Septal Structures in Apothecial Tissues of the Tribe Aleurieae in the Pyronemataceae (Pezizales, Ascomycetes)

Abstract

The fine structure of septa in asci, ascogenous hyphae, paraphyses, and excipular cells of apothecia is described in species of Aleuria, Anthracobia, Leucoscypha, and Octospora of the tribe Aleurieae, subfamily Scutellinioideae ofthe Pyronemataceae. An electron-opaque, hemispherical structure similar to that present in the Ascobolaceae was found in the ascal septa of all taxa. The hemispherical structure in the Aleurieae differs, however, in zonation and in the presence of an electron-translucent band bordering the pore in most species. Similar pore structures were found in the ascogenous hyphae of all species studied. Septal pores of paraphyses and excipular cells possess an electron-opaque, lamellate structure characteristic of taxa in the Pezizales. Evidence suggests that septa of genera in this tribe are more similar to those ofthe Ascobolaceae than to those ofthe Pezizaceae. Phylogenetic aspects ofthe data are discussed.