Ectodidymella L.W. Hou, L. Cai & Crous, in Hou, Groenewald, Pfenning, Yarden, Crous & Cai, Stud. Mycol. 96: 340 (2020)

Index Fungorum number: IF 833506; MycoBank number: MB 833506; Facesoffungi number: FoF 11506

Etymology – From the Greek εκτοs, outside, because it is phylogenetically distant from Didymella.

Asexual morph Conidiomata pycnidial, scattered, globose, depressed globose, black, large, usually with a conspicuous neck. Pycnidial wall thick, pseudoparenchymatous, outer layers slightly pigmented. Conidiogenous cells phialidic, hyaline, smooth, ampulliform to doliiform, with minute periclinal thickening. Conidia oblong to subcylindrical, eguttulate or with a small guttule at each end. Sexual morph Ascomata pseudothecial, only recorded in one species in vivo, erumpent, globose to irregular-shaped, solitary or confluent, scattered or aggregated, ostiolate, with a small papilla-shaped ostioles, lacking setae. Pseudothecial wall rough, multi-layered, composed of pseudoparenchymatous cells, outer layers pig- mented, black-brown. Asci narrow, cylindrical to clavate, 4– 8- spored, coarse and thick-walled. Pseudoparaphyses scanty and atypical, coarse, branched. Ascospores hyaline, biseriate, elongated clavate to fusiform, uniseptate, slightly or barely constricted at the septum, upper cell slightly wider than the lower cell (Petrak 1928).

Type species – Ectodidymella nigrificans (P. Karst.) L.W. Hou et al.

Notes – Ectodidymella is typified by Phoma nigrificans. The sexual morph of Phoma nigrificans (Didymella macropodii) is morphologically similar with species of Didymella. However, phylogenetically it forms a distinct clade that is distant from Didymella and separated from all genera previously described in Didymellaceae. Morphologically, Ectodidymella differs from Didymella by occasionally producing four ascospores in a single ascus, which is rare in Didymellaceae.