Helvella fuscolacunosa

A recently described taxon with microscopic characteristics virtually identical to Helvella lacunosa, requiring molecular data for reliable separation; this determination was made following the criteria of a leading expert on the genus who knew the locality thoroughly and identified it in the field, one distinction being the very dark greyish-brown hymenium compared to the bluish-black hymenium of Helvella lacunosa.

Ectal excipulum with terminal hyphae, cylindrical, erect, septate, moderately thick-walled, with greyish-brown intracellular pigment.

Asci 8-spored, uniseriate, operculate, up to 350 µm long, 13-15 µm wide, inamyloid in Melzer's reagent.

Paraphyses filiform, simple, septate, with brownish intracellular pigment, 3-5 µm wide, with very slight swellings, projecting slightly above the asci.

Ascospores ellipsoidal, smooth, hyaline, thin-walled, with a large central oil droplet occupying almost the entire spore volume.

Herbarium material available: JTP2463/25.