Aposphaeria Sacc., Michelia 2(no. 6): 4 (1880).
Index Fungorum number: IF 7198; MycoBank number: MB 7198; Facesoffungi number: FoF 00756; 84 morphological species (Species Fungorum 2020), 2 species with molecular data.
Saprobic on the host plant in terrestrial habitat. Sexual morph: see Tibpromma et al. (2017). Asexual morph: Conidiomata black, stromatic, pycnidial, solitary to gregarious or confluent, immersed to semi-immersed to superficial, globose to subglobose, unilocular or multilocular, glabrous, ostiolate. Ostiole circular, centrally located. Conidiomatal wall composed of thick-walled, dark brown to hyaline cells of textura angularis. Conidiophores arising from the inner cavity of the conidiomata, hyaline, cylindrical, branched at the base, septate, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic, cylindrical, integrated or discrete, determinate, smooth-walled, with terminal or lateral apertures. Conidia hyaline, cylindrical to ellipsoidal, unicellular, smooth, guttulate (Sutton 1980).
Type species – Aposphaeria pulviscula (Sacc.) Sacc., Michelia 2(no. 6): 4 (1880).
≡ Phoma pulviscula Sacc., Michelia 1(no. 2): 259 (1878).
Notes – Sutton (1980) and Tian et al. (2015) described and illustrated the generic type of Aposphaeria. More than 200 taxa are included in Aposphaeria, but most of them have not been re-studied (Sutton 1980). De Gruyter et al. (2013) showed that Aposphaeria was phylogenetically related to Melanommataceae, and Tian et al. (2015) accepted Aposphaeria as a separate genus in this family. Hashimoto et al. (2017) re-circumscribed Melanommataceae and accepted Melanomma Nitschke ex Fuckel sensu stricto in the family; Aposphaeria and other genera accepted by Tian et al. (2015) however, were placed in Pleosporales incertae sedis. However, Wanasinghe et al. (2018) adopted a broad concept as did Tian et al. (2015) and included Aposphaeria in the Melanommataceae. Aposphaeria is characterized by pycnidial, unilocular conidiomata, short, cylindrical, branched conidiophores and hyaline, aseptate, cylindrical or ellipsoidal conidia (Tian et al. 2015). Some Aposphaeria species have been synonymized in other different genera, such as Chaetomastia, Massariosphaeria, Melanomma, Mytilinidion and Rhytidhysteron (Sivanesan 1984, Tanaka & Harada 2004, de Gruyter et al. 2013, Zhang et al. 2012b, Hyde et al. 2013, Tian et al. 2015). There is no molecular data for the type species, and Tian et al. (2015) suggested to retain Aposphaeria as a genus in Melanommataceae.
Distribution – Australia, France, Germany, India, Italy, Morocco, Netherlands, Norway, Pakistan, Portugal, Russia, Slovenia, Spain, South Africa, Sweden, Thailand, UK, USA
(De Gruyter et al. 2013; Li et al. 2016, this study, https://
www.gbif.org/)