Sydowia Bres., Hedwigia 34(Beibl.): (66) (1895).
MycoBank number: MB 5311; Index Fungorum number: IF 5311; Facesoffungi number: FoF 00093; 11 morphological species (Species Fungorum 2020), 4 species with molecular data.
Type species – Sydowia gregaria Bres., Hedwigia 34(Beibl.): (66) (1895).
Notes – Sydowia was transferred to Dothioraceae by Luttrell (1973) mainly based on its phragmosprous ascospores. von Arx & Müller (1975) placed this genus in Dothideaceae based on morphology, unilocular stromata and ascospores with transverse septa (Thambugala et al. 2014a). Multi-gene phylogenetic analyses based on S. polyspora (Schoch et al. 2006) placed Sydowia in Dothioraceae. However, Thambugala et al. (2014a) accommodated Sydowia in Dothideaceae pending molecular data for the type species. Sydowia eucalypti (Sphaerulina eucalypti) was introduced by Crous et al. (2003b) with its coniothyrium-like and hormonema-like synasexual morphs and Selenophoma asexual state in culture. Following a phylogenetic study, Thambugala et al. (2014a) introduced a new genus, Pseudosydowia to accommodate Sydowia eucalypti in Saccotheciaceae, Dothideales. Hormonema dematioides has been suggested as the asexual morph of S. polyspora (Butin 1964, Cheewangkoon et al. 2009, Thambugala et al. 2014a). Bills et al. (2004) showed S. polyspora and H. dematioides clustered in the same clade in their phylogeny analysis. In our multi-gene analysis, we confirmed the observations by Bills et al. (2004).