Mucomycosphaerella Quaedvl. & Crous, Persoonia 33: 22 (2014)

Index Fungorum number: IF 807791; MycoBank number: MB 807791; Facesoffungi number: FoF 09726

Etymology – Resembling the genus Mycosphaerella, except ascospores have mucoid sheaths.

Foliicolous. Ascomata pseudothecial, depressed ellipsoidal, immersed becoming erumpent, with central ostiole lacking periphyses, brown, dark brown at the ostiole, solitary or in clusters of two or more joined together; wall of textura angularis, consisting of 4–6 layers at the top, but only 2–3 layers at the sides and bottom. Hamathecium sparse, composed of branched and anastomosing septate pseudoparaphyses embedded in a gelatinous matrix. Asci ellipsoidal to ovoid, 8-spored, indistinctly pedicellate, bitunicate, fissitunicate, thick-walled, with a thin, tough ectotunica and a thick gelatinous, expanding endotunica. Ascospores bi- to triseriate, elongate ellipsoidal, sometimes inequilateral, 1-septate, with one additional pseudoseptum in each cell, slightly constricted at the septum, hyaline, guttulate, surrounded by a gelatinous sheath that is constricted around the septum.

Type species – Mucomycosphaerella eurypotami (Kohlm., Volkm.-Kohlm. & O.E. Erikss.) Quaedvlieg & Crous.

Notes — Mucomycosphaerella is distinguished from Mycosphaerella s.str. by having well-developed, persistent mucoid sheaths around its ascospores and the absence of Ramularia asexual states. Its ascomata are depressed and have a pale, thin-walled lower half and a hamathecium of loosely branched, anastomosing hyphae in a hymenial gel with hyaline ascospores (Kohlmeyer et al. 1999).