Four new species of Morchella from the Americas

ABSTRACT

Morphological and molecular phylogenetic studies of true morels (Morchella) in North America, the Dominican Republic, Venezuela, Ecuador, and Peru led to the discovery of four undescribed species of Morchella. Two new species in the Elata clade, one from the Dominican Republic, initially distinguished by the informal designation Mel-18, and a newly discovered sister species from northern Arizona, are now recognized. Mel-18 is described as a novel phylogenetically distinct species, M. hispaniolensis. Its sister species from Arizona is described as M. kaibabensis, also recovered as an endophyte of Rocky Mountain juniper. Two additional species in the Esculenta clade, M. peruviana discovered in Peru and M. gracilis (previously reported as Mes-14) from the Dominican Republic, Venezuela, and Ecuador, are described as new. We also demonstrate that scanning electron microscopy (SEM) imaging of ascospores using rehydration/dehydration/critical point drying preparation techniques provides for enhanced resolution of spore wall surfaces, thereby increasing the number of morphological traits available to assess differences among otherwise closely related species.

KEYWORDS:

• Arizona
• Ascomycota
• Dominican Republic
• Ecuador
• endophytes
• molecular phylogenetics
• Morchellaceae
• Peru
• Pezizales
• Venezuela
• 4 new taxa

ACKNOWLEDGMENTS

We thank Robert H. Proctor for calling our attention to the IQ-TREE software package that was used to conduct phylogenetic analyses and Gail Doehring and Nathane Orwig for skilled technical assistance in various aspects of this study. We thank the Geology Department of SUNY Cortland for providing T.J.B. access to their scanning electron microscope and technical support. We also thank the curators and collection managers of the following herbaria for their assistance: A. Elizabeth Arnold and Joseph Aaron Myers, Robert L. Gilbertson Mycological Herbarium (ARIZ); David Giblin, University of Washington Herbarium (WTU); and Régis Courtecuisse and Christophe Lécuru, Université de Lille, France (LIP). Donald H. Pfister and Pierre-Arthur Moreau provided valuable presubmission comments of the manuscript and greatly improved the presentation.

Additional information

Funding

T.J.B., D.J.L., and S.A.C. were funded by grants from the National Science Foundation Biodiversity Surveys and Inventories Program to the State University of New York College at Cortland (DEB-9525902 and DEB-0103621) for field work in the Dominican Republic. The USDA Forest Service Center for Forest Mycology Research Forest Products Laboratory provided additional logistical support for Caribbean work via a Joint Venture Agreement with SUNY Cortland. Field work in Ecuador by T. Læssøe was supported by a Danish government RUF grant.