Two new Lactarius species from a subtropical cloud forest in eastern Mexico

Abstract

Two species of Lactarius from the subtropical montane cloud forest of central Veracruz are described as new. Both species are placed in subgenus Lactarius based on an accurate study of macro- and micromorphological features and supported by molecular phylogenetic analyses of a single nuc rDNA ITS1-5.8S-ITS2 (ITS), a concatenated ITS, D1, and D2 domains of nuc 28S rDNA (28S), and part of the second largest subunit of the RNA polymerase II (rpb2) (6–7 region) sequence datasets. In the phylogenetic reconstruction presented, the two species appear nested in two clearly distinct, well supported clades that reveal their phylogenetic position among members of subgenus Lactarius (= subg. Piperites s. auct.), a complex group of which a worldwide phylogeny requires further study. According to field observations, both taxa are possible ectomycorrhizal associates of Quercus spp. and one of Fagus grandifolia var. mexicana. Taxonomic descriptions based on the study of specimens gathered during fieldwork from 2012 to 2014 are presented. Descriptions are accompanied with illustrations of macro and micromorphological characters and a discussion of related species is provided.

• ectomycorrhizal fungi
• Lactarius
• neotropical fungi
• Piperites
• Russulales
• subgenus Piperites

Acknowledgments

We appreciate the collaboration in the monitoring of Lactarius in the field and assistance in the laboratory by Bióls. D Ramos and JC Corona (Instituto de Ecología AC). We thank MScL Navarro for assistance in some molecular procedures. We recognize the support given by CONACYT (Project 169172) for the study of ectomycorrhizal fungi associated with Fagus and a postdoctoral grant to A Ramos. Thanks to INECOL Project 20035-30890 Estudio integral de la Biodiversidad del Jardín Botánico Francisco Javier Clavijero con énfasis en el Santuario del Bosque de Niebla. We also recognize CONACYT (Project 225382) for the support of the Molecular Laboratory of the Biodiversity and Systematics Net, INECOL.