Phylogenetic and morphological studies in Xylodon (Hymenochaetales, Basidiomycota) with the addition of four new species

Abstract

<i>Xylodon</i> (Hymenochaetales, Basidiomycota) is the largest segregate genus of <i>Hyphodontia</i> s.l. Based on molecular and morphological data, 77 species are accepted in <i>Xylodon</i> to date. Phylogenetic analyses of ITS and 28S sequences, including 38 new ITS and 20 28S sequences of <i>Xylodon</i> species, revealed four species new to science. The new taxa <i>X.exilis</i>, <i>X.filicinus</i>, <i>X.follis</i> and <i>X.pseudolanatus</i> from Taiwan, Nepal, Réunion, Belize, and USA are described and illustrated. In addition, species concepts for <i>Odontiavesiculosa</i> from New Zealand and <i>Xylodonlanatus</i> from U.S.A. are revised and the new name <i>X.vesiculosus</i> is proposed. Phylogenetic analyses of the ITS region placed <i>X.spathulatus</i>, <i>X.bubalinus</i> and <i>X.chinensis</i> in a strongly supported clade and demonstrated that they are conspecific. <i>Palifer</i> and <i>Odontiopsis</i> are synonymised under <i>Xylodon</i> based on morphological and sequence data. The following new combinations are proposed: <i>X.erikssonii</i>, <i>X.gamundiae</i>, <i>X.hjortstamii</i>, <i>X.hyphodontinus</i>, <i>X.septocystidiatus</i> and <i>X.verecundus</i>. Line drawings of <i>X.cystidiatus</i>, <i>X.hyphodontinus</i>, <i>X.lanatus</i> and <i>X.vesiculosus</i>, as well as photographs of <i>X.raduloides</i> basidiomata, are provided. A key to <i>X.lanatus</i> and similar species is presented.