Melanconiellaceae Senan., Maharachch. & K.D. Hyde, Stud. Mycol. 86: 275 (2017)

MycoBank number: MB 821561; Index Fungorum number: IF 821561; Facesoffungi number: FoF 03495; 41 species.

Phytopathogenic or saprobic. Sexual morph: Stromata present or absent. If present; Pseudostromata inconspicuous, erumpent, pale or dark coloured ectostromatic disc or pulvillus causing a more or less pustulate bark surface. Ectostromatic disc convex, flat to concave which can be surrounded by bark or not. Central column beneath the disc is more or less conical, having hyaline or pigmented hyphae. The hyphae are mixed with a pigmented powdery amorphous substance in cream, yellow, olive, brownish or grey. Ascomata perithecial, epiphyllous without stromatic tissues and immersed in host substrate, inconspicuous or appearing as rounded bumps beneath the bark that surrounds the ectostromatic disc, oblique or horizontal, scattered or often arranged in a circle around the central column, with long lateral ostioles that converge at the margin of the central column. Ostioles emerging in various positions in the ectostromatic disc. Peridium bears dark, thick-walled cells of textura angularis. Paraphyses broad, hyaline or lacking. Asci 2–8- spored, unitunicate, cylindrical-clavate, oblong or fusoid, with a distinct, J-, apical ring, tapering below to a short, narrow pedicel. Ascospores 1–2- overlapping seriate, hyaline, yellowish or brown, oblong, fusoid or ellipsoid, 0–1-septate, septa central or slightly eccentric, slightly constricted or not, smooth-walled, with or without short, blunt appendages and sometimes with a narrow gelatinous sheath. Asexual morph: Coelomycetous. Conidiomata acervular or pycnidia, punctiform, subcuticular, immersed or erumpent, sometimes with a central, well-developed, pale brown, pseudoparenchymatous layer becoming thinner or absent at the margin of the conidiomata, multiloculate, sometimes papillate, sometimes with pale coloured, ectostromatic disc and central column or with radiate scutella. Scutella convex, membranous, brown, somewhat translucent, with a central hyaline or pale disc, giving rise to radiating hyphae, thick-walled cells radiating from a central point, rounded to pointed at the tips. Conidiophores often reduced to conidiogenous cells or branched, sometimes septate only at the base, few-celled, smooth, hyaline to pale brown, sometimes short, forming under the developing scutellum. Pseudoparaphyses filiform. Conidiogenous cells annellidic or phialidic. Conidia initially hyaline becoming brown, ellipsoid, obovoid, subglobose, ovoid or oblong, thick-walled, smooth to finely verrucose, with or without distinct hyaline sheath, each with a truncate base and obtuse to bluntly pointed apex, sometimes somewhat granular, sometimes with inconspicuous to conspicuous basal hilum, with or without distinct hyaline sheath or frill (adapted from Senanayake et al. 2017a).

Type genus – Melanconiella Sacc.

Notes – Senanayake et al. (2017a) revised the family to accommodate the genera Dicarpella (previously included in Melanconidaceae), Greeneria, Melanconiella, and Sphaeronaemella fragariae (was in Microascales incertae sedis), Tubakia (previously Diaporthales incertae sedis), and a novel genus Microascospora. These taxa formed a distinct clade with moderate support in the phylogenetic analysis and a new family was proposed.

Dicarpella was introduced based on D. bina and the asexual morph of this genus was reported as Tubakia (Belisario 1991). Tubakia is typified by T. japonica. It was found that the type species of these two genera are not linked. However, molecular data linked Tubakia and Diplacella coupled with a few Diplacella species having Tubakia asexual morphs (Sogonov et al. 2008). Tubakia is more commonly encountered than Dicarpella and is also a more widely used name than Dicarpella. Senanayake et al. (2017a) showed a plausible relationship of Dicarpella dryina and Tubakia seoraksanensis as a holomorphic genus. Senanayake et al. (2017a) mentioned without analysing sequence data of the type species that it is hard to confirm that Dicarpella and Tubakia are congeneric. Therefore, Senanayake et al. (2017a) maintained Dicarpella and Tubakia as two separate genera until further sequence data becomes available. Senanayake et al. (2017a) introduced a new genus Microascospora to this family with M. rubi as the type species. Sphaeronaemella fragariae did not cluster in this analysis with other Sphaeronaemella species and clustered with Microascospora rubi. Therefore, Sphaeronaemella fragariae was excluded from Sphaeronaemella and placed in Microascospora as M. fragariae. Senanayake et al. (2017a) therefore included Dicarpella, Greeneria, Melanconiella, Microascospora and Tubakia in Melanconiellaceae. Braun et al. (2018) revised Tubakia using morphological and molecular data. They sequenced the type species of Tubakia (T. dryina) and introduced a new family Tubakiaceae to accommodate Tubakia. Braun et al. (2018) considered Tubakia suttoniana and Dicarpella dryina as synonyms..

Senanayake et al. (2018) included Massariovalsa in Melanconiellaceae based on morphology, but Massariovalsa was not included in the phylogenetic analysis due to the lack of molecular data. Senanayake et al. (2018) therefore placed Greeneria, Massariovalsa, Melanconiella and Microascospora in Melanconiellaceae. In the phylogenetic analysis of Fan et al. (2018), Melanconiella cornuta formed a distinct clade basal to Melanconiella in the family. Based on morphology and various host affinities (Cornus and Juglans vs. Betulaceae), M. cornuta was excluded from Melanconiella by Fan et al. (2018) and placed in a new genus Sheathospora. Phookamsak et al. (2019) included Septomelanconiella as a new genus in Melanconiellaceae based on Septomelanconiella thailandica. Therefore, Melanconiellaceae presently accommodates the genera Dicarpella, Greeneria, Massariovalsa, Melanconiella, Microascospora, Septomelanconiella and Sheathospora.

Genera