Abstract
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).