Chaetomiaceae G. Winter, Rabenh. Krypt.-Fl., Edn 2 (Leipzig) 1.2: 153 (1885)

Index Fungorum number: IF 80582; MycoBank number: MB 80582Facesoffungi number: FoF 01842; 506 species.

Saprobic or parasitic on plant debris, straw, seeds,  dung, feathers of birds, soil, paper, textiles, air, mushrooms, rabbits, and humans. Sexual morph: Ascomata perithecial or cleistothecial, colourless to light brown or carbonaceous, egg-yellow, grey olivaceous to (greenish) grey, golden brown, or brown to black, solitary to scattered to gregarious, superficial or immersed to semi-immersed, subglobose to obpyriform, globose, ellipsoidal, ovoid to pyriform, cylindrical, covered with hairs, setae or glabrous, hairs may be simple or branched and of one or two types, ostiolate or lacking ostioles. Peridium with thick walls, comprising several layers of hyaline or brown cells of textura epidermoidea to textura intricata. Paraphyses absent or greatly reduced if present septate, hyaline. Asci 4- or 8-spored, unitunicate, clavate, cylindrical, obovate or ellipsoidal, pedicellate, without apical structures or with an indistinct thickened ring, evanescent, with wall dissolving at maturity. Ascospores irregularly arranged, at first colourless and dextrinoid (translucent, greenish, dark), brown to black, opaque when mature, ellipsoidal, globose, subglobose, oval, fusiform or triangular, with single or sometimes two germ pores, aseptate, with thick, smooth walls. Asexual morph: Hyphomycetous. Conidiophores absent or when present simple, hyaline, branched, septate, smooth-walled or slightly rough. Conidiogenous cells phialidic or blastic, verticillate or solitary, hyaline, consisting of a lageniform or ellipsoid swollen basal portion, cylindrical. Conidia dimorphic, first type holoblastic, hyaline to brown, smooth, globose-to obclavate, 1-celled, formed on hyphae or cylindrical conidiogenous cells, single or racemose, clusters; second type produced from phialides, hyaline to brown, lutescent, or dark brown, subglobose to globose or ellipsoidal, occasionally cylindrical, pyriform or fusiform, formed singly or in chains, 1-celled, with thick, smooth wall (adapted from Maharachchimbura et al. 2016b).

Type genusChaetomium Kunze

Notes – Chaetomiaceae was introduced by Winter (1885a) as “Chaetomieae”. It belongs to Sordariales (Hawksworth & Wells 1973, Mehrotra & Aneja 1990, Huhndorf et al. 2004b, Kirk et al. 2008, Lumbsch & Huhndorf 2010, Maharachchikumbura et al. 2015, 2016b, Hongsanan et al. 2017). A key for 20 genera of Chaetomiaceae was provided by Maharachchikumbura et al. (2016b). Based on the phylogenetic analyses of rpb2, tub2, ITS and LSU gene regions, Wang et al. (2016a) introduced five new genera: Amesia, Arcopilus, Collariella, Dichotomopilus and Ovatospora in Chaetomiaceae. In a recent paper, Wijayawardene et al. (2018a) listed 26 genera as belonging to this family. A new genus, Arxotrichum, was introduced by Crous et al. (2018d) for a strain of Chaetomium succineum and a new isolate of Arxotrichum yomingense. Based on the results of rpb2 and a combined rpb2, tub2, ITS and LSU dataset, Mycothermus was validated as a new genus, and the taxonomic status of Remersonia was determined in Chaetomiaceae by Wang et al. (2019b).