O gênero Geastrum (Geastrales, Basidiomycota): uma nova espécie brasileira de fungo estrela-da-terra

Abstract

The genus Geastrum Pers. is the most representative (100-120 spp) of the family Geastraceae and is fundamentally characterized by its basidiomes with starlike dehiscence, therefore them known as "earthstars". It has distribution in all continents except Antarctica, the last estimate made in 2019 reported 67 species of Geastrum in Brazilian territory, which represents about 55% of the known species. This genus presents a great pharmacological and biotechnological potential, besides the important participation in the cycle of molecules such as carbon and nitrogen, reinforcing the importance of knowing and correctly identifying these organisms. The identification of fungi using only morphological characters, in some cases has proven to be insufficient due to the presence of cryptic and semi-cryptic species. The analyses were based on specific methodologies for Geastrum and adding new taxonomic characters (size of hyphae of the exoperidium, size of the ornamentation of the basidiospores, crystals found in the rhizomorpha), besides comparative studies using molecular data (sequencing of ribosomal DNA regions). As a result of this project, a new species of Geastrum typical of the Atlantic Forest was described and submitted to the journal Folia Geobotanica (PRUHONICE). Geastrum tupiense sp. nov. was named in honor of the Tupinambá indigenous people who inhabited the coastal zone of Brazil. In addition, the present work contributed with the generation of new sequences of Geastrum for the Neotropical region, elucidating the position of these individuals in the systematics of the genus and promoting a greater evolutionary and systematic understanding of the group.