Digitosarcinella S. Hughes, Can. J. Bot. 62(11): 2208 (1984).
Index Fungorum number: IF 11070; Facesoffungi number: FoF 08928, 1 morphological species (Species Fungorum 2022), no molecular data available.
Saprobic on leaves. Sexual morph: Unknown. Asexual morph: Colonies foliicolous, mostly on upper surface, effuse, dark brown to black. Mycelium closely appressed to leaf surface, composed of a radiating network of straight to sinuous, pale brown to dark brown, smooth or roughened, hyphopodiate hyphae. Secondary hyphae may be closely compacted; hyphae on the upper surface of leaves tend to be straighter than those on the under surface. Hyphopodia concolorous with hyphae, usually sessile, rarely terminal on a short lateral projection, frequently unilateral with several on the right and then on the left, sometimes alternate, irregularly subglobose to mostly broadly obpyriform. Hyphopodia sometimes produce a short hypha which arches around and is closely appressed to the hyphopodium; the curved hypha may cease its terminal growth and bear a lateral hypha or conidiophore, or it may continue its growth over the leaf surface. Synasexual morph: Conidiogenous cells scattered, arising centrifugally, sessile, lateral, concolorous with hyphae, subcylindrical to broadly ellipsoidal, monoblastic. Conidium initials terminal, subglobose and lobed, soon becoming (2-)4-3-7) celled usually in one plane; brown to dark brown pigmentation deveIops early, initials are deeply constricted at the septa, and the outer walls are thick and usually bear low rounded protuberances. The walls proliferate toward the point of attachment of the initial to produce a cheiroid conidium with parallel, straight or curved, (2-)4-5(-7) closely appressed arms up to 7-septate and constricted at the septa, at the distal (initial) end, tapering gradually toward the paler proximal (growing) end which is hyaline to subhyaline. The paler, proximal cells of conidia are thin-walled and mostly collapsed, but a few attached conidia indicate that the attached arm extends by intercalary growth. The compound conidia are more or less oblong at maturity, and distally progressively thicker walled; the septa usually show a conspicuous central pore. Circular, hyaline, thin-walled areas, on minute projections, one to a cell and in linear series, have been seen on the arms of some conidia. Hyaline to very pale brown hyphae have been seen to have arisen from the thin areas and presumably represent germination (adapted from Hughes 1984).
Type species: Digitosarcinella caseariae S. Hughes
Notes: Digitosarcinella is characterised by foliicolous colonies, concolorous hyphopodia with a lateral hypha or conidiophore, or it may continue its growth over the leaf surface. The synasexual morph is characterised by subcylindrical to broadly ellipsoidal, monoblastic conidiogenous cells, and subglobose and lobed conidium. Digitosarcinella is currently a distinct genus in Englerulaceae but more fresh collections are needed to confirm the correct taxonomic placement of the genus.