Palawaniaceae fam. nov., a new family (Dothideomycetes, Ascomycota) to accommodate Palawania species and their evolutionary time estimates

Palawania species are common on palms, occurring on dried fronds and spines, rarely on leaves, at first appearing as solitary, circular, black spots and then being confluent and lacking superficial hyphae. The taxonomy of the genus has been problematic because of lack of some important morphological characters as well as molecular data. Two collections made in Thailand are characterized based on analyses of combined LSU, SSU and RPB2 sequence datasets. Phylogenetic analyses indicate that Palawania species form a sister clade with Pleurotremataceae (= Dyfrolomycetaceae) and have a close relationship with Muyocopronales and Acrospermales. Thus, we introduce a new family Palawaniaceae (Dothideomycetes family, incertae sedis). A new Palawania species is also introduced from northern Thailand based on its distinct phylogeny and comparison of morphological characteristics. The present study clarifies the phylogenetic placement of Palawania and divergence time estimates are provided for the new family.