Clypeosphaeriaceae G. Winter, Rabenh. Krypt.-Fl., Edn 2 (Leipzig) 1.2: 554 (1886)
MycoBank number: MB 80613; Index Fungorum number: IF 80613; Facesoffungi number: FoF 01776; 53 species.
Hemibiotrophic or saprobic on woody or herbaceous plants. Sexual morph: Pseudoclypeus comprising both host and fungal tissues, black. Ascomata immersed to erumpent, rarely superficial, solitary or aggregated, globose to subglobose, coriaceous, brown to black, ostiolate, papillate. Papilla short, narrow, internally lined with hyaline, filamentous periphyses. Peridium comprising dark brown to light brown, thick-walled cells of textura angularis, inwardly hyaline. Paraphyses numerous, hypha-like, septate, flexuose, embedded in a gelatinous matrix. Asci 8-spored, unitunicate, cylindrical to broadly cylindrical, pedicellate, with a wedge-shaped, J-, or J+, apical ring. Ascospores uniseriate to biseriate, hyaline to brown, ellipsoidal to fusiform, sometimes oval, straight or curved, unicellular or septate, wall smooth or ornamented or striate, sometimes with sheaths, appendages, rarely with germ slits or germ pores. Asexual morph: Undetermined.
Type genus – Clypeosphaeria Fuckel
Notes – Lindau (1897) resurrected Sphaeriales to accommodate Clypeosphaeriaceae which has been accommodated in Xylariales (Krug 1978, Barr 1990b, 1994, Eriksson & Hawksworth 1993, Eriksson & Winka 1997, Hawksworth et al. 1995, Smith et al. 2003, Douanla-Meli & Langer 2012, Hernandez-Restrepo et al. 2015, Maharachchikumbura et al. 2015, 2016b). Senanayake et al. (2015) excluded Clypeosphaeriaceae from Xylariales and transferred it to Amphisphaeriales. Jaklitsch et al. (2016b) did not accept Amphisphaeriales because it lacked phylogenetic support in their analysis. Furthermore, in their analysis, the generic type of Clypeosphaeria; C. mamillana clusters as a basal clade within Xylariaceae. Therefore, they discontinued Clypeosphaeriaceae and synonymised under Xylariaceae. However, in present study (Fig. 4 ) the family type; C. mamillana form a distinct clade apart from Xylariaceae as a sister taxon to the Induratiaceae. Therefore, here we maintain Clypeosphaeriaceae as a distinct family in Xylariales. However, most genera placed in this family lack molecular data and the arrangement is reliant on ascospores being apiosporous, asci having a J-, or J+, aprical ring and immersed ascomata.
Figure 4 – Phylogram generated from maximum likelihood analysis based on combined ITS, LSU, rpb2 and tub2 sequence data for Xylariomycetidae. Two hundred and seventy-two strains are included in the combined analyses which comprised 4211 characters (1168 characters for ITS, 937 characters for LSU, 1128 characters for rpb2, 978 characters for tub2) after alignment. Achaetomium macrosporum (CBS 532.94), Chaetomium elatum (CBS 374.66) and Sordaria fimicola (CBS 723.96) are outgroup taxa. Single gene analyses were carried out and the topology of each tree had clade stability. The best RaxML tree with a final likelihood value of – 132297.706952 is presented. Estimated base frequencies were as follows: A = 0.241914, C = 0.251908, G = 0.265558, T = 0.240620; substitution rates AC = 1.281946, AG = 3.512297, AT = 1.499895, CG = 1.121065, CT = 6.472834, GT = 1.000000; gamma distribution shape parameter a = 0.678614. Bootstrap support values for ML greater than 75% are given near the nodes. Ex-type strains are in bold. The newly generated sequences are indicated in blue.