Hymenoscyphus fraxineus

On a slender fallen twig of ash (Fraxinus) on the ground.

Medullary excipulum hyphae of textura intricata, densely interwoven, hyaline, thin- to slightly thick-walled; ectal excipulum hyphae subglobose to cylindrical, arranged in parallel, constricted at the septa, hyaline, thin- to slightly thick-walled.

Asci cylindric-clavate, 8-spored, with biseriate to irregular spore arrangement, up to 110 µm long by 12 µm wide, with croziers at their base, with an amyloid apical apparatus in IKI or Melzer's reagent.

Paraphyses filiform, smooth, hyaline, septate, gradually and slightly widening at the apex up to 3 µm wide, roughly equal in height to the asci.

Ascospores cylindric-ellipsoidal to fusiform, with one end more pointed, smooth, hyaline, very thin-walled, with abundant vacuolar internal content.

Herbarium material available: JTP1985/23.