Crassisporium and Romagnesiella: two new genera of dark-spored Agaricales

Abstract

A systematic study of a rare and enigmatic European species, Galerina clavus Romagn., is presented. Phylogenetic analyses show it to be most closely related to Pachylepyrium carbonicola (A.H. Sm.) Singer and P. funariophilum (M.M. Moser) Singer (Strophariaceae). Investigation of additional species of Pachylepyrium suggests this genus is polyphyletic as the type species, P. fulvidula (Singer) Singer, is nested in the Tubariaceae Vizzini based on multigene phylogenetic analyses. Pachylepyrium nubicola Singer is allied with Pholiota (Fr.) P. Kumm. based on high ITS similarity, and P. carbonicola and P. funariophilum, together with G. clavus, form a clade among a consortium of Strophariaceae Singer & A.H. Sm. and Hymenogastraceae Vittad. As a result, we propose Romagnesiella gen. nov. to accommodate G. clavus, for which a taxonomic description is given and lectotype and epitype are designated. The genus Crassisporium gen. nov. is proposed to encompass Pachylepyrium funariophilum (of which P. carbonicola is considered a younger taxonomic synonym), P. chilense M.M. Moser, and P. squarrulosum Singer. Crassisporium is distinguished from Romagnesiella by its thick-walled basidiospores and occurrence in burnt habitats. The identities of the morphologically similar Tubaria umbonata S. Lundell, T. embolus (Fr.) Sacc. and T. minima J.E. Lange are also discussed.

Key words:

• Agaricoid clade
• carbonicolous fungi
• Hymenogastraceae
• Pachylepyrium
• Strophariaceae
• taxonomy
• taxon sampling
• types

Acknowledgements

The authors are grateful to staff at herbaria G (P. Clerc), IB (R. Kuhner), LIP (R. Courtecuisse and C. Lécuru), MICH (R. Rabeler, P. Rogers), MPU (V. Bourgade, L. Gomel and M.-J. Mauruc), PC (B. Buyck), PERTH (N. Bougher), and the USDA Forest Service, Luqillo, Puerto Rico (D. J. Lodge) for loan of collections. Egon Horak (Innsbruck, Austria) is acknowledged for his study on Sardinian collections sent by M. Contu. Régis Courtecuisse (Lille, France) is also acknowledged for his valuable suggestions and bibliographic expertise. Aaron Wolfenbarger, Emily Giles, Whitaker Hoskins, Sarah Sprague, and Christine Braaten provided laboratory assistance at the University of Tennessee. Three anonymous reviewers and the Associate Editor, Karen Hansen, provided critical feedback that helped improve this paper. Research was conducted at the University of Tennessee, Université Lille Nord de France, and Università di Torino.

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Additional information

Funding

This work was supported by the U.S. National Science Foundation under Grant DEB-0949517.