Pyrenochaetopsis Gruyter, Aveskamp & Verkley

Pyrenochaetopsis Gruyter, Aveskamp & Verkley Notes. The genus Pyrenochaetopsis was introduced by de Gruyter et al. (2010), as a saprobe on Poaceae and typified with Py. leptospora. Currently, 27 species are recognized in MycoBank (Accession date: March 10, 2025) for Pyrenochaetopsis. Pyrenochaetopsis species have been described based on either their sexual or asexual stages or both. The asexual stage is characterized by olivaceous to olivaceous-black or pale brown to brown, solitary to confluent, superficial or submerged, globose to subglobose pycnidial conidiomata that may have a non-papillate or papillate ostiolar neck. The pycnidial wall, composed of textura angularis or textura globulosa, is pseudoparenchymatous and often bears setae. Conidiogenous cells are phialidic, hyaline, and born on acropleurogenous conidiophores. The conidia are aseptate, hyaline, ovoid to cylindrical or oblong, smooth-walled and guttulate (de Gruyter et al. 2010; Valenzuela-Lopez et al. 2018; Samarakoon et al. 2024). The sexual stage is represented by brown to dark brown or dark grey to black, globose to subglobose, solitary or scattered, superficial or immersed to semi-immersed ascomata with short papillate ostiole covered with reddish-brown setae, and a pseudoparenchymatous peridium composed of dark brown, textura angularis to textura prismatica. Asci are cylindric-clavate, fissitunicate, bitunicate and eight-spored. Ascospores are hyaline to pale brown, yellowish-brown, or yellowish-gray, fusiform to oblong in shape, smooth-walled, and three- to four-septate (Mapook et al. 2020; Phookamsak et al. 2022; Absalan et al. 2024). These species are widely distributed around the world and can be found in diverse ecological niches, functioning as saprobes, endophytes, or pathogens (de Gruyter et al. 2010; Surono et al. 2023). However, most of the species are associated with plant debris, soil, or dung while some have also been discovered on opportunistic infections in nematode cysts or human tissues (Valenzuela-Lopez et al. 2018).