Diversity, morphological variability, and distribution of tulostomataceous fungi (Agaricomycetes) in Sonora, Mexico

Recent mycological studies in Sonora, Mexico have mainly focused on tulostomataceous fungi, a group of gasteroid Agaricomycetes with a spore-sac containing pulverulent gleba and a well-defined, hollow stipe. The aim of the present study was to analyze the diversity, morphological variability, and distribution of tulostomateceous fungi, through examining the specimens deposited in the Sonora State University herbarium over 29 years of sampling. Based on 1,266 basidiomes in 621 collections from 75 locations, 23 municipalities, and 16 vegetation types, a total of 7 genera and 37 species were identified. All genera are monospecific in Sonora except Tulostoma, with 31 defined species. Several collections remain undetermined since their morphological traits are intermediate or do not match described species. The distribution of tulostomataceous fungi was related to altitude, precipitation, and climate. Further molecular analysis of undetermined specimens must be performed in order to define the real number of species in this fungal group and to understand the boundaries among closely related genera and species.