Opegrapha sphaerophoricola
Anamorph: not known.
Teleomorph: ascomata to ca 1 mm diam., scattered or in small clusters, stromatic, black, rounded, not branched, strongly convex, becoming gyrose, sessile or immersed at the base, base not constricted, black. Exciple contiguous with the hypothecium, when young almost covering the hymenium, later expanding, composed of dark brown ± completely occluded globose to angular cells 6-8 µm diam. Epithecium 5-11 µm high, brown-black. Hymenium 60-70 µm high, hyaline, not blueing in iodine. Hypothecium brown-black, 10-20 µm high. Interascal tissue of branched and anastomosed pseudoparaphyses 2-2.5 µm diam. Asci 50-60 x 13-16 µm, clavate, tholus with a distinct ocular chamber, not blueing in iodine, 8-spored. Ascospores 15.5-19.5 (-21.5) x 5-6 µm, narrowly ellipsoid to clavate, the apex rounded and the base rounded to obtuse, 3-septate, strongly constricted at the septa, at first hyaline, with age pigmented by an irregular deposition of dark melanin deposits.
Assessed by Woods & Coppins (2012) as Data Deficient, and listed as Nationally Rare. Recent collections indicate that an assessment of Least Concern might be appropriate.
On thalli of Sphaerophorus globosus, not causing substantial necrosis.
Widespread in oceanic western Scotland, with a single record from VC4 N Devon.