Amphisphaeriales D. Hawksw. & O.E. Erikss., Syst. Ascom. 5 (1): 177 (1986)

Index fungorum number: IF90458

Saprobic, pathogenic or endophytic on plants, appearing as black spots on the host substrate, made up of fungal hyphae and host cells. Sexual morph: Pseudostromata or stromata if present, with immersed to erumpent, solitary, rarely aggregated, scattered, globose to subglobose, coriaceous, brown to black, ostiolate, ascomata with periphyses. Peridium with one or few layers, mostly comprising an outer layer of thickwalled, brown cells and inner layer of thick or thin-walled, hyaline cells. Hamathecium comprising septate, hyaline, paraphyses. Asci 8-spored, unitunicate, cylindrical, clavate or narrowly globose, short pedicellate, with J+ or J- apical ring. Ascospores uniseriate or multi-seriate, hyaline, light brown to dark brown, ellipsoid, apiosporous, fusiform or oval, unicellular to 4-septate smooth or ornamented, sometimes bearing hyaline, slender, unbranched appendages, sometimes with a gelatinous sheath. Asexual morph: Coelomycetous. Conidiomata stromatic, solitary to gregarious, immersed to erumpent, acervular, pycnidial to irregular, unilocular or irregularly plurilocular, dark brown to black. Peridium comprising brown cells of textura angularis. Conidiophores indistinct or if distinct, arising from the inner layer cells of basal stroma, sometimes reduced to conidiogenous cells, long, cylindrical, hyaline, septate and sometimes branched. Conidiogenous cells discrete, holoblastic, annelledic, indeterminate, integrated, cylindrical, ampulliform, or lageniform, smooth, hyaline, becoming pale brown with age. Conidia cylindrical, clavate, ellipsoid or fusiform, aseptate to 4-euseptate, hyaline, subhyaline, pale olivaceous or brown, bearing cellular, filiform or attenuated, sometimes only apical or having both apical and basal appendages.

Notes: Amphisphaeriales has been accepted in consecutive studies using multigene phylogenies in the subclass Xylariomycetidae (Senanayake et al. 2015, Samarakoon et al. 2016b, Hongsanan et al. 2017, Crous et al. 2018b). However, based on previous studies, Wijayawardene et al. (2018a) accepted 11 families in Amphisphaeriales, i.e. Amphisphaeriaceae, Apiosporaceae, Beltraniaceae, Clypeophysalosporaceae, Hyponectriaceae, Melogrammataceae, Oxydothidaceae, Phlogicylindriaceae, Pseudomassariaceae, Sporocadaceae and Vialaeaceae, while Cainiaceae, Coniocessiaceae, and Iodosphaeriaceae were accepted in Xylariomycetidae families incertae sedis. In this study, Amphisphaeriales is a moderately supported clade sister to Xylariales and comprises 17 families viz. Amphisphaeriaceae, Apiosporaceae, Beltraniaceae, Castanediellaceae, Clypeophysalosporaceae, Cylindriaceae, Hyponectriaceae, Iodosphaeriaceae, Melogrammataceae, Oxydothidaceae, Phlogicylindriaceae, Pseudomassariaceae, Pseudosporidesmiaceae, Pseudotruncatellaceae, Sporocadaceae, Vialaeaceae, and Xyladictyochaetaceae. The divergence time for Amphisphaeriales has been estimated as 133 MYA. This number did not include Vialaeaceae because this family goes to Xylariales in MCC tree. Currently, there are 17 families and 88 genera in this order

Fig. 1 Consensus tree resulting from a Maximum Likelihood analysis of„ the combined LSU and ITS sequence alignment of Xylariomycetidae and other isolates in Sordariomycetes. Families are indicated in coloured blocks. RAxML bootstrap support values (MLB above 50 %), Bayesian posterior probabilities (PP above 90 %) and maximum parsimony bootstrap support values (MPB above 50 %) are given at the nodes (MLB/PP /MPB). The scale bar represents the expected number of changes per site. The tree was rooted to Dothidea sambuci and Botrytis fuckeliana.