Purple haze: Cryptic purple sequestrate Cortinarius in New Zealand

ABSTRACT

Cortinarius

is a species-rich ectomycorrhizal genus containing taxa that exhibit agaricoid or sequestrate basidiome morphologies. In New Zealand, one of the most recognizable and common Cortinarius species is the purple sequestrate fungus, C. porphyroideus. We used genome skimming of the almost 100-y-old type specimen from C. porphyroideus to obtain the nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode) and partial nuc rDNA 28S (28S) sequences. The phylogenetic position of C. porphyroideus was established, and we found that it represents a rarely collected species. Purple sequestrate Cortinarius comprise multiple cryptic species in several lineages. We describe four new species of Cortinarius with strong morphological similarity to C. porphyroideus: Cortinarius diaphorus, C. minorisporus, C. purpureocapitatus, and C. violaceocystidiatus. Based on molecular evidence, Thaxterogaster viola is recognized as Cortinarius violaceovolvatus var. viola. These species are associated with Nothofagus (southern beech) and have very similar morphology to C. porphyroideus but are all phylogenetically distinct based on molecular data.

KEYWORDS:

• Genome skimming
• Nothofagus
• secotioid
• Thaxterogaster
• truffle-like
• 5 new taxa

Supplemental data for this article can be accessed on the publisher’s Web site.

ACKNOWLEDGMENTS

We thank the New Zealand Department of Conservation and the Greater Wellington Regional Council for permission to collect from National Parks and Reserves. We thank OTA and PDD herbaria for the loan of collections. We are grateful to Patricio Saldivia, Michael Heads, Shaun Pennycook, and Peter Wilson for helpful advice. We thank the anonymous reviewers and editor P. B. Matheny for their helpful comments on the manuscript.

Additional information

Funding

This study was supported in part by a University of Otago Research Grant to D.A.O., C.M.B., and T.C.S. A.R.N. is supported by a University of Otago Postgraduate Scholarship. J.A.C. is supported with funding from the Science and Innovation Group of the New Zealand Ministry of Business, Innovation and Employment.