Ten species of Boletaceae with ornamented basidiospores are described and illustrated from temperate forests in the state of Oaxaca, Mexico. Boletellus ananiceps is recorded for the first time in Mexico, and Austroboletus gracilis, Boletellus flocculosipes, B. chrysenteroides, B. pseudochrysenteroides and Heimioporus ivoryi are first records from Oaxaca. While Aureoboletus russellii, B. coccineus, H. betula, Strobilomyces confusus only increase distribution in Oaxaca state.All species are described and illustrated and identification keys for the described genera are provided. The studied specimens were deposited in the national herbaria ENCB, ITCV and MEXU-UNAM.

Matsutake fungi include a complex of edible mushrooms highly prized worldwide, particularly in Japan where they are considered one of the most luxurious ingredients. These species establish ectomycorrhizal symbioses with angiosperms and gymnosperms in the Northern Hemisphere and in North America only three species are currently known. In the present contribution a fourth species of this geographical area is described, Tricholoma colposii sp. nov. is described from Veracruz state, in eastern Mexico based on morphological and molecular (nrITS) data. This species is characterized by middle size basidiomata, with orange brown to brown pileus and stipe, squamose when young and with appressed scales in maturity, cylindric, fibrillous to scaly stipe, with globose to ellipsoid (4.5–)5–6 (–7) × (3–) 4–5 (–6) μm smooth spores, sporomes with sweet fruit odor and raw green bean flavour. The species grows associated with Pinus teocote forests. The macro- and micromorphological characters in conjunction with the nrITS-based phylogenetic analysis using Maximum Likelihood method and Bayesian inference support the proposal of this new species of Mexican matsutake. Detailed descriptions, photographs and comparisons with phenetic and phylogenetic related species are presented.

Background and Aims: Xerocomellus is a genus of the Boletaceae family, characterized by the small to medium, boletoid to gastroid basidiomata, usually with areolate pileus, and smooth to ornamented basidiospores. So far only two species are known from Mexico. The aim of this study is to describe a new species of Xerocomellus, based on morphological, molecular and ecological data. Methods: Sampling of studied specimens was carried out in Nuevo León state, northeastern Mexico (2009 and 2016). Classic protocols for macrofungi were followed. Hand cut sections of specimens were made and mounted in KOH and Melzer reagent to observe microstructures. The identification of the putative host tree was made in the botanical herbarium CFNL of the Facultad de Ciencias Forestales, Universidad Autónoma de Nuevo León; the type of forest was identified according to field observations and satellite images. DNA was extracted from three different collections. The ITS region and the gene LSU were obtained and analyzed. The material was deposited in the mycological collections of the herbaria “José Castillo Tovar” (ITCV) of the Instituto Tecnológico de Ciudad Victoria and CFNL. Key results: Xerocomellus carmeniae differs from other Xerocomellus species by the following combination of characteristics: boletoid basidiomata, reddish areolate pileus, yellowish stipe, and basidiospores of 10.5-13.6 × 5.7-7.8 µm, elongate, sometimes truncate. Conclusions: Xerocomellus carmeniae is the third species of this genus known from Mexico and is putatively associated to Quercus cambyi. Some specimens show an aberrant form, but more studies are recommended to evaluate a possible transition to a secotioid form.

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Tuber mixtecorum is described as a new species from Mexico based on morphological and molecular evidence. This species belongs to the Maculatum clade and is characterized by its subtomentose to glabrous, whitish to pale brown peridium, dark brown gleba, ellipsoid reticulate-alveolate ascospores (15–33.9 × 11.3–23.3 µm), and the putative mycorrhizal association with Quercus castanea in Quercus-Pinus dry mixed forests.