Ramularia Unger, Exanth. Pflanzen (Wien): 119 (1833).
= Mycosphaerella Johanson, Öfvers. K. Svensk. Vetensk.-Akad. Förhandl. 41(no. 9): 163 (1884) [1884-1885].
MycoBank number: MB 9691; Index Fungorum number: IF 9691; Facesoffungi number: FoF 09222; 1,662 morphological species (1,252 species as Mycosphaerella and 410 species as Ramularia) (Species Fungorum 2020), 154 species with molecular data (71 species as Mycosphaerella and 83 species as Ramularia).
Type species – Ramularia endophylla Verkley & U. Braun, in Verkley, Crous, Groenewald, Braun & Aptroot, Mycol. Res. 108(11): 1276 (2004).
≡ Sphaeria punctiformis Pers., Ann. Bot. (Usteri) 11: 26 (1794).
= Mycosphaerella punctiformis (Pers.) Starbäck, Bih. K. svenska VetenskAkad. Handl., Afd. 3 15(no. 2): 9 (1889).
Notes – Mycosphaerella was introduced by Johanson (1884) and is typified by M. punctiformis. The genus was introduced to accommodate many important pathogenic fungi characterizing by having tiny, black ascomata, immersed to semi-immersed, globose to subglobose, ostiolate, with papillate, thin-walled peridium of 1–3 layers, 8-spored, bitunicate, cylindrical to cylindric-obclavate, subsessile asci, lacking pseudoparaphyses, and hyaline, fusoid-ellipsoidal, 1- septate ascospores (Crous et al. 2009e, Hyde et al. 2013).
The asexual morph of Mycosphaerella has been linked to the hyphomycetous genus Ramularia which is characterized by solitary to fasciculate, hyaline conidiophores, distinct, thickened, darkened and refractive conidiogenous loci, and aseptate to transversely septate hyaline conidia with thickened, darkened, refractive scars, lacking appressoria (Verkley et al. 2004, Crous et al. 2009e, Videira et al. 2015b, 2016). Mycosphaerella and Ramularia are polyphyletic (Crous et al. 2007a, 2009e, Videira et al. 2015b, 2016). These two genera have a long historical discussion by many authors (Braun 1995, Crous et al. 2009c, e, Kirschner 2009, Videira et al. 2015b, 2016). Recently, many new genera were introduced to accommodate Mycosphaerella sensu lato and Ramularia sensu lata (Videira et al. 2016, 2017). Based on the agreement for naming of pleomorphic fungi in the International Code of Nomenclature for algae, fungi and plants, Mycosphaerella was treated as a synonym of Ramularia, the oldest name (Wingfield et al. 2012, Rossman et al. 2015, Videira et al. 2015b, 2016).