Parasitic or saprobic on woody branches and rarely on leaves in terrestrial habitats. Sexual morph: Ascomata black, immersed to erumpent, solitary or gregarious, globose to subglobose, usually uniloculate, thick-walled, sometimes ostiolate. Peridium composed of several layers of brown to dark brown pseudoparenchymatous cells of textura angularis. Hamathecium lacking pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, saccate to broad-clavate, becoming cylindric-clavate just before rupture, with a short bifurcate pedicel or apedicellate, apex broadly rounded with a distinct ocular chamber. Ascospores 2-seriateto triseriate, partially overlapping, hyaline, 3 to many septate, muriform to phragmosporous, obovoid or elliptic with broadly to narrowly rounded ends. Asexual morph: aureobasidium-like; conidia hyaline or brownish, ovate, aseptate (adapted from Barr 1972; Thambugala et al. 2014).
Type species: Saccothecium sepincola (Fr.) Fr.
Notes: Saccothecium is characterised by globose to subglobose ascomata, saccate to broad-clavate asci, 2-seriate to triseriate muriform to phragmosporous ascospores. Kirschstein (1939) added two new species to Saccothecium, and Vasilyeva and Mel’nik (2006) introduced S. cornicola. Pande (2008) transferred several species from Pringsheimia or Metasphaeria to Saccothecium but most of them were invalid (Index Fungorum 2022). Wehmeyer (1957) and Holm (1957) suggested S. sepincola as the lectotype of Saccothecium. Froidevaux (1972) and Sivanesan (1984) synonymized Saccothecium sepincola under Pringsheimia sepincola and designated P. sepincola as the type species of Pringsheimia. Barr (1972) assigned Saccothecium to Dothioraceae based on characters of the peridium, asci and ascospores characters and this was followed by subsequent authors (Barr 1987; 2001; Kirk et al. 2008; Lumbsch and Huhndorf 2010). Barr (2001) considered Pringsheimia as a distinct genus from Saccothecium. In the phylogenetic analysis of Schoch et al. (2009) and Zhang et al. (2012), Saccothecium sepincola (CBS 278.32) formed a lineage in Didymellaceae. Zhang et al. (2012) transferred Saccothecium in Pleosporales genera incertae sedis. Thambugala et al. (2014) collected S. sepincola from Italy and their strain clustered in Aureobasidiaceae (= Saccotheciaceae). Thambugala et al. (2014) placed Saccothecium in Saccotheciaceae based on phylogenetic analysis. The original specimen of S. sepincola by Fries (1836) is lost. There is no information regarding the host, location, and collection details of this original specimen. We re-examined the Saccothecium sepincola (MFLU 14−0276) and designate it below as an epitype. The basionym of Saccothecium sepincola, Sphaeria sepincola was found on dead stems of Rosa (Rosaceae) in Sweden. This specimen (MFLU 14–0276) was collected on twigs of Cornus sanguinea (Cornaceae) in Italy and has sequence data in GenBank. Molecular data available for Saccothecium are ITS, LSU, SSU, TEF-1 and RPB2.