Pyriformiascoma Daranagama, E. Camporesi & K.D. Hyde, gen. nov., Indexfungorum number: IF809526
Etymology: In reference to the pear-shaped ascomata
Saprobic on wood, stems and twigs. Sexual morph: Ascomata immersed, visible as blackened, slightly raised, solitary, globose to conical areas, with ostiolar canal, diam. at the base, obpyriform, ostiolar canal comprising host cells, broad than high. Peridium comprising two cell layers, outwardly comprising dark brown cells of textura oblita and inwardly comprising hyaline cells of textura angularis. Paraphyses 2.5 µm diam., numerous, filamentous, septate. Asci 8-spored, unitunicate, cylindrical, short-pedicellate, apically rounded, with cytoplasm forming fork-like invagination below indistinct apical apparatus, J-, apical apparatus, Ascospores overlapping uniseriate, unicellualr with hyaline dwarf cell at base, larger cell olivaceous green, inequilaterally oblong-ellipsoidal, germ slit lacking. Asexual morph: Conidiophores simple, pale brown, rarely branched. Conidiogenous cells terminal, single, cylindrical. Conidia light brown, globose.
Type species: Pyriformiascoma trilobatum Daranagama, Camporesi & K.D. Hyde 2015
Notes: Pyriformiascoma is treated as a new genus in this study based on unique morphological characters and its phylogenetic placement. Pyriformiascoma contains a characteristic apical apparatus, which does not stain in blue in Melzer’s reagent with cytoplasm forming fork-like invagination below indistinct apical apparatus. This unique character makes it different from many other known genera included in Xylariaceae. Pyriformiascoma and Anthostomella share certain common characteristics such as Pyriformiascoma trilobatum has unicellular ascospores with hyaline dwarf cell as in Anthostomella but the ascospores are olivaceous green and lack a conspicuous sheath or germ slit. The peridium texture (i.e. hyaline cells of textura angularis and dark brown cells of textura oblita) also differs from that of Anthostomella, which usually possess hyaline cells of textura angularis and dark brown cells of textura irregularis. The asexual morph is different from the described asexual morphs for Anthostomella (Lu and Hyde, 2000b). The asexual morph of Pyriformiascoma trilobatum has brown simple conidiophores with globose, brown conidia. Pyriformiascoma trilobatum clustered as a basal clade to both the hypoxyloid and xylarioid Xylariaceae as a separate lineage parallel to Creosphaeria sassafras and Barrmaelia macrospora.