Apiognomonia Höhn., Ber. dt. bot. Ges. 35(8): 635 (1917) = Discula Sacc., Syll. fung. (Abellini) 3: 674 (1884)
Facesoffungi number: FoF 07115
Sordariomycetes, Diaporthomycetidae, Diaporthales, Gnomoniaceae
Saprobic or parasitic on the host plant. Sexual morph: see Sogonov et al. (2007). Asexual morph: Conidiomata yellowish brown to black, acervular, solitary to gregarious, immersed to erumpent, irregularly round or oval in outline, subglobose in section view, unilocular, glabrous. Ostiole absent, dehiscence by irregular splits of the apical wall. Conidiomatal wall composed of thick-walled, yellowish brown cells at the base. Conidiophores restricted to the basal wall, hyaline, cylindrical, septate and branched, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic or annellidic, without or rarely with a few annellidic scars, lageniform to cylindrical, integrated, determinate, smooth-walled, tapered toward the apex. Conidia hyaline, broadly ellipsoid to oval, straight or slightly curved, aseptate, smooth-walled (Sogonov et al. 2007).
Type species: Apiognomonia veneta (Sacc. & Speg.) Höhn., Hedwigia 62: 47 (1920)
Notes: The asexual morph of Apiognomonia has been assigned to Discula on twigs, and Gloeosporum on leaves (Sogonov et al. 2007). Sogonov et al. (2007) revised Apiognomonia and confirmed its asexual morph in Discula. They resolved confusion concerning the correct name for the type species and related species of both Apiognomonia and Discula. Apiognomonia veneta and its asexual morph, D. nervisequa (Fuckel) M. Morelet (the earliest available epithet for D. platani), are the correct names for the type species of Apiognomonia and Discula, respectively (Sogonov et al. 2007). Discula umbrinella (Berk. & Broome) M. Morelet, was erroneously applied as the type species of Discula by Sutton (1980) and the erroneously applied asexual morph of A. errabunda (Sogonov et al. 2007). Because Apiognomonia is a well-defined genus (Sogonov et al. 2007, 2008), it was recommended to be used for the holomorph (Rossman et al. 2015). In this study, three fresh collections from Italy on dead branches of Fagus sp. are introduced as a new species A. pseudohystrix (strain MFLUCC 16–1311 and MFLUCC 16–1140) and an asexual morph of A. errabunda (strain MFLUCC 16–1318). Besides, A. lasiopetali described by Crous et al. (2016a) and A. rigniacensis (Monod 1983) clustered away from the epitype of A. veneta (CBS 119036) and are thus excluded from Apiognomonia. More collections are needed to evaluate the generic concept of Apiognomonia.
Distribution: Belgium, Canada, Czech Republic, France, Germany, Italy, New Zealand, Netherlands, Poland, Russia, Switzerland, UK, USA (Sogonov et al. 2007, this study).