Integrative taxonomy reveals two new species of Itajahya Möller (Phallaceae, Phallales) in Brazil.

Abstract

Itajahya is a genus of phalloid fungi distinguished by a calyptra and a lamellar receptacle. Although historically treated as a synonym of Phallus, phylogenetic evidence supports its recognition as a distinct genus. In Brazil species delimitation within Itajahya has been based mainly on morphological traits, raising the possibility of overlooked diversity. Here, we investigated the diversity of Itajahya in Brazil using an integrative taxonomic approach combining morphological analyses and phylogenetic inference based on ITS, nucLSU, and atp6. Specimens were collected in the Chapada Diamantina region, northeastern Brazil. Bayesian and Maximum Likelihood analyses recovered Itajahya as a well-supported monophyletic lineage, clearly separating it from Phallus. Two new species, Itajahya mucugensis and I. payaya are described, raising from eight the number of species accepted in the genus. Both species form a well-supported clade sister which I. rosea and are distinguished from all previously described taxa by a combination of morphological and molecular characters. These findings reveal previously unrecognized diversity within Itajahya and emphasize the importance of integrative taxonomy for resolving species boundaries in phalloid fungi.