Alyxoria subelevata
Thallus thin or rather thick, sometimes immersed, smooth to finely rimose-cracked and ± granular, ash- to yellow-grey. Isidia and soredia absent. Photobiont Trentepohlia.
Anamorph: conidiomata pycnidia. Conidia 4-6 × 0.7-1 μm, bacilliform or slightly curved.
Teleomorph: ascomata apothecia, 0.5-1.5 (-2.5) × 0.12-0.3 (-0.4) mm, scattered or crowded and contiguous, elongate, sessile, elevated, occasionally furcate, the ends often acute. Disc usually well exposed, densely bluish to mauve-grey pruinose. Exciple thin, even, non-pruinose, K–. Epithecium brown. Hymenium 80-90 (-100) μm tall. Interascal tissue composed of pseudoparaphyses, septate, branched, often richly anastomosed, the apices not or rarely slightly swollen. Asci clavate to cylindric-clavate, fissitunicate, 8-spored. Ascospores (16-) 20-23 (-27) × (5-) 6-7 (-8) μm, ± elongate-clavate to fusiform, 3-septate, thick-walled, smooth, with a narrow gelatinous sheath, sometimes becoming brownish and verrucose when old.
Chemistry: thallus C–, K–, KC–, Pd–, UV– (no lichen products detected by TLC).
Assessed by Woods & Coppins (2012) as Endangered (D) and Nationally Rare. It is a former BAP species and is listed under Section 41 of the NERC Act 2006.
The prominent apothecia with ± open, grey-blue pruinose discs with black, naked margins are distinctive. It is distinguished from Opegrapha demutata by the larger apothecia, shorter conidia and larger ascospores.
South & south-west England (N and S Devon, Dorset), Channel Islands (Alderney). BLS map here.
On steep limestone, mortared walls, ± basic sandstone or slate rocks; very rare.