Species of Ceratocystis represent a group of important plant pathogens as well as saprobes that occur, primarily on woody substrates. The number of species in Ceratocystis has increased substantially in recent years, particularly as
DNA-based methods have allowed for the recognition of cryptic taxa. The aim of this study was to identify isolates of a Ceratocystis sp. collected from freshly cut stumps of Eucalyptus trees in Venezuela. This was carried out using morphological comparisons with similar fungi as well as DNA sequence comparisons for the Internal Transcribed Spacer regions 1 and 2 including the 5.8S rDNA operon, part of the Beta-tubulin gene and part of the Transcription
Elongation Factor 1-alpha gene region. Characteristics of the fungus in culture and its morphology resembled most species in the C. fimbriata sensu lato species complex. Microscopically, the fungus was most similar to C. fimbriata sensu stricto. Based on phylogenetic analyses, it was distinct from other species of Ceratocystis sensu lato having C. manginecans as its closest relative. The Ceratocystis sp. from Eucalyptus in Venezuela clearly represents a distinct taxon for which the name C. fimbriatomima sp. nov. is provided.