Revision of leccinoid fungi, with emphasis on North American taxa, based on molecular and morphological data

ABSTRACT

The leccinoid fungi are boletes and related sequestrate mushrooms (Boletaceae, Basidiomycota) that have traditionally been placed in Leccinum, Boletus, Leccinellum, and a handful of other less familiar genera. These mushrooms generally feature scabers or scaber-like dots on the surface of the stipe, and they are often fairly tall and slender when compared with other boletes. They are ectomycorrhizal fungi and appear to be fairly strictly associated with specific trees or groups of related trees. In the present study, we investigate the phylogenetic relationships among the leccinoid fungi and other members of the family Boletaceae using portions of three loci from nuc 28S rDNA (28S), translation elongation factor 1-α (TEF1), and the RNA polymerase II second-largest subunit (RPB2). Two DNA data sets (combined 28S-TEF1 and 28S-TEF1-RPB2), comprising sequences from nearly 270 voucher specimens, were evaluated using two different phylogenetic analyses (maximum likelihood and Bayesian inference). Five major clades were obtained, and leccinoid fungi appeared in four of them. Taxonomic proposals supported by our results, representing a broadly circumscribed Leccinum that includes several sequestrate genera, along with Leccinellum, are made.

KEYWORDS:

• Basidiomycota
• Boletaceae
• Octaviania
• Chamonixia
• Leccinellum
• Leccinum
• Rossbeevera
• Turmalinea
• 10 new taxa

ACKNOWLEDGMENTS

We are grateful to Gerry Adams, Timothy Baroni, Frank Bilbo, Dick Bishop, Ernst Both, Roy Halling, Jay Justice, Ron Kerner, Matt Kessler, David Lewis, Daniel Lindner, Jean Lodge, Joe McFarland, Drew Minnis, the Missouri Mycological Society, Omar P. Perdomo, Peter Roberts, Walt Sturgeon, Karen Teitelbaum, the Texas Mycological Society, and Dave Wasilewski for providing collections of leccinoid fungi.

The following herbaria kindly provided material for this study: Florida Museum of Natural History (FLAS), Harvard University Herbaria (FH), Kanagawa Prefectural Museum of Natural History (KPM), National Herbarium Nederland, Naturalis (L), New York Botanical Garden (NY), Oregon State University (OSC), Royal Botanic Gardens (K), Sam Mitchel Herbarium of Fungi at Denver Botanical Gardens (DBG), Stover-Ebinger Herbarium Eastern Illinois University (EIU), University of Michigan (MICH), and US Forest Service, Northern Research Station, Center for Forest Mycology Research (CFMR).

We also thank the following individuals for crucial assistance: Henk den Bakker, Manfred Binder, Brandon Matheny, Vera Evenson, John Haight, Roy Halling, Kate Klipp, Will Klipp-Kuo, Melissa Kuo, Andrew S. Methven, Drew Minnis, John David Moore, Takamichi Orihara, Carol Schmudde, Ray Schmudde, Jean Toothman, Else Vellinga, Bob Zordani, and the anonymous reviewers of our manuscript.

Supplemental data

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