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

A dichotomous key to all currently accepted species of Hyphodontia in the broad sense is presented. It consists of a key to genera (Alutaceodontia, Botryodontia, Chaetoporellus, Deviodontia, Hastodontia, Hyphodontia s. str., Kneiffiella, Lagarobasidium, Lyomyces, Palifer, Rogersella, Schizopora, Xylodon) and detailed keys to species level within genera. The key also includes taxa which were published under preliminary names (such as ‘Hyphodontia species A’) and some taxa which require taxonomic clarification (like Hyphodontia macrescens). Some recently describes Hyphodontia species are placed in the keys to Palifer and Xylodon due to their morphology.

A study of corticioid fungi collections from Costa Rica, Panama, Colombia, and Ecuador has resulted in the identification of 26 morphospecies of Lyomyces. These distinctions were made based on characters such as basidiospore size and shape, cystidia morphology, basidioma texture, and hymenial surface configuration. Sequences of rDNA ITS were obtained for 12 of these species, and their relationships to previously known taxa were illustrated using Bayesian and Maximum Likelihood reconstructions of the phylogeny. Protologues are given for 10 new species of Lyomyces: L. boquetensis (found in Panama, belonging to L. sambuci group), L. granulosus (from Costa Rica and Panama, related to L. fimbriatus), L. napoensis (from Ecuador, related to L. elaeidicola), L. neocrustosus (from Panama, L. crustosus group), L. oleifer (from Ecuador, L. crustosus group), L. pantropicus (from Panama and Ecuador, related to L. microfasciculatus), L. orarius (from Ecuador, L. sambuci group), L. parvus (from Costa Rica and Ecuador, L. crustosus group), L. sceptrifer (from Ecuador, related to L. gatesiae), and L. subcylindricus (from Panama, L. crustosus group). Macro- and micro-morphology illustrations are provided for these new species. Additionally, the range of L. organensis is extended to Ecuador. Scanning electron microscopy of crystalline deposits in basidiomata has shown the differences in crystal size and aggregation manner between species.