Myrtapenidiella Quaedvl. & Crous, in Quaedvlieg et al., Persoonia 33: 26 (2014).
Foliicolous, saprobic on host. Sexual morph: Unknown. Asexual morph: Mycelium consisting of branched, septate, smooth to slightly verruculose or warty, pale to dark brown hyphae. Conidiophores dimorphic. Microconidiophores reduced to conidiogenous cells, lateral on hyphae, with or without a basal septum. Macroconidiophores erect, arising as lateral branches from superficial hyphae, or as terminal ends of creeping hyphae, variable in length, pale to dark brown, smooth to finely verruculose. Conidiogenous cells terminal, rarely intercalary, cylindrical, tapering to a flattened apical region, finely verruculose, medium brown, paler toward the apex, with up to two conidiogenous loci, often apical, sometimes situated on small lateral shoulders, loci truncate, not denticulate; scars slightly thickened, darkened, visible as small dark circles when viewed directly from above. Ramoconidia subcylindrical or obovoid, 0–3-septate, base sub truncate to slightly rounded, but not coronate, pale to medium brown, finely verruculose, slightly thick-walled; hila thickened and darkened. Conidia in branched acropetal chains, broadly fusiform to obovoid or subcylindrical, 0–1-septate, pale to medium brown; wing-like mucoid sheaths present in some species. Chlamydospores globose to subovoid, dark brown, thin-walled, terminal or intercalary, mostly 1-celled, rarely septate, produced from narrow hyphae (adapted from Quaedvlieg et al. 2014).
Type species: Myrtapenidiella tenuiramis (Crous & Summerell) Quaedvl. & Crous
Notes: Myrtapenidiella differs from Penidiella in having dimorphic conidiophores with irregular branching patterns, septate ramoconidia, with hila that are slightly thickened and darkened. Some species are also characterised by chlamydospores and have wing-like mucoid sheaths on conidia. Myrtapenidiella is a well-supported genus in Teratosphaeriaceae. Molecular markers available include LSU, ITS, Actin, BTUB, Calmodulin, RPB2 and TEF-1.