Membranomyces (Clavulinaceae, Cantharellales) Jülich consists of two described species of resupinate (crust-like) basidiomycetes. Previous studies indicated that Membranomyces falls within the Clavulinaceae, but the phylogenetic position of the genus has not been fully resolved. Membranomyces species were thought to be saprotrophic until 2003 when Tedersoo et al. detected Membranomyces delectabilis on ectomycorrhizal roots of Populus and Picea. Membranomyces was previously known only from collections made in eastern Canada and Europe. We recently sequenced the ITS rDNA barcode region from Scandinavian herbarium specimens identified as M. delectabilis and Membranomyces spurius. Phylogenetic analyses of these sporocarp sequences and similar environmental sequences indicated that Membranomyces is more diverse than previously thought and forms ectomycorrhizas with hosts from a diverse range of plant families in many north temperate ecosystems.