiospores: 10-15 x 1 µm according to our measurements.