Polystomellina is a genus of fungi in the Microthyriaceae family; according to the 2007 Outline of Ascomycota, the placement in this family is uncertain. This is a monotypic genus, containing the single species Polystomellina didymopanacis.
- Lumbsch TH, Huhndorf SM. (December 2007). "Outline of Ascomycota – 2007". Myconet (The Field Museum, Department of Botany, Chicago, USA) 13: 1–58.