A four-locus phylogeny of rib-stiped cupulate species of Helvella (Helvellaceae, Pezizales) with discovery of three new species

Abstract

Helvella species are ascomycetous macrofungi with saddle-shaped or cupulate apothecia. They are distributed worldwide and play an important ecological role as ectomycorrhizal symbionts. A recent multi-locus phylogenetic study of the genus suggested that the cupulate group of Helvella was in need of comprehensive revision. In this study, all the specimens of cupulate Helvella sensu lato with ribbed stipes deposited in HMAS were examined morphologically and molecularly. A four-locus phylogeny was reconstructed using partial sequences of the heat shock protein 90, nuclear rDNA internal transcribed spacer region 2, nuclear large subunit ribosomal DNA and translation elongation factor 1-α genes. Three clades were revealed in Helvella sensu stricto. Twenty species were included in the analysis, of which 13 are distributed in China. Three new species, H. acetabuloides, H. sichuanensis and H. tianshanensis, are described and illustrated in detail. A neotype was designated for H. taiyuanensis. Helvella calycina is a new record for China, while Dissingia leucomelaena should be excluded from Chinese mycota. Hsp90 and ITS2 are recommended as useful supplementary barcodes for species identifications of the genus.