Swinscowia calcarea  

Thallus greenish grey to greyish pink in fresh material, pale grey in dried specimens, continuous, endolithic, penetrating up to ca 4 mm below the rock surface, delimited from surrounding colonies by a dark hypothalline line, usually containing either ascomata and micropycnidia or only macropycnidia.

Anamorph of two types. Macropycnidia 120-180 µm diam, subglobose, completely immersed in the thallus and substrate, hyaline or pale pink, sometimes brownish at the apex, without an involucrellum. Conidiogenous cells 6-13.5 x 2-4 µm, cylindrical, tapered towards the apex, proliferation unknown. Macroconidia (13-) 15-19.5 (-22.5) x (3.5-) 4-4.5 (-5.5) µm, average length/width ratio 4:1, cylindrical to cylindric-fusiform, hyaline, with 2 to 4 septa, most frequently 3-septate, variably constricted at the septa, the apices rounded, each with a small gelatinous appendage. Micropycnidia similar to macropycnidia but smaller, 80-120 µm diam and conidiogenous cells 6-8.5 x 1.5-2 µm in size. Microconidia (2-) 3-4 (-5) x 1-1.5 µm, cylindrical, sometimes slightly constricted in the mid region, hyaline, aseptate, presumably spermatial in function.

Teleomorph: Ascomata perithecial, 200-400 µm diam, obpyriform to subglobose, immersed and difficult to distinguish from the thallus surface, hyaline or pinkish, the ostiolar region pigmented brown or greenish brown, their former position in the thallus visible as small cavities. Interascal tissue not noted. Asci 90-150 x 10-13 µm, narrowly clavate, fissitunicate. Ascospores arranged ± biseriately, (15-) 17-22 (-23) x (4-) 5.5-7 (-8) µm, cylindric-fusiform, hyaline, 3-septate, constricted at the septa and most so at the median septum, rarely fragmenting at the mid point, without a gelatinous sheath.