Asteromella Pass. & Thüm., in Thümen, Mycoth. Univ., cent. 17: no. 1689 (1880)
Dothideomycetes, genera incertae sedis
Saprobic orparasitic on the host plant. Sexual morph: undetermined. Asexual morph: Conidiomata dark brown, pycnidial, solitary to gregarious, immersed, globose, unilocular. Ostiole circular, papillate, centrally located. Conidiomatal wall composed of thick-walled, brown to paler cells of textura angularis. Conidiophores arising from the innermost layer of conidiomata, hyaline, cylindrical, branched at base, septate, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic, lageniform to subcylindrical, integrated or discrete, indeterminate, smooth walled, with periclinal thickenings at collarette zone. Conidia hyaline, cylindrical to oval, unicellular, smooth walled (Sutton 1980; Vanev and van der Aa 1998).
Type species: Asteromella ovata Thüm., Mycoth. Univ., cent. 17: no. 1689 (1880)
Notes: Asteromella species are generally regarded as the microconidial or spermogonial states of Mycosphaerella species (Vanev and Van Der Aa 1998; Crous 2009), but this connection has not been confirmed by molecular data. Ruszkiewicz-Michalska (2016) monographed Asteromella in Poland and detailed the history and generic concept of the genus. Asteromella is currently placed in Dothideomycetes genera incertae sedis (Wijayawardene et al. 2017b). More than 200 taxa of Asteromella are listed in Index Fungorum (2019) and MycoBank (2019), but many of them are illegitimate or invalid. Further studies with a larger number of collections and molecular data are needed to clarify the generic concept of Asteromella.
Distribution: Argentina, Austria, Australia, Belgium, Brazil, China (Taiwan), Costa Rica, Croatia, Czech Republic, Dominican Republic, Ecuador, Finland, France, Gabon, Germany, Greece, Hungary, India, Iran, Italy, Latvia, Malta, Netherlands, Philippines, Poland, Portugal, Russia, Serbia, Spain, Sweden, Switzerland, Tanzania, Turkey, UK, Ukraine, USA, Venezuela (Sutton 1980; Vanev and Van der Aa 1998; Ruszkiewicz-Michalska 2016).
Asteromella ovata (redrawn from Sutton 1980) a Vertical section of conidioma. b Conidia. c Conidiophores, conidiogenous cells and developing conidia.
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.