XVI International Botanical Congess

Crepidotus (Agaricales) consists of small, saprophytic fungi, with a pleurotoid habit. Several conflicting infrageneric classifications have been proposed. Using nuclear large subunit ribosomal DNA sequences, phylogenetic relationships between 35 morphologically diverse species of Crepidotus were analyzed in conjunction with other generic representatives of the Crepidotaceae. None of the previously proposed classification systems reflect the relationships found in this study. However, the system of Hesler and Smith is broadly useful for diagnosing monophyletic groupings of Crepidotus taxa at the section level. Morphological characters traditionally applied for infrageneric classification appear to be homoplasic. Less commonly emphasized characters are discussed that may be indicative of monophyletic clades.