Gintarasia and Xalocoa, two new genera to accommodate temperate to subtropical species in the predominantly tropical Graphidaceae (Ostropales, Ascomycota)

Abstract

The phylogenetic placement of Chapsa lamellifera, C. megalophthalma and Diploschistes ocellatus was studied using a dataset of five genetic markers (mtSSU, nuLSU, RPB1, RPB2 and ITS). As extratropical species occurring in Australasia, C. lamellifera and C. megalophthalma differ from other species in that genus by having relatively large ascomata with muriform ascospores and complex chemistry of either the protocetraric or stictic acids chemosyndrome. D. ocellatus is unique within Diploschistes, in lacking lateral paraphyses and containing the norstictic acid chemosyndrome. Previous phylogenetic analysis gave inconclusive results regarding the phylogenetic position of these taxa, and hence in the present study, a larger sampling of molecular markers was employed. Our results demonstrated that the two Chapsa species and D. ocellatus are not part of their current genera. Consequently, the new genera Gintarasia Kraichak, Lücking & Lumbsch and Xalocoa Kraichak, Lücking & Lumbsch are described to accommodate these species. The new combinations Gintarasia lamellifera (Kantvilas & Vězda) Kraichak, Lücking & Lumbsch, G. lordhowensis (Mangold) Kraichak, Lücking & Lumbsch, G. megalophthalma (Müll. Arg.) Kraichak, Lücking & Lumbsch and Xalocoa ocellata (Vill.) Kraichak, Lücking & Lumbsch are also proposed.