Xenopenidiella Quaedvl. & Crous, in Quaedvlieg et al., Persoonia 33: 33 (2014).
Index Fungorum number: IF 807845; Facesoffungi number: FoF 07043, 7 morphological species (Species Fungorum 2021), 7 species with molecular data.
Saprobic on leaf litter. Sexual morph: Unknown. Asexual morph: Mycelium consisting of strongly branched, septate, smooth or almost so, pale olivaceous to medium brown, guttulate, commonly constricted at septa, 2–6 µm wide hyphae, swollen cells up to 8 µm wide, wall up to 1(–1.5) µm wide. Conidiophores dimorphic. Macronematous conidiophores separate, erect, subcylindrical, predominantly straight to slightly curved, terminally loosely penicillate which is neither lobed nor swollen, and lacks rhizoids, up to 10-septate, medium to dark brown, wall up to 1(–1.5) µm wide. Micronematous conidiophores erect, subcylindrical 1–3-septate, pale to medium brown (concolorous with hyphae). Conidiogenous cells predominantly terminal, rarely intercalary, medium brown, smooth, subcylindrical, but frequently swollen at apex, loci (predominantly single in micronematous conidiophores, but up to 4 in macronematous conidiophores) flat tipped, sub-denticulate or not, 1–1.5 µm wide, barely to slightly darkened and thickened-refractive. Conidia in branched chains, medium brown, verruculose, (appearing like small spines under light microscope), ellipsoid to cylindrical-oblong, up to 1(–1.5) µm wide, frequently constricted at septa, which turn dark with age; ramoconidia 1(–3)-septate; secondary conidia, hila unthickened to very slightly thickened and darkened, not refractive (adapted from Crous et al. 2007).
Type species: Xenopenidiella rigidophora (Crous, R.F. Castañeda & U. Braun) Quaedvl. & Crous
Notes: Xenopenidiella is characterised by medium brown, smooth conidiogenous cells barely to slightly darkened and thickened-refractive producing medium brown, verruculose conidia. Xenopenidiella resembles Penidiella but can be differentiated based on DNA sequence data. Xenopenidiella is a distinct genus in Teratosphaeriaceae. Molecular markers available for Xenopenidiella are ITS, LSU, BTUB, Calmodulin and TEF-1.