Preussia Fuckel, Hedwigia 6: 175 (1867).
Habitat terrestrial, saprobic (on decaying fibers or coprophilous). Sexual morph: Ascomata small- to medium-sized, cleistothecial or perithecial, solitary or scattered on substrate surface, globose, membraneous, black. Peridium thin, composed of thick-walled, poly-angular cells from the surface view. Pseudoparaphyses not observed. Asci (4-) 8-spored, bitunicate, clavate to broadly clavate, with a long and thin and furcate pedicel. Ascospores 3–6 seriate to uniseriate near the base, cylindrical with rounded ends, brown, septate, easily breaking into partspores, with germ slits in each cell. Asexual morph: Phoma (von Arx, 1973; Cain, 1961; Malloch & Cain, 1972).
Type species: Preussia funiculata (Preuss) Fuckel
Notes: Preussia was introduced by Fuckel (1866) with P. funiculata as type species. Preussia is characterized by small- to medium-sized, cleistothecial or perithecial ascomata, clavate to broadly clavate asci and cylindrical with rounded ends, brown, septate ascospores with presence of germ slits in each cell. Preussia morphologically resembles Sporormia and Sporormiella in having ascospores with conspicuous germ slits, surrounded by a hyaline gelatinous sheath. Preussia differs from Sporormia in that the latter has perithecioid ascomata and cylindrical asci while Preussia has cleistothecial ascomata. Preussia differs from Sporormiella in that the former has cleistothecioid ascomata while Sporormiella has dark brown, glabrous or hairy uniloculate pseudothecia. These differences in morphological characters have been reported to have very little phylogenetic significance (von Arx, 1973; Zhang et al., 2009a). Members of Sporormiella and Preussia have been differentiated based on ecological concept, and host preference with Sporormiella having a coprophilous habitat while Preussia has a saprobic lifestyle occurring in plant debris, wood or soil (von Arx & van der Aa, 1987). Cain (1961) accepted 12 species of Preussia with some of them having a coprophilous lifestyle. Guarro et al. (1997b) rejected this concept as P. intermedia (Clum) was found from soil and dung. Since then, several authors added new species to Preussia (Rai & Tewari, 1963; Soláns, 1985; Guarro et al., 1997; Abdullah et al., 1999; Arenal et al., 2005; Chang & Wang, 2009; Kruys & Wedin, 2009; Kruys et al., 2015; Crous et al., 2018; Diederich et al., 2018). In the phylogenetic analysis of Kruys and Wedin (2009) based on ITS, LSU, mtSSU and β-tubulin sequence data, Preussia clustered together with Sporormiella and Spororminula. Kruys and Wedin (2009) treated Sporormiella and Spororminula as synonyms of Preussia. Preussia sensu lato is morphologically and phylogenetically a distinct genus in Sporormiaceae.