Taxonomy and phylogeny of yellow Clavaria species with clamped basidia—Clavaria flavostellifera sp. nov. and the typification of C. argillacea, C. flavipes and C. sphagnicola

Abstract

This study explores species limits of a group of Clavaria species with taxonomic and nomenclatural problems and discusses the phylogeny and circumscription of the genus. The nuc 28S rDNA (28S) and internal transcribed spacer region phylogenies resolve species relationships, and the ITS is shown to be an adequate barcode marker for Clavaria. Yellow, clamped species of Clavaria are distributed in two clades, (i) C. flavostellifera, sister to C. incarnata and C. asterospora in ITS analyses, characterized by producing ornamented spores, and (ii) C. argillacea-C. citrinorubra-C. flavipes-C. sphagnicola, with smooth spores. Clavaria flavostellifera is described as new species based on morphological and molecular characters. Molecular evidence that supports C. sphagnicola as distinct from C. argillacea is provided. The usefulness of spore ornamentation as a taxonomic character is discussed; it is present only in some taxa and then only on spores trapped in the hymenium. Descriptions of C. argillacea, C. flavipes and C. sphagnicola are provided, along with color photographs and a key to yellow species of Clavaria with clamped basidia. Camarophyllopsis and Clavicorona are recovered within a paraphyletic Clavaria in our 28S phylogeny. Clampless contextual hyphae and narrow, slightly thick-walled mycelial hyphae are proposed as synapomorphies of Camarophyllopsis and Clavaria.

• Basidiomycota
• Camarophyllopsis
• Clavariaceae
• Clavicorona
• species delimitation
• spore ornamentation

Acknowledgments

We are indebted to Slavomir Adamčík for his valuable comments and for lending us interesting material. We express our gratitude to Maria Prieto for critical revision of the manuscript and advice on phylogenetic analyses. We acknowledge the curators of BIO (M. Herrera), K (B. Aguirre-Hudson) and PC (B. Buyck) for arranging loans. L. Gaisler, L. Tábi and J. Kuriplach are thanked for providing photos of C. flavipes and C. flavostellifera. We thank Joshua Birkebak for valuable advice and for kindly sharing notes on the morphology specimens sequenced by him. Miguel Ángel Ribes provided photographs of C. argillacea and useful comments on his gatherings. We are also grateful for the help of two anonymous referees for providing valuable inprovements to this manuscript. This work was partially supported (I. Olariaga) by a researcher training grant from the Basque government (2002/2003) and (I. Kautmanová) by a grant from the European Commission’s (FP6) Integrated Infrastructure Initiative programme, SYNTHESYS (ES-TAF 4137) and national project VEGA 02/0088/13.