Three Cryptosporiopsis species have thus far been isolated from roots of woody plants. A fourth species, which was recently isolated from roots of Calluna vulgaris, Erica tetralix, Vaccinium vitis-idaea, and V. myrtillus in The Netherlands, is described here as new. Sporulation on the natural substratum has not been observed and the morphological description of this fungus is therefore based on characters expressed on oatmeal and malt extract agars. The phenotypic characters indicated a close relationship with the other root-inhabiting species of Cryptosporiopsis and species of the associated teleomorph genus Pezicula. This relationship was confirmed by phylogenetic analyses using sequence data of the 5.8S nuclear rDNA and flanking internal transcribed spacers. In order to facilitate recognition of this possibly under-recognized category of root inhabitants, a key to the root-inhabiting Cryptosporiopsis species based on characters in vitro is given.