Endosporiaceae D. Pem, Doilom & K.D. Hyde, Myco- sphere 10(1): 1115–1246 (2019).

MycoBank number: MB  557066; Index Fungorum number: IF 557066; Facesoffungi number: FoF 06681, 2 species.

Pathogenic on bud of Populus tremuloides. Sexual morph: Undetermined. Asexual morph: Colonies (conidiomata) on PDA, OA and CA black, raised, cerebriform, comprising numerous cellular clumps in a thin covering, subcircular to irregular in outline, reverse black. Margin irregular with scarce, occasionally aggregated hyphae on PDA, even with adpressed or submerged hyphae on MEA. On PDA, cells more broad, swollen, subhyaline and dumbbell-shaped when two-celled, becoming multicellular by splitting in all directions, becoming darkly pigmented, irregular in shape, frequently separating into smaller clumps. Hyphae cylindrical or toruloid, light to dark brown, branched or unbranched, aerially determinate in growth, mostly elongated, hyaline at apex, forming muriform and darkly pigmented bodies. Endoconidia developing from the separation of adjacent daughter cells in cellular clumps through septum schizolysis, ellipsoidal to subglobose becoming broadly ellipsoidal to globose, hyaline, aseptate. Blastic conidia abundant in mature colonies, arising from cells of cellular clumps or seldom from sides of hyphae, cylindrical to ellipsoidal, regularly truncate at the base, sometimes globose, obovoid, fusiform, hyaline or light brown, aseptate.

Type: Endosporium Tsuneda.

Notes: Pem et al. (2019c) introduced Endosporiaceae to accommodate Endosporium. The family is characterized by cylindric hyphae, ellipsoidal, subglobose to globose endoconida and cellular clumps, globose, obovoid, fusiform blastic conidia. Endosporiaceae is unique in producing endoconidia from cellular clumps.