Retiboletus nigrogriseus and Tengioboletus fujianensis, two new boletes from the south of China

Two new boletes, viz. Retiboletus nigrogriseus and Tengioboletus fujianensis are described based on morphological and molecular evidence. Retiboletus nigrogriseus is characterized by a black pileus when young, gray when old, context and hymenophore staining brownish to fuliginous when injured, black, reticulate stipe with a white basal mycelium, and a subcutis pileipellis composed of uninflated hyphae with cystidioid terminal cells; T. fujianensis is characterized by a large-sized basidioma, brown to reddish brown pileus, reticulate stipe, and a trichodermal pileipellis composed of uninflated hyphae with cystidioid terminal cells. A detailed description, color photos of fresh basidiomata and line drawings of microstructures of the two new boletes are presented.