Two new species of Boletaceae (Hortiboletus rubroreticulatus and Tylopilus aurantiovulpinus) discovered during an investigation of the mycobiota of Central Vietnam (Kon Chu Rang Nature Reserve; Ta Dung National Park; Bidoup—Nui Ba National Park; Kon Ka Kinh National Park) are described on the basis of molecular and morphological data. Illustrated descriptions of their macro- and microscopic features and discussion on similar taxa are given. Additionally, eight species which were recorded for the first time in Vietnam are listed and illustrated here. A new combination Kgaria virescens was made for one of these species. These results were confirmed by the phylogenetic analysis based on nrITS1-5.8S-ITS2, nrLSU, and tef1α regions.

Data on the species diversity of the genus Micropsalliota in Vietnam is still insufficient. In the current paper, three new species with small basidiomata (M. appendiculata, M. inflata, and M. suricatoides) are collected from Dong Nai and Gia Lai provinces of Vietnam, and identified based on morphological and molecular data. Micropsalliota appendiculata is characterized by an appendiculate margin of pileus, M. inflata – by red pileus and inflated pileipellis hyphae cells, and M. suricatoides possesses beige pileus with brown fibrils and stipitipellis hyphae with capitate apices. The study is provided with photographs of basidiomata, illustrations, descriptions of macro- and micromorphological features, and phylogenetic trees to show the position of the three new species. Discussion on similar taxa is also given.

Coniolepiota, a genus within the family Agaricaceae, described in 2011, has been considered monotypic, embracing one species, C. spongodes, distributed in tropical Asia. Based on the morphological study and molecular analysis, two species of Coniolepiota viz. C. spongodes and C. alexandri are recognized from Southern Vietnam. Coniolepiota spongodes, a new record to Bu Gia Map National Park (Binh Phuoc), possesses attractive lilac basidiomata of medium size with flocculose squamules, white spores, and T-shaped pileal elements. Coniolepiota alexandri, proposed as a new species from Cat Tien National Park (Dong Nai), shares all the features listed above but has a different colour (white) of basidiomata. Detailed descriptions of the new species and the new record are presented herein. Field photographs of the collected basidiomata, illustrations of the microscopic structures, and phylogenetic trees generated from datasets of nrITS and LSU sequences, are provided.