Polycoccum
Polycoccum Saut. ex Körb., Parerga lichenol. (Breslau) 5: 470 (1865).
Index Fungorum number: IF 4309; Facesoffungi number: FoF 08782, 41 morphological species (Species Fungorum 2022), 4 species with molecular data.
Lichenicolous on various hosts. Sexual morph: Ascomata perithecioid, immersed to semi-immersed, visible as raised, black, shiny spot, enclosed in galls on host thallus, globose to subglobose, dark brown to black, scattered, gregarious in a gall. Ostiole apapillate. Peridium thin to thick-walled, composed of several layers of small to large polyhedral, dark brown to black, pseudoparenchymatous cells, arranged in textura angularis to textura epidermoidea. Hamathecium composed of dense, curly filamentous, richly branched, anastomosed, cellular pseudoparaphyses. Asci 8-spored, bitunicate, subcylindrical to cylindric-clavate, short-pedicellate, apically rounded, with ocular chamber. Ascospores 1–2-seriate, brown to dark brown, obovoid, uniseptate, constricted at septum, mostly upper cell larger than lower cell, smooth-walled. Asexual morph: Reported as coelomycete, forming pycnidia, with simple, oblong to elliptic, smooth-walled conidia (adapted from Zhurbenko 2010, Ertz et al. 2015).
Type species: Polycoccum sauteri Körb.
Notes: Polycoccum is characterised by perithecioid, immersed to semi-immersed ascomata, subcylindrical to cylindric-clavate asci and brown to dark brown, obovoid, uniseptate ascospores. The taxonomy of Polycoccum has undergone various changes in recent years. Saccardo (1882) regarded Polycoccum as a synonym of Didymosphaeria. Polycoccum differs from Didymosphaeria in ascomatal feature (Hawksworth & Diederich 1988). Santesson (1960) re-instated Polycoccum. Vězda (1969) provided a key to ten Polycoccum species. Hawksworth and Diederich (1988) accepted 23 species, excluded 29 epithets and provided a key to accepted Polycoccum species. Atienza et al. (2003) and Gardiennet (2012) provided additional keys to species. Lawreya and Diederich (2015) accepted 57 species in Polycoccum. Several authors added new species (Brackel & Berger 2010, Zhurbenko & Dillman 2010, Halici et al. 2013, Hafellner 2015). Eriksson and Hawksworth (1986) treated Polycoccum in Pleosporaceae. Hawksworth and Diederich (1988) referred Polycoccum to Dacampiaceae based on morphology. Ertz et al. (2015) introduced Polycoccaceae to accommodate Polycoccum based on morphology and phylogenetic analyses of LSU sequence data. Ertz et al. (2015) reported that species of Polycoccum sensu lato are closely related to lichenicolous Phoma-like taxa in Phaeosphaeriaceae and five isolates of Polycoccum sensu stricto clustered close to Clypeococcum in Polycoccaceae. The main group of Polycoccum is characterised by thick-walled, distinctly ornamented ascospores. On top of that, Polycoccum sensu stricto is characterised by formation of ascomata on the host thallus, an affinity to produce galls, and some structures of the ascomatal wall such as cells ± isodiametric in vertical section, the hamathecium comprising thick paraphysoids, the ascus largely cylindrical to subclavate, usually with irregularly distichously arranged ascospores (Ertz et al. 2015). Doilom et al. (2018) re-examined the holotype of Polycoccum sauteri (S-F45264) and provided an updated description of the genus. Polycoccum is morphologically and phylogenetically a distinct genus in Polycoccaceae. Only LSU sequence data is available for Polycoccum clauzadei, P. pulvinatum, P. trypethelioides and P. vermicularium.
Recent News
Recent paper to be publishedRecent Genus
NothocladosporiumPhillipsiella
Ampelomyces
Recent Species
Nothocladosporium syzygiiPhillipsiella atra
Curreya conorum
