Phacidium Fr., Observ. mycol. (Havniae) 1: 167 (1815)
Facesoffungi number: FoF 07500
Leotiomycetes, Leotiomycetidae, Phacidiales, Phacidiaceae
Foliicolous or caulicolous. Sexual morph: Ascomata amphigenous, solitary to gregarious, rounded, initially immersed, later rupturing host tissues by irregular stellate splits. Peridium composed of dark brown pseudoparenchymatous cells of textura globosa in outer layers, and pale brown to hyaline cells in inner layers. Hymenium composed of asci and paraphyses. Paraphyses exceeding asci, hyaline, branched, septate, tubular, filiform, invested in mucilage, and frequently anastomosing. Asci clavate, 4–8-spored, with an amyloid (I+) dehiscence ring (in Melzer’s reagent). Ascospores hyaline, uni- to biseriate, ellipsoid to ellipsoid-fusoid, aseptate, smooth-walled, lacking mucoid appendages (adapted from DiCosmo et al. 1984). Asexual morph: Conidiomata pale brown, dark brown or black, variable, stromatic, pycnidial, solitary, gregarious or confluent, immersed to semi-immersed, or erumpent, multi-locular to unilocular, globose to subglobose, thick-walled, ostiolate. Ostiole circular or cylindrical to subcylindrical, uni-ostiolate or multi-ostiolate, with relatively long neck or short neck. Conidiomatal wall composed of thick-walled, dark brown cells of textura globulosa to textura angularis in outer layers, and inner layers of thick-walled, hyaline cells of textura angularis, textura epidermoidea, textura oblita or textura prismatica. Conidiophores arising from the inner cells of the locular walls, hyaline, branched or unbranched, septate. Conidiogenous cells hyaline, enteroblastic, phialidic, cylindrical, subcylindrical, lageniform, ampulliform or subclavate, discrete or integrated, indeterminate, smooth-walled. Conidia hyaline, fusiform to ellipsoid, or cylindrical, with broad and obtuse base, narrowed apex, aseptate, smooth-walled, bearing fan-shaped, funnel-shaped or irregular, mucoid appendage.
Type species: Phacidium lacerum Fr., Observ. mycol. (Havniae) 2: 312 (1818)
Notes: The genus Ceuthospora was published by Fries (1825) to accommodate Sclerotium inclusum J.C. Schmidt & Kunze ex Fr. and Sphaeria phaeocomes Rebent. Greville (1828) listed three species in Ceuthospora, C. phacidioides Grev., C. lauri Grev. and C. phaeocomes (Rebent.) Fr., of which C. phaeocomes was later selected as the lectotype for Ceuthospora by Fries (1832). Fries (1849) proposed the generic name Pyrenophora, and referred both Sclerotium inclusum and Sphaeria phaeocomes to the genus. The generic name Ceuthspora thus has not been correctly typified. Sutton (1972b) discussed the nomenclatural complexities of Ceuthospora and proposed the conservation of Ceuthospora Grev. 1827 with C. lauri as the lectotype species, over Ceuthospora Fr. 1825 with C. phaeocomes as the lectotype species. According to this concept, more than 100 taxa were included in Ceuthopsora, but no revision has yet been attempted (Sutton 1980). Nag Raj (1993) revised the genus based on some taxa and provided a key to 11 species.
Distribution: Argentina, Austria, Belgium, Canada, Chile, China, Czechoslovakia, Denmark, Finland, Germany, Italy, Portugal, Spain, Sweden, Switzerland, UK, USA, Tasmania, the Netherlands (Nag Raj 1993, Crous et al. 2014d, this study).
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.