Hidden fungal diversity from the Neotropics: Geastrum hirsutum, G. schweinitzii (Basidiomycota, Geastrales) and their allies

Taxonomy of Geastrum species in the neotropics has been subject to divergent opinions among specialists. In our study, type collections were reassessed and compared with recent collections in order to delimit species in Geastrum, sect. Myceliostroma, subsect. Epigaea. A thorough review of morphologic features combined with barcode and phylogenetic analyses (ITS and LSU nrDNA) revealed six new species (G. neoamericanum, G. rubellum, G. brunneocapillatum, G. baculicrystallum, G. rubropusillum and G. courtecuissei). In additon, the presence of hairs on the exoperidium, a commonly used feature to diagnose Geastrum species, proved to be ineffective because it is a derived character within subsect. Epigaea.

新热带界地星属（Geastrum）物种的分类学界定，长期以来在分类学专家中存在诸多分歧。本研究对模式标本进行了重新评估，并与近期采集的标本进行比对，以明确地星属菌丝体组（sect. Myceliostroma）平卧亚组（subsect. Epigaea）的物种边界。通过对形态学特征的全面分析，结合DNA条形码分析与基于ITS及LSU nrDNA的系统发育分析，本研究共发现6个新种：新美地星（G. neoamericanum）、红柔地星（G. rubellum）、褐毛地星（G. brunneocapillatum）、晶杆地星（G. baculicrystallum）、细小红地星（G. rubropusillum）以及库尔特地星（G. courtecuissei）。此外，以往常用于地星属物种鉴定的外包被被毛特征，经证实并不具备分类鉴定价值，因为该特征实为平卧亚组（subsect. Epigaea）内的衍生性状。