Marcelaria, a new genus for the Laurera purpurina group in the Trypetheliaceae (Ascomycota: Dothideomycetes)

Abstract

We describe the new genus Marcelaria Aptroot, Nelsen & Parnmen for the Laurera benguelensis group, a small lineage within Trypetheliaceae that is well-supported in molecular phylogenetic studies and features distinctive ascoma morphology. The genus is characterized by sessile, solitary to aggregate ascoma warts with broad, flat ostiolar region and often a split between the inner ascoma wall and the surrounding tissue. Three species are accepted in this genus, all previously placed in Laurera sensu lato: the neotropical and African M. purpurina (Nyl.) Aptroot, Nelsen & Parnmen, with bright red ascomata; the East Asian M. benguelensis (Müll. Arg.) Aptroot, Nelsen & Parnmen, with (orange-yellow) perithecia and an orange pruinose thallus, as well as inspersed hamathecium; and the East Asian M. cumingii (Mont.) Aptroot, Nelsen & Parnmen, with (orange-yellow) perithecia with a broad ostiolar region and a smooth, non-pruinose thallus, also with inspersed hamathecium. All three species are illustrated and a taxonomic key is given. The pigment chemistry of the species was clarified using comparative TLC analysis.