Chaetomastia (Sacc.) Berl., Icon. fung. (Abellini) 1(1): 38 (1890).
Saprobic on host. Sexual morph: Ascomata relatively small, scattered, or in small groups, superficial, globose or subglobose, black, papillate, ostiolate, coriaceous. Peridium relatively thin, 1-layered, composed of heavily pigmented cells of textura angularis. Hamathecium of dense, long cellular pseudoparaphyses, embedded in mucilage. Asci mostly 4-spored, bitunicate, fissitunicate, broadly cylindrical with a furcate pedicel, with a large ocular chamber, especially apparent in immature asci. Ascospores ellipsoid to broadly fusoid with broadly to narrowly rounded ends, brown, 3-septate, constricted at all septa. Asexual morph: coelomycetous where known. Conidia hyaline or brown, aseptate or 1-septate (Aposphaeria- or Coniothyrium-like) (adapted from Zhang et al. 2012).
Type species: Chaetomastia hirtula (P. Karst.) Berl.
Notes: Chaetomastia was introduced by Saccardo (1883) as a subgenus of Melanomma to accommodate five species namely M. canescens, M. cucurbitarioides, M. hirtulum, M. hispidulum and M. pilosellum. Berlese (1890) raised Chaetomastia to genus rank. Clements and Shear (1931) selected Chaetomastia hirtula as the lectotype. Several authors reported that Chaetomastia has unitunicate asci (Eriksson & Hawksworth, 1986, 1998; Eriksson, 1999). Holm (1957) did not agree and confirmed that the asci are bitunicate. Holm (1957) treated C. hirtula as Melanomma hirtulum. Leuchtmann (1985) transferred this taxon to Montagnula sensu lato based on morphology namely the ellipsoid to broadly fusoid, brown, 3-septate, ascospores and the hyphae surrounding the ascomata. Barr (1987b) mentioned that Montagnula sensu stricto must be placed in Phaeosphaeriaceae based on the ascoma, peridium and ascospore characters while the ascomata and peridium structure of Chaetomastia fits the concept of Dacampiaceae (Barr, 1987b). Chaetomastia hirtula also resembles the type species of Massariosphaeria, M. phaeospora in peridium and ascospore characters. Barr (1989c) transferred several phragmosporous species of Massariosphaeria sensu lato to Chaetomastia based on morphology. Later, Barr (2002) reassigned Chaetomastia to Teichosporaceae based on its saprobic lifestyle and peridium structure. This treatment has been followed by several authors (Eriksson, 2006; Lumbsch & Huhndorf, 2007; Zhang et al., 2012). Chaetomastia is currently a distinct genus in Teichosporaceae but molecular data is not available. Fresh collections with DNA sequence data are needed to confirm the taxonomic placement of the genus. Chaetomastia needs epitypification.