Gnomoniaceae G. Winter, Rabenh. Krypt.-Fl., Edn 2 (Leipzig) 1.2: 570 (1886)

Index Fungorum number: IF80810; 485 species.

Saprobic on bark and leaves of overwintered plants. Sexual morph: Stromata lacking, or poorly to well-developed, scattered, erumpent, pustuliform with one or rarely two ascomata or valsoid, broadly elliptic to rounded, large. Ectostromata well-developed, brown to black, thick ectostromatic disc at perithecial necks. Ascomata immersed to erumpent, solitary or aggregated, globose to subglobose, black, coriaceous, thin-walled, with one or more long, central or eccentric necks with hyaline periphyses. Peridium comprising few layers of brown, thick-walled cells of textura angularis. Paraphyses few, hyaline, septate, cellular. Asci 8–32-spored, unitunicate, oval, fusiform to almost filiform, short pedicellate, with a distinct, J-, apical ring. Ascospores biseriate, overlapping uniseriate to fasciculate, hyaline, oval, fusiform, ovoid to subulate, small, unicellular to 1-septate, rarely multiseptate, ends mostly rounded, rarely pointed, appendages absent or subulate, navicular or whip-shaped, smooth-walled. Asexual morph: Coelomycetous. Conidiomata acervuli or pycnidial, subcuticular, papillate or not, oblate to globose, black, thick-walled, with one chamber containing whitish conidial mass. Conidiophores simple, filiform to fusiform, annellations visible or invisible, densely branched. Conidiogenous cells usually phialidic, rarely with a few annellidic scars, irregular in shape, lageniform to cylindrical, gradually tapering to ends for one quarter to three quarters of their length, or abruptly narrowing to long neck at about half of the phialide length, or abruptly narrowing at apex, straight or curved, sometimes asymmetric swollen nodes, proliferating into other conidiogenous cells at basal or middle part. Conidia broadly ellipsoid to oval, sometimes obovoid, allantoid, occasionally curved or sinuate to slightly angular, hyaline, often unicellular (adapted from Senanayake et al. 2018).

Type genus – Gnomonia Ces. & De Not.

Notes – Gnomoniaceae was introduced to accommodate fungal species having upright perithecia with or without long or short neck and presence or absence of stromatic tissues (Winter 1886). Species in this family are pathogens or endophytes in leaves of herbaceous or woody trees (Rossman et al. 2007). Betulaceae, Fagaceae, and Salicaceae are the most common host families for the gnomoniaceous taxa (Mejia et al. 2011). Gnomoniaceae comprises 34 genera (Senanayake et al. 2018, Minoshima et al. 2018).

Ecological and economic significance of Gnomoniaceae
Species in Gnomoniaceae mainly occur on living, fallen or attached, overwintered leaves and petioles, leaf blades or herbaceous stems and rarely on woody substrates (Sogonov et al. 2008). Members of this family are mostly reported from temperate regions. They occur as endophytes of woody plants or pathogens causing the disease to economically important hardwood trees (Danti et al. 2002, Green 2004, Moricca & Ragazzi 2008). Sycamore anthracnose by Apiognomonia veneta, strawberry stem rot by Gnomoniopsis fructicola, foliar disease of birch and dieback of young shoots by Discula betulae, and walnut anthracnose is caused and leaf blotch disease by Ophiognomonia leptostyla are common diseases caused by members of this family (Maas 1998, Green 2004, Green & Castlebury 2007, Pennycook 2007).