Septal Structures in Apothecial Tissues of the Pezizaceae (Pezizales, Ascomycetes)

Abstract

Septal structure of asci, ascogenous hyphae, paraphyses, and excipular cells in the apothecia of nine species of Pezizaceae were examined at the ultrastructural level. Electron-opaque, convex and biconvex bands were associated with septa at the bases of young asci and with ascogenous septa. The septal pore in older cells was occluded with electron-opaque, amorphous material, and in some cases secondary wall material developed over the pore. The septa of paraphyses had convex bands and/or lamellate structures often with associated Woronin bodies. A consistent feature of the septa of excipular cells was the presence of lamellate structures and Woronin bodies adjacent to or sometimes located within the pore. None of the septal types appeared to be of taxonomic value at or below the generic level. We recognize the lamellate structure in somatic cells as the Peziza septal type in contrast to the Neurospora septal type found in other Ascomycetes.