Pyronema omphalodes

A pyrophilous species typical of burnt ground or fireplace debris, with orange, globose, irregular ascomata measuring 0.5 to 1.8 mm across, coalescent and densely clustered into irregular masses.

Medullary excipulum composed of large globose to vesiculose, hyaline, thin-walled hyphae 20 to 60 µm in diameter, gradually decreasing in size towards the outer layer (ectal excipulum).

Asci cylindrical, 8-spored, operculate, 150 to 200 µm long, 10 to 14 µm wide, uniseriate, inamyloid in Melzer's reagent.

Paraphyses filiform, septate, with apex only very slightly enlarged up to 3 to 5 µm wide, branched at the base, containing abundant orange granulations inside, scarcely or not protruding beyond the asci.

Ascospores cylindrical-ellipsoidal, smooth, hyaline or with very faint yellowish intracellular pigment, thin-walled, 12 to 14.5 µm long, 6.5 to 8 µm wide, without guttules (homogeneous interior).

Closely related to Pyronema domesticum, which has broader spores (9 to 11 µm wide).