Mendogia diffusa sp. nov. and an updated key to the species of Mendogia (Myriangiaceae, Dothideomycetes)

Abstract

Mendogia belongs to Dothideomycetes and its members are epiphytic on living bamboo culms or palms and distributed in tropical regions. Currently the genus comprises seven species. A further species of Mendogia was collected from the leaves of Fagales in Thailand. Morphological characteristics and multi-gene phylogenetic analyses using SSU, LSU and ITS sequences showed that the fungus is new to science, described herein as Mendogia diffusa. Mendogia diffusa is characterized by apothecial ascostromata, a carbonized epithecium, dark brown setae on the ascostromatal surface, hyaline paraphysoids, ovoid to clavate asci, and oblong to elliptical, muriform ascospores. The fungus has a dark pigmented surface, and is occasionally facultative, associated with patches of green algae, but not actually lichenized. Instead, the fungus penetrates the upper leaf surface, forming dark pigmented isodiametric cells below the epidermis. A re-examination of specimens of M. chiangraiensis, M. macrostroma and M. yunnanensis revealed the absence of algal association. In addition, Mendogia philippinensis (=M. calami) and M. bambusina (=Uleopeltis bambusina) were established based on morphological comparisons and previous studies. Comprehensive descriptions with phylogenetic analyses support M. diffusa as a novel species in Myriangiaceae. An updated key to the genus is provided.new species, morphology, phylogeny, saprobe, taxonomy

Keywords

• one new species
• morphology
• multilocus phylogeny