Cancellidiaceae K.D. Hyde & Hongsanan, fam. nov.

MycoBank number: MB 557982; Index Fungorum number: IF 557982; Facesoffungi number: FoF 09413

Type genus: Cancellidium Tubaki

Saprobic on wood and twigs in freshwater habitats. Asexual morph: Colonies on natural substrates effuse, black, glistening, scattered. Mycelium mostly immersed, composed of branched, septate, smooth, thin‑walled, hyaline to pale brown hyphae. Conidiophores semimacronematous to macronematous, mononematous, pale brown to yellowish brown, smooth, thick‑walled, septate, cylindrical, sometimes developed from assimilative hypha. Conidiogenous cells monoblastic, integrated, terminal, pale brown to yellowish brown. Conidia acrogenous, holoblastic, solitary, dry, olivaceous to greyish green, shiny, flattened, obovate or ellipsoidal, fan‑shaped, mostly with truncated head, composed of many parallel, septate columns arranged in lines radiating from conidial base, internally contain chains of subhyaline, small moniliform cells. Sexual morph: Undetermined.

Notes: This family comprises a single genus, Cancellidium which is discussed under the order. The stem age of Cancellidiaceae is around 137 MYA (Fig. 3), which falls in the range of a family (Hyde et al. 2017).

Fig. 3 The accepted families and orders in Diaporthomycetidae with divergence time estimations are shown in the MCC tree