Resolution of eleven reported and five novel Podaxis species based on ITS phylogeny, phylogenomics, morphology, ecology, and geographic distribution

Abstract

Thegenus Podaxis was first described from India by Linnaeus in 1771, but several revisions of the genus have left the taxonomy unclear. Forty-four Podaxis species names and nine intraspecific varieties are currently accepted, but most fungarium specimens are labelled Podaxis pistillaris. Recent molecular analyses based on barcoding genes suggest that the genus comprises severals pecies, but their status is largely unresolved. Here we obtained basidiospores and photographs from166 fungarium specimens from around the world and generated a phylogeny basedonr DNA internal transcribed spacer ITS1, 5.8S and ITS2(ITS), and aphylogenomic analysis of 3839 BUSCO genes from low-coverage genomes for a subset of the specimens. Combining phylogenetics, phylogenomics, morphology, ecology, and geographical distribution, spanning 250 years of collections, we propose that the genus includes at least 16 unambiguous species. Based on10 type specimens (holotype, paratype, andsyntype), four recorded species were confirmed, P. carcinomalis, P. deflersii, P. emerici, and P. farlowii. Comparing phylogenetic analysis with described species, including morphology, ecology, and distribution, we resurrected P. termitophilus and designated neotypes, epitypes, orlectotypes for five previously described species, P. aegyptiacus, P. africana, P. beringamensis, P. calyptratus and P. perraldieri. Lastly, based on phylogenies and morphology of type material, we synonymized three reported species, P. algericus, P. arabicus, and P. rugospora with P. pistillaris, and described five newspecies that we named P. desolatus, P. inyoensis, P. mareebaensis, P. namaquensis, and P. namibensis.