Amphisphaeriaceae G. Winter, Rabenh. Krypt.-Fl., Edn 2 (Leipzig) 1.2: 259 (1885)

MycoBank number: MB 80452; Index Fungorum number: IF 80452; Facesoffungi number: FoF 00673; 105 species.

Saprobic on leaves, twigs, and branches of deciduous shrubs and trees, conifers or monocotyledons and occasionally hemibiotrophic or necrotrophic, appearing as slightly raised, black dots on host surface, often surrounded by a darkened area. Sexual morph: Pseudostromata when present made up of host cells and brown to black fungal hyphae, solitary, uni- to bi-loculate, hemisphaerical, initially appearing as raised, pale brown areas, with small, black dots at the center, becoming dark at maturity, glabrous. Ascomata perithecial, scattered to clustered, immersed in host cortex, becoming raised, subglobose to lenticular, glabrous, dark brown to black, vegetative hyphae surrounding the locules, ostioles individual, central. Papilla erumpent through host surface, internally lined by hyaline, filamentous periphyses. Peridium of unequal thickness, thinner at the base, thicker towards the mid-upper section of the ascomata, comprising several layers of dark brown pseudoparenchymatous cells, the outer layer of thick-walled, brown cells of textura prismatica, the inner layer of flattened, hyaline cells of textura prismatica. Paraphyses numerous, septate, filamentous. Asci 8-spored, unitunicate, cylindrical, short pedicellate, apex rounded, with J+ or J-, apical ring. Ascospores overlapping uniseriate, light to dark brown, ellipsoidal to fusiform, 1-septate. Asexual morph: Coelomycetous. Conidiomata solitary or aggregated, globose, dark brown. Peridium comprising thick-walled, septate, brown mycelium. Conidiophores dichotomously branched, septate, thick-walled, smooth, hyaline. Conidiogenous cells elongated, wide at the base and narrow at the tip, thin-walled, hyaline. Conidia hyaline, 1-celled, smooth-walled, elongate to fusiform, narrow at both ends (adapted from Maharachchimbura et al. 2016).

Type genusAmphisphaeria Ces. & De Not.

Notes – Amphisphaeriaceae was introduced by Winter (1885a) as ‘Amphisphaerieae’ and later established as Amphisphaeriaceae to accommodate the type genus Amphisphaeria and similar genera, viz. Caryospora, Ohleria, Strickeria, Trematosphaeria and Winteria (Winter 1887). Kirk et al. (2008) confirmed the family within the Xylariales comprising 32 genera with 499 species. Senanayake et al. (2015) accepted only the type genus Amphisphaeria while excluding all other genera based on their morphology and phylogeny. Some were transferred to Bartaliniaceae, Discosiaceae, Iodosphaeriaceae, Sporocadaceae, and Phlogicylindriaceae. Jaklitsch et al. (2016b) and Maharachchikumbura et al. (2016b) accepted only Amphisphaeria and Lepteutypa as belonging to the family based on molecular phylogenetic studies.

Earlier, Amphisphaeriaceae was classified in Xylariales and thought to share a close relationship with Cainiaceae, Clypeosphaeriaceae, and Hyponectriaceae (Jeewon 2002). However, Senanayake et al. (2015) resurrected Amphisphaeriales, which was introduced by Eriksson & Hawksworth (1986a) based on combined gene analyses. Amphisphaeriales was not followed in Maharachchikumbura et al. (2016b) and Jaklitsch et al. (2016b). Samarakoon et al. (2016) and Hongsanan et al. (2017) provided divergence estimates as additional information for Amphisphaeriales. Wijayawardene et al. (2018a) accepted three genera Amphisphaeria, Griphosphaerioma, and Lepteutypa in Amphisphaeriaceae (Amphisphaeriales).