Knufia endospora, a species described previously on the basis of cultured material, was found forming distinctive sporodochia on the bark of balsam poplar. Phylogenetic analyses of this fungus and some allied species indicated that (i) it forms a monophyletic group with Knufia cryptophialidica (type species of Knufia) and with Coniosporium perforans, Coniosporium epidermidis and Phaeococcomyces chersonesos and (ii) P. chersonesos and Sarcinomyces petricola are conspecific. These Coniosporium and Phaeococcomyces species also shared major morphological characteristics with Knufia in culture and were morphologically and phylogenetically distant from the type species of their respective genera. The following new combinations are proposed: Knufia perforans (Sterflinger) Tsuneda, Hambleton & Currah; Knufia epidermidis (D.M. Li, de Hoog, Saunte & X.R. Chen) Tsuneda, Hambleton & Currah; and Knufia chersonesos (Bogom. & Minter) Tsuneda, Hambleton & Currah. Phaeococcomyces catenatus and Phaeococcomyces nigricans (type species of Phaeococcomyces) were morphologically similar but phylogenetically distant from each other and from Knufia.

An endoconidial, black meristematic taxon Atramixtia arboricola gen. et. sp. nov. (Dothideales) from the black subicula found on twigs of declining white spruce, Picea glauca (Moench) Voss, in Alberta is described. It is morphologically distinguishable from other endoconidial taxa by the conidioma composed of clumps of endoconidial conidiogenous cells, scattered meristematically dividing cells, dematiaceous hyphae, abundant brown, granular matrix materials, and sometimes plant tissue. Endoconidia also occur in conidiogenous cellular clumps that are not organized into a conidioma but develop directly from stromatic cells on the bark. In culture, it forms similar endoconidial conidiomata and also a mycelial, blastic synanamorph that superficially resembles Hormonema . Atramixtia arboricola is a member of the Dothideales and shows phylogenetic affinities to a clade of conifer-stem and -needle pathogens, including Sydowia and Delphinella , although no teleomorph was found either on the natural substrate or in culture. It has not been determined whether A. arboricola is pathogenic to its host, but the occurrence of abundant intracellular hyphae in the host periderm suggests that the fungus is at least parasitic.