Notes: Although we assume that Phacidiopycnis is the asexual morph of Potebniamyces, the type species of Phacidiopycnis, P. malorum, still needs to be recollected to confirm this assumption. For this reason the synonymy between these two generic names remains unconfirmed. If shown to be synonymous, the older name, Phacidiopycnis, will have preference for the holomorph (Johnston et al. 2014). Potebniamyces produces black, gelatinous discs, erumpent from submerged stromata in tree bark. Although DiCosmo et al. (1984) considered this genus a possible member of Phacidiaceae, Rhytismataceae or Dermateaceae, it appears to be a member of an independent family. As the majority of the families in Helotiales still lack molecular data, we consider it premature to introduce any new family name here to accommodate Potebniamyces. DiCosmo et al. (1984) discussed the morphological differences between Potebniamyces and Phacidium, and Wang et al. (2006b) suggested a possible sister relationship between the two genera.