Elsinoaceae Höhn. ex Sacc. & Trotter, Syll. fung. (Abellini) 22: 584 (1913).
MycoBank number: MB 82022; Index Fungorum number: IF 82022; Facesoffungi number: FoF 05764, 200 species.
Parasitic or saprotrophic on plant leaves and fruits causing scab and sunken scab-like blemishes. Sexual morph: Pseudoascostromata usually spread around host veins, solitary, aggregated, or gregarious, wart-like or scab-like blemishes, pulvinate, superficial, globose to subglobose, white, pale yellow to brown, multi-loculate, locules scattered in upper part of pseudoascostromata. Cells of pseudoascostromata comprising host cells and inter dispersed light coloured fungal hyphae, opening by unordered break down of the surface layer. Locules with 3–10 asci inside each locule, ostiolate. Ostioles minute. Hamathecium lacking pseudoparaphyses. Asci 8- spored, bitunicate, fissitunicate, saccate to globose, with a minute pedicel, and indistinct ocular chamber. Ascospores irregularly arranged, oblong or fusiform with slightly acute ends, hyaline, 2–3 transverse septa, smooth-walled, lacking a sheath. Asexual morph: Coelomycetous “Sphaceloma”. Lesions circular, dark brown raised margin, cream-brown. Acervuli subepidermal, pseudoparenchymatous. Conidiophores hyaline to pale-brown, polyphialidic. Conidiogenous cells formed directly from the upper cells of the pseudoparenchyma, monophialidic to polyphidalic, integrated or discrete, determinate, hyaline to pale brown, lacking a thickened region around the phialide channel. Conidia ellipsoidal, hyaline, unicellular, aseptate, biguttulate.
Type – Elsinoe Racib.
Notes – Höhnel (1909a) invalidly introduced “Elsinoëen” based on habitat and development studies. Saccardo & Trotter (1913) proposed Elsinoaceae, and many studies placed this family in synonymy with Myriangiaceae (Jayawardena et al. 2014) based on pulvinate immersed or erumpent irregular pseudoascostromata and being restricted to foliar pathogens. Elsinoaceae has also been referred as Plectodiscellaceae a family established by Woronichin (1914) based on a single species
Plectodiscella piri, which he found on the leaves of apples and pear. However, based on observations of their restricted hosts, Barr (1979a, 1987b) and Eriksson (1981) suggested that Elsinoaceae should be treated as a separate family within Myriangiales. Phylogenetic evidence to support this theory was provided by Schoch et al. (2006, 2009a), Boehm et al. (2009a), Hyde et al. (2013) and Jayawardena et al. (2014). Lumbsch & Huhndorf (2010) included ten genera in Elsinoaceae. Jayawardena et al. (2014) revised this family based on morphology, accepting only two genera, Elsinoe and Molleriella.
Although, Index Fungorum (2020) included Beelia in Elsinoaceae, we retain its position in Chaetothyriaceae based on its asci with a very clear ocular chamber, and hyaline to straw-coloured ascospores, with a narrow mucilage sheath. In Elsinoaceae, they have pseudoascostromata with clear locules, 3–10 asci, with indistinct/minute ocular chambers, and hyaline spores, without mucilage sheath. Li et al. (2011) mentioned that Beelia is similar to Ainsworthia/Phaeosaccardinula rather than Elsinoe.