Hemiaustroboletus, a new genus in the subfamily Austroboletoideae (Boletaceae, Boletales)

The present study describes Hemiaustroboletus gen. nov. in the subfamily Austroboletoideae (Boletaceae). Hemiaustroboletus is supported by morphological and molecular data using LSU and RPB2 regions. Additionally, its geographic distribution and intraspecific variation were inferred using ITS sequences. The genus is characterised by pileate-stipitate basidiomata; purple, brown, reddish-brown, orange-brown to dark brown vinaceous pileus; whitish or lilac to vinaceous context and a subclavate stipe. Microscopically, it is characterised by ornamented, slightly verrucose, cracked to perforated brown basidiospores. Two species are described within the genus, Hemiaustroboletus vinaceobrunneus sp. nov. and H. vinaceus sp. nov. Hemiaustroboletus vinaceus sp. nov. is morphologically similar to Austroboletus gracilis, which suggests they may have been confused in the past. This study presents the phylogenetic placement, microscopic structures, detailed morphological descriptions and illustrations of both new species.