A phylogenetic revision of Penicillium sect. Exilicaulis, including nine new species from fynbos in South Africa

A survey of the fynbos biome in South Africa resulted in the isolation of 61 Penicillium species from Protea repens infructescences, air, and soil samples. Fourteen of these belong to Penicillium sect. Exilicaulis and therefore we considered it an opportunity to re-evaluate the taxonomy of the section. Phylogenetic comparisons of the ITS, β-tubulin, calmodulin and RPB2 gene regions of the 76 section Exilicaulis species, revealed 52 distinct species, including nine new species from fynbos. Morphological comparisons confirmed the novelty for most of these, however, new species closely related to P. rubefaciens did not show significant or consistent morphological differences and we thus placed a bias on phylogenetic data applying the Genealogical Concordance Phylogenetic Species Recognition (GCPSR) concept. In this paper we describe the nine new species and update the accepted species list and resolve synonyms in the section. Importantly, we reveal that P. citreosulfuratum is the correct name for the clade previously considered to represent P. toxicarium fide Serra et al. (2008). The nine new species are: Penicillium atrolazulinum, P. consobrinum, P. cravenianum, P. hemitrachum, P. pagulum, P. repensicola, P. momoii, P. subturcoseum, and P. xanthomelinii spp. nov.