This study did not support the taxonomic framework of Simmons (2007) where A. alternata, Alternaria tenuissima, and Alternaria mali are considered distinct taxa. This supports findings in the citrus pathosystem, where two evolutionary lineages contained ten morphologically described species ( Stewart et al. 2014). The morphologically described A. tenuissima and A. mali species in Simmons (2007) possess very similar morphological characters including overlapping ranges of spore characters and produce similar chains of spores. These results indicate that A. mali is a re-description of the morphological species A. tenuissima. Isolates possessing an A. alternata-like morphology have been described as rare in the environment ( Simmons and Roberts, 1993 and Simmons, 1999) and it has been suggested that most identifications of A. alternata are in fact misidentifications of A. tenuissima Simmons (2007). It may be the case that A. alternata does not represent a distinct taxon within the A. alternata species group but instead represents a combination of morphological characters possible within those possible in a single A. tenuissima lineage.