Species diversity of the Amanita section Caesareae in South Korea

Abstract Amanita ( Agaricales , Basidiomycota ) is a well-known and the largest genus of agaric mushrooms from the family Amanitaceae . Amanita is divided into 3 subgenera and 11 sections. The section Caesareae is characterized by species with an annulated stipe, margin striate pileus, and a bulbless stipe base covered with a saccate volva. Several species in sect. Caesareae are edible (e.g. A . caesarea and A. caesareoides ), while some bear morphological similarities to poisonous species, A. subjunquillea from section Phalloideae. These species exhibit similar morphologies across broad geographic regions, even across continents. The primary objective of this study was to investigate the species diversity and taxonomic status of the A. sect. Caesareae in South Korea. Sixty-two Amanita specimens from South Korea were identified based on morphological features and phylogeny using five molecular markers (ITS + nrLSU + RPB2 + TEF1 + β-tubulin ). The phylogenetic analysis identified 15 species belonging to sect. Caesareae . Five taxa are confirmed as new to science. A detailed description of the new species and their phylogenetic placement are reported in this study. This study unveils the species diversity of Amanita sect. Caesareae in South Korea and highlights the continent- and region-specific nature of species within this section. A deeper understanding of species diversity and detailed morphological characterization will aid in distinguishing between edible and toxic Amanita mushrooms. Additionally, the study offers supporting data for future ecological, systematic, and toxin studies of the genus Amanita .