Nectriaceae Tul. & C. Tul., Select. fung. carpol. (Paris) 3: 3 (1865)
MycoBank number: MB 81059; Index Fungorum number: IF 81059; Facesoffungi number: FoF 01396; 2081 species.
Endophytic, foliicolous or saprobic on woody plant hosts, some are entomogenous, a few species are human pathogens, in terrestrial and aquatic habitats. Sexual morph: Ascomata stromatic or astromatic, white, red, dark red, reddish-brown, orange, orange-red, orange-brown, yellow, pale yellow, brown, greyish yellow-green, dark bluish, bluish purple, bluish black or black, solitary or aggregated in groups, perithecial, globose to subglobose, ovoid, elongate-ovoid, obpyriform, obovoid or pyriform, KOH +/-, surface smooth to papillate, striate, warted, verrucose or scaly, with or without setae, ostiolar region sometimes papillate, periphysate. Paraphyses present or absent. Asci 4–8-spored, unitunicate, clavate to narrowly clavate, cylindrical or ellipsoidal, with or without apical ring, with pointed or pedicellate base. Ascospores uniseriate to biseriate or overlapping, hyaline to yellow, yellow-brown, golden-brown, pale-brown or green, fusiform, long-fusiform, ellipsoidal, oblong, biconic, pyriform, reniform or allantoid, aseptate to multi-septate or muriform, constricted at the septum or not, smooth-walled, spinulose, verruculose or striate. Asexual morph: Mainly hyphomycetous, less commonly coelomycetous. Conidiomata synnematous, sporodochial or pycnidial. Conidiophores branched or unbranched, penicillate, verticillate. Conidiogenous cells monophialidic to polyphialidic, ampulliform to lageniform, cylindrical, elongate-ampulliform or subcylindrical, hyaline, smooth-walled. Conidia globose, ovate, ellipsoidal, cylindrical to subcylindrical, fusiform, long-fusiform, filiform, allantoid or falcate, straight to slightly or strongly curved, hyaline, aseptate to multi-septate, constricted at septum or not, with or without visible abscission scars, sometimes guttulate, smooth-walled. Chlamydospores present or absent (adapted from Maharachchikumbura et al. 2016b).
Type genus – Nectria (Fr.) Fr.
Notes – Nectriaceae species occur worldwide, have higher diversity in warm temperate and tropical regions (Rossman et al. 1999, Rossman 2000, Chaverri et al. 2011, Schroers et al. 2011, Hyde et al. 2014, Lombard et al. 2015). They are commonly found on bark of recently dead woody substrates, especially in tropical regions. Some are plant endophytes or pathogens, other fungi or insects (Rossman et al. 1999, Lombard et al. 2015).
Seaver (1909) divided Hypocreales into two families: Nectriaceae and Hypocreaceae, based on stromatic and perithecial characters. Petch (1938) also accepted Nectriaceae as a family in Hypocreales, while Munk (1957) and Dennis (1960) placed it in Sphaeriales. However, Kreisel (1969) and Rossman et al. (1999) accepted Nectriaceae and Hypocreaceae as two separate families in Hypocreales. Lumbsch & Huhndorf (2010) listed 26 genera in Nectriaceae. Maharachchikumbura et al. (2016b) and Lombard et al. (2015) accepted 47 genera in the family based on molecular data. The asexual morphs of Nectriaceae species are mainly hyphomycetous, except Thyronectria, which forms pycnidia (Wijayawardene et al. 2017b). Corinectria was introduced to the family by González & Chaverri (2017). Another genus Neothyronectria was added to Nectriaceae by Yang et al. (2019). Aiello et al. (2017) introduced the new genus Pleiocarpon, based on morphology and molecular data. Xenocalonectria was placed in synonymy with Xenocylindrocladium by Rossman et al. (2016). Rossman et al. (2016) synonymised Antipodium under Ophionectria. Pleonectria was considered as an synonym of Thyronectria by Wijayawardene et al. (2017b). Stachybotryna, previously listed in Nectriaceae by Maharachchikumbura et al. (2016b), was maintained in Ascomycota genera incertae sedis by Wijayawardene et al. (2018a). Wijayawardene et al. (2018a) accepted 63 genera in Nectriaceae including Baipadisphaeria, Varicosporella, Xenocylindrocladium and Xenoleptographium. A new name was proposed for the monotypic genus Curvicladium by Crous et al. (2016a), as the generic name “Curvicladium” was already occupied for a moss species.