Polyphialoseptoria Quaedvl., R.W. Barreto, Verkley & Crous, Stud. Mycol. 75: 355 (2013).
Foliicolous, plant pathogenic. Sexual morph: Unknown. Asexual morph: Conidiomata brown, erumpent, pycnidial (acervular in culture), globose, brown. Conidiomatal wall of 3–6 layers of pale brown cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth, subcylindrical to ampulliform, proliferating sympodially at apex, forming polyphialides with minute periclinal thickening, or as solitary loci on superficial mycelium in culture. Conidia hyaline, smooth, granular to guttulate, scolecosporous, irregularly curved, apex subobtuse, base long obconically truncate, transversely multi-euseptate, in older cultures disarticulating at septa; microcyclic conidiation also common in older cultures (adapted from Quaedvlieg et al. 2013).
Type species: Polyphialoseptoria terminaliae Quaedvl., R.W. Barreto, Verkley & Crous
Notes: Polyphialoseptoria is distinct from Septoria in conidial morphology. Polyphialoseptoria is a well-supported genus in Mycosphaerellaceae. Molecular markers available for Polyphialoseptoria include ITS, LSU, BTUB, RPB2 and TEF-1.