Multi-gene phylogeny and taxonomy of <i>Amauroderma</i> s. lat. (<i>Ganodermataceae</i>)

<i>Amauroderma</i> s.lat. has been defined mainly by the morphological features of non-truncate and double-walled basidiospores with a distinctly ornamented endospore wall. In this work, taxonomic and phylogenetic studies on species of <i>Amauroderma</i> s.lat. are carried out by morphological examination together with ultrastructural observations, and molecular phylogenetic analyses of multiple loci including the internal transcribed spacer regions (ITS), the large subunit of nuclear ribosomal RNA gene (nLSU), the largest subunit of RNA polymerase II (<i>RPB1</i>) and the second largest subunit of RNA polymerase II (<i>RPB2</i>), the translation elongation factor 1-α gene (<i>TEF</i>) and the β-tubulin gene (<i>TUB</i>). The results demonstrate that species of <i>Ganodermataceae</i> formed ten clades. Species previously placed in <i>Amauroderma</i> s.lat. are divided into four clades: <i>Amauroderma</i> s.str., <i>Foraminispora</i>, <i>Furtadoa</i> and a new genus <i>Sanguinoderma</i>. The classification of <i>Amauroderma</i> s.lat. is thus revised, six new species are described and illustrated, and eight new combinations are proposed. SEM micrographs of basidiospores of <i>Foraminispora</i> and <i>Sanguinoderma</i> are provided, and the importance of SEM in delimitation of taxa in this study is briefly discussed. Keys to species of <i>Amauroderma</i> s.str., <i>Foraminispora</i>, <i>Furtadoa</i>, and <i>Sanguinoderma</i> are also provided.