Melanomma Nitschke ex Fuckel, Jb. nassau. Ver. Naturk. 23-24: 159 (1870).
Saprobic or parasitic on wood and bark in terrestrial habitats. Sexual morph: Ascomata gregarious, immersed, erumpent to nearly superficial, globose to subglobose, broadly or narrowly conical, often laterally flattened, black, coriaceous, ostiolate. Ostiole single, central, papillate, often somewhat puckered or sulcate. Peridium comprising of two layers, outer layer comprising, small, heavily pigmented, thick-walled cells of textura angularis and inner layer comprising lightly pigmented to hyaline, thin-walled cells of textura angularis. Hamathecium of dense, thickened, filamentous, septate, trabeculate pseudoparaphyses, branching and rarely anastomosing above the asci. Asci 8-spored, bitunicate, fissitunicate, cylindrical to fusoid, with a short pedicel, apically rounded with an ocular chamber. Ascospores uniseriate and partially overlapping, pale brown to brown, broadly fusoid to fusoid, rounded at both ends, straight or slightly curved, 3- septate, constricted at the septa, the second cell from the apex slightly wider than the others, smooth-walled. Asexual morph: Coelomycetous. Conidiomata pycnidial, superficial, globose, black, ostiolate, circular, central. Mycelium immersed, branched, septate, brown. Pycnidial wall comprising two layers, outer thick-walled brown cells of textura angularis and inner layer comprising thin-walled hyaline cell of irregular issue. Conidiophores hyaline, septate, cylindrical, formed from the inner cells at base of the pycnidial wall. Conidiogenous cells enteroblastic, phialidic, hyaline, smooth. Conidia hyaline, aseptate, thin-walled, eguttulate, cylindrical or ellipsoidal, smooth-walled (Adapted from Sutton 1980 and Tian et al. 2015).
Type species: Melanomma pulvis-pyrius (Pers.) Fuckel
Notes: Melanomma was introduced by Fuckel (1870) with M. pulvis-pyrius as type species. Melanomma is characterized by erumpent to nearly superficial, globose to subglobose ascomata, cylindrical to fusoid, short pedicellate asci, broadly fusoid to fusoid ascospores. The asexual morph is characterized by pycnidial, superficial, globose conidiomata, hyaline, septate, cylindrical conidiophores, enteroblastic, phialidic, hyaline, smooth conidiogenous cells and hyaline, aseptate, thin-walled, eguttulate, cylindrical or ellipsoidal, smooth-walled conidia. The morphological concept of Melanomma by Fuckel (1870) was ‘small, carbonaceous ascomata having hyaline or brown, 2–3-septate ascospores (Chesters 1938; Fuckel 1870). Saccardo (1878, p. 344) emended the concept of Melanomma as “Spores ovate or oblong, multi-septate, colored.” Afterwards, Saccardo (1883, p. 98) broadened the concept of Melanomma as “perithecia gregarious, seldom scattered, fairly superficial, spherical, papillate or blunt, carbonaceous, smooth or slightly hairy. Asci elongate, mostly accompanied by paraphyses, 8-spored”. Barr (1990) chose Melanomma pulvis-pyrius as the lectotype species, gave a detailed circumscription for Melanomma and accepted 20 species (Kirk et al. 2001). The main morphological diagnostic character of Melanomma is the trabeculate pseudoparaphyses (Sivanesan 1984; Barr 1990a; Liew et al. 2000; Kirk et al. 2001). Zhang et al. (2008) re-studied the neotype of M. pulvis-pyrius, and additionally collected several specimens of M. pulvis-pyrius. Zhang et al. (2008) provided an ex-epitype culture (IFRDCC 2044) for M. pulvis-pyrius and reported that the epitype differs from the neotype in having thicker peridium. In the phylogenetic analysis of Zhang et al. (2008), Mugambi and Huhndorf (2009), Zhang et al. (2012) and Hyde et al. (2013) based on LSU, SSU, RPB2 and TEF1, Melanomma pulvis-pyrius forms a well-supported distinct lineage in Melanommataceae. Zhang et al. (2012) mentioned that the Melanomma concept based on ascospore morphology seems polyphyletic. Kirk et al. (2015) listed 299 epithets in Melanomma. Anamorphs reported for Melanomma are Aposphaeria, Nigrolentilocus, Phoma-like and Pseudospiropes (Chesters 1938; Sivanesan 1984; Hyde et al. 2011; Tian et al. 2015). Melanomma is morphologically and phylogenetically a distinct and type genus of Melanommataceae.