Unveiling the cryptic Neotropical species of from the Southern Cone: phylogenetic and morphological analysis.

Global fungal diversity is estimated at about 6.2 million species, but only 150 000 are currently described. Molecular studies reveal that this diversity is often underestimated, especially in less-studied regions. , a genus of ramarioid fungi, has a wide distribution in areas with temperate and tropical climates. However, in southern South America, research on species has been scarce, with only a few studies conducted in Argentina covering the morphology of a few species. This research aims to analyze species in Argentina, exploring their morphology, ecological roles, and distribution. Four different ecological regions across Argentina were sampled. Molecular data (Sanger and next-generation sequencing [NGS] technology) were obtained to construct their phylogenetic relationships. Our results show a greater diversity of than previously known. Eight taxa are described here, four of which are new species to science (, and ). Additionally, a neotypification is proposed for . For the other three species (, and ), we provide new molecular data and elucidate their phylogenetic relationships with other previously described species. In addition, a key to species of from Argentina and Chile is included to facilitate identification of known taxa. Finally, most species richness is associated with tropical and subtropical forests.