Opegrapha hochstetteri Coppins
Opegrapha saxatilis DC
Opegrapha rupestris Pers. p.p.
No visible thallus or else endolithic and visible only by a different coloring of the substrate: greyish, dirty whitish, etc. Apothecia generally numerous in the form of isolated and scattered lirellae or else united in small groups, at first globose or very short then a little more elongated, 0.2-0.8 x 0.1-0.2 mm, sessile and as if resting on the substratum, straight or a little sinuous, never branched, with a well-opened split in the center (like a grain of wheat), black and shiny. Asci clavate, fissitunicate, 50-60 x 16-17 µm with (4) 6 (8) spores. Spores elliptical with a broader apex, 3-septate, with a small gelatinous perispore, colorless but becoming somewhat brownish and very finely warty in old age, (15) 16-19 x (4.7) 5-6 µm according to the literature; 15-21 x 5-7 µm according to our measurements. Paraphyses somewhat branched, covered with fine brownish granules, with a swollen apex. Rare species developing on the saxicolous Verrucariaceae and in particular Verrucaria hochstetteri and Verrucaria muralis..
Species recently separated from Opegrapha rupestris which comes from Bagliettoa and whose asci have 8 spores.