Cercopemyces crocodilinus, a new genus and species related to Ripartitella, is described from North America

Abstract

Cercopemyces is described as a new genus based on collections of a newly discovered agaricoid species from the arid Cercocarpus forests of Utah and Colorado. The new genus is near Ripartitella and Cystodermella based on nLSU, rpb1 and ITS molecular sequences but distinctly different from these taxa. The ornamented basidiospores and inflated cells in the scales of the pileus surface of Cercopemyces indicate a close relationship to some species of Ripartitella, and the molecular analyses support the sister group relationship. Morphologically Cercopemyces crocodilinus is reminiscent of the genus Amanita in the field, but the inamyloid, cyanophilic, ornamented basidiospores and lack of acrophysalidic hyphae in the trama indicate otherwise. A rare eastern USA species, Ripartitella ponderosa, is transferred to Cercopemyces based on morphological and molecular data.

• Cercocarpus
• Cystoderma
• Cystodermella
• Great Basin
• ITS
• new combination
• nLSU
• phylogenetics
• rpb1

ACKNOWLEDGMENTS

We thank the Utah Agricultural Experiment Station for financial support. This is Utah Agricultural Experiment Station paper 8480. We also thank Dr Beatriz Ortiz Santana, USDA Forest Service Northern Research Station, for providing a collection of Ripartitella brasiliensis that came from research supported by the National Science Foundation, Biodiversity Surveys and Inventories Program (NSF Awards DEB-0103621, DEB-9525902) to TJB and D.J. Lodge (Research Foundation of the State University of New York, College at Cortland, in collaboration with the USDA Forest Service, Center for Forest Mycology Research, Forest Products Laboratory, Madison, Wisconsin). Mr Jack Jones found the Colorado collection and we gratefully acknowledge his contribution to the discovery of this new taxon. The image of the fresh specimens was taken by Mr Ed Lubow of Colorado and he is gratefully acknowledged for this contribution. Two anonymous reviewers also provided important helpful suggestions for improving the manuscript and we do thank them.