Microchemical and molecular investigations reveal Pseudephebe species as cryptic with an environmentally modified morphology

The results of the first molecular phylogenetic study of Pseudephebe are presented; a three-locus phylogeny. The genus is confirmed as monophyletic within the alectorioid clade of Parmeliaceae. Two major clades were recovered, which can be assigned to the two traditional taxa, P. minuscula and P. pubescens, with modifications of the species delimitation, especially the variable P. minuscula. These species are cryptic and cannot be confidently distinguished morphologically due to phenotypic convergence. Therefore, the use of P. pubescens aggr. is recommended for samples not molecularly analyzed. Contrary to previous studies, specimens of both species might have indistinct pseudocyphellae and also contain lichen substances; norstictic acid was detected in c. 60% of specimens tested. An SSU 1516 Group I intron is usually present in P. minuscula but always absent in P. pubescens. The species-level nomenclature is summarized and sequenced reference specimens (RefSpec) for both Pseudephebe species are selected. Sequences from Bryoria mariensis established that this name was a synonym of P. minuscula.