Nitschkia grevillii

Saprophytic fungus on decaying decorticated dead wood in riparian woodlands (on Populus or Alnus), appearing as small spherical granules 0.35–0.50 mm in diameter, black with a verrucose surface, lacking an ostiolar opening, releasing spores through irregular disintegration of the ascoma wall.

Outer ascoma wall composed of very compact, dark hyphal tissue 40–60 µm thick, heavily laden with black intracellular pigment.

Asci clavate, short-pedicellate, 8-spored, measuring 28–45 µm long by 5–6.5 µm wide, with biseriate (occasionally triseriate) to irregular spore arrangement especially in the upper part, inamyloid in Melzer's reagent.

Paraphyses not observed.

Ascospores cylindrical, smooth, hyaline, thin-walled, measuring 8–10 µm long by 2–3 µm wide, with a median septum and two to four coarse oil droplets (guttules) inside.