Caloboletus luolongensis sp. nov. and supplementary notes on Chenrenyua longispora (Boletaceae) from Guizhou Province, China

Caloboletus luolongensis sp. nov . is described from Guizhou Province, southwestern China, based on morphological characters and multilocus phylogenetic analyses. It is characterized by a rugose pileus with a slightly incurved margin, a longitudinally reticulate stipe that is rose-red over its middle and lower parts, and a context that bruises blue when injured. Supplementary notes on the known bolete Chenrenyua longispora are also provided based on newly collected materials from Guizhou. Phylogenetic reconstructions were performed on a combined dataset of nrLSU, nrITS, TEF1-α, and RPB2 sequences. The new Caloboletus species is morphologically distinct and forms a well-supported, independent phylogenetic lineage, clearly separated from all previously described congeners. The Guizhou population of Chenrenyua longispora shows intraspecific morphological differences compared with the original protologue, and molecular data confirm its conspecificity. This study enriches the diversity of Caloboletus and extends the known geographical distribution and range of morphological variation of C. longispora . These findings further demonstrate that the species diversity of Boletaceae in southwestern China remains underestimated and highlight the importance of integrative taxonomic studies combining morphology and multilocus phylogenetic evidence.