Helvella acetabulum

Terminal hyphae of the outer surface cylindrical, septate, with brown intracellular pigment, conferring its pubescent appearance.

Medullary excipulum of textura intricata, with filamentous, densely interwoven hyphae, 4-7 µm wide, septate with simple septa.

Ectal excipulum hyphae globose to vesiculose, with brownish intracellular pigment, up to 25 µm long.

Asci cylindrical, uniseriate, 8-spored, up to 140 µm long, inamyloid in Melzer's reagent.

Paraphyses filiform, smooth, hyaline, with few prominent septa, unbranched, with a very subtle, almost imperceptible apical swelling, projecting slightly above the asci.

Ascospores ellipsoidal, smooth, hyaline, with a large central oil droplet occupying well over half the total spore volume.