Notes: Phoma commelinicola (basionym: Phyllosticta commelinicola) was originally reported from Commelina nudiflora in Puerto Rico, with conidia measuring 9.6–14.4 × 4.8–7.2 μm (Young 1915). The isolate CBS 100409 was collected from Tradescantia sp., the same host family as Phoma commelinicola (Commelinaceae), and therefore it was initially identified as “Phoma commelinicola” (De Gruyter 2002). However, its conidia [(10.5–)13–17(–21) × (4–)5–6.5 μm] were found to differ from the original description of Phoma commelinicola. Phylogenetically, CBS 100409 formed a distinct lineage, separated from all genera previously described in Didymellaceae. Thus, a new genus and species, Macroascochyta grandis, was introduced to accommodate this isolate.