Sclerococcum stygium

On decorticated decaying wood on the ground in riparian woodland, with sessile, disc-shaped apothecia 1 to 1.8 mm across, blackish, attached to the substrate by their center, and easily separable.

Ectal excipulum of textura angularis, with thin- to slightly thick-walled hyphae 14 to 28 µm long and 12 to 18 µm wide, containing faint greyish intracellular pigment.

Upon reaching the margin, the ectal excipular hyphae become globose, clavate to pyriform, thick-walled, with abundant blackish-brown intracellular pigment, 7 to 12.5 µm long and 6.5 to 9.6 µm wide.

Asci cylindrical to subclavate, eight-spored, bitunicate, 65 to 80 µm long, 9 to 14 µm wide, with biseriate to irregular spore arrangement inside the ascus, and an amyloid apical reaction in Melzer's reagent.

Paraphyses filiform, slender, sparsely branched, 1.6 to 2.5 µm wide, septate, with apical enlargements of the terminal cell of 3.5 to 5 µm, not noticeably exceeding the height of the asci.

Ascospores cylindrical-ellipsoidal to slightly fusiform, thick-walled, pale brown under the microscope, with a central septum, 15 to 21 µm long, 4 to 5.5 µm wide, with characteristic longitudinal striae and oil droplets of varying size inside.

Herbarium material available: JTP2129/24.