Two New Species of Lactifluus (Basidiomycota, Russulales) Sections Piperati and Albati Inhabiting Tropical Quercus Forests of Eastern Mexico

Mexican species of Lactifluus have often been identified using names of morphologically similar Old World taxa. However, integrative approaches combining morphological and molecular data have revealed a high level of previously unrecognized diversity in the region. Here, two new species from lowland tropical Quercus forest are described: one in section Piperati (subgenus Lactifluus), characterized by pale yellow basidiomes and another in section Albati (subgenus Lactariopsis), with whitish basidiomes. The two taxa are distinguished by a unique set of macro- and micromorphological features, and their recognition is strongly supported by phylogenetic evidence from a concatenated dataset including nc ITS rDNA, nc 28S rDNA and the 6–7 region of the second largest subunit of the RNA polymerase II (rpb2).