Hymenoscyphus fructigenus

Abundant species occurring on decaying acorns on the ground.

Medullary excipulum of textura intricata composed of hyaline, densely interwoven hyphae; ectal excipulum with subglobose to more or less rectangular hyphae, hyaline and arranged parallelly.

Asci cylindric-fusiform, 8-spored, uniseriate to biseriate at the apex, up to 115 µm long and 7-10 µm wide, lacking basal croziers, with an amyloid apical apparatus in Melzer's reagent.

Paraphyses filiform, slender, cylindrical, septate, only very slightly widened at the apex, barely projecting above the asci.

Ascospores fusiform, smooth, hyaline, thin-walled, with abundant vacuolar internal content, inamyloid in Melzer's reagent.