Abstract
Paratrichaptum accuratum is a large conspicuous polypore fungus growing on dead or living angiosperm trees in subtropical-boreal areas of China, Indonesia, Japan, and Taiwan. The present study places P. accuratum in the family Gloeophyllaceae that belongs to the order Gloeophyllales within Agaricomycetes (Basidiomycota), based on evidence derived from morphological and ecological characteristics, and phylogenetic analyses of sequences of nuclear rDNA regions (5.8S, nuc 18S, nuc 28S) and protein-coding genes (rpb1, rpb2, and tef1). The analyses presented in this study also give strong support for including Jaapia in Gloeophyllaceae and Gloeophyllales. Thus, the names Jaapiaceae and Jaapiales are considered here as synonyms of Gloeophyllaceae and Gloeophyllales. Since Paratrichaptum represents the earliest diverging lineage in Gloeophyllales, pileate basidiocarps and brown rot appear to be ancestral states of Gloeophyllales. Paratrichaptum accuratum may represent a relic species, according to its phylogenetic position, peculiar distribution pattern and rare occurrence.