Exploring the diversity of <i>Peziza echinospora</i> (Ascomycota, Pezizomycetes) and related species in Australia, with descriptions of the new species <i>P. austroechinospora</i> and <i>P. meridionalis</i>

<i>Peziza echinospora</i> (Ascomycota, Pezizomycetes) is a species of cup-forming fungi that bears spiny, ellipsoid ascospores and is typically found on burnt ground as a saprotrophic species. It has a cosmopolitan distribution and has been reported from Australia based on morphological studies, but this has not been confirmed with molecular data. To address this knowledge gap and explore the phylogenetic diversity within the group, we investigated the species delimitation of <i>P. echinospora</i> and related species from southern Australia, using multilocus phylogenetic analyses of nuclear rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS), partial 28S rRNA, and <i>rpb2</i> (second largest subunit of RNA polymerase II) and morphological examination of fungarium specimens. Based on these analyses, we confirm the occurrence of <i>P. echinospora</i> in Australia and formally describe two new species, <i>P. austroechinospora</i> and <i>P. meridionalis. Peziza austroechinospora</i> is typically found on burnt ground and has spiny ascospores that are larger and proportionately longer than those of <i>P. echinospora. Peziza meridionalis</i> has smooth ascospores, similarly to the closely related species <i>P. subvesiculosa</i> from the Northern Hemisphere, but with smaller ascospores and an ecology not associated with burnt soil. The occurrence of <i>Peziza meridionalis</i> as an endophyte on orchid roots is also discussed.