Gastrosporium simplex: Ein pannonischer Steppenpilz aus dem Nordtiroler Karwendel-Gebirge

Gastrosporium simplex (‘steppe truffle’) is a rare, hypogeous to epigeous, endangered gastroid fungus belonging to the Gastrosporiaceae (Phallales, Agaricomycetes, Basidio mycota) family. Previously found in the Pannonian region of Austria, it has now been discovered in the Fragenstein nature reserve near Zirl on the south-western edge of the Karwendel mountains, marking its first recorded occurrence in North Tyrol. The fungus’s occurrence is limited to a small area of dry, south-facing limestone grassland, which is part of a xerothermic habitat in succession from former sheep and goat grazing land. The most important characteristics of the fungus (fruit body, rhizomorphs, basidia and spores), as determined by macro- and microscopic examination, correspond to species descriptions of G. simplex from other regions in Eurasia, as well as from the American continent. Molecular rDNA data confirm its affiliation with this species, and a phylogenetic tree calculation including related species shows that G. simplex, together with G. gossypinum, forms a monophyletic family within the order Phallales (Agaricomycetes). Although G. simplex is found worldwide, it is globally considered a near threatened species which is endangered with extinction in some European countries (https://www.iucnredlist.org/species/63579691/63579694#population). This is due to the fact that the fungus usually forms only small populations within fragmented, xerothermic dry grassland habitats, which are declining and particularly susceptible to human impact.