Siroplacodium Petr., in Rechinger et al., Annln naturh. Mus. Wien 50: 509 (1940)
Facesoffunginumber: FoF 07592
Ascomycota, genera incertae sedis
Saprobic on the host plants in terrestrial habitat, e.g. Campanula (Campanulaceae), Solidago virgaurea (Asteraceae), Poaceae. Sexual morph: undetermined. Asexual morph: Conidiomata dark brown, stromatic, acervular, solitary to gregarious, immersed, applanate to lenticular, unilocular, glabrous. Ostiole absent, dehiscence by a longitudinal slit. Conidiomatal wall composed of thick-walled, dark brown to pale brown cells of textura angularis. Conidiophores arising from inner layers of basal stroma, hyaline, cylindrical, branched, septate, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic, cylindrical to subcylindrical, integrated or discrete, determinate, smooth-walled, with a long flared collarette and marked periclinal thickening around the apertures. Conidia hyaline, cylindrical with an obtuse apex and a slightly truncate base, unicellular, smooth-walled, eguttulate (adapted from Sutton 1980).
Type species: Siroplacodium atrum Petr., in Rechinger, Baumgartner, Petrak & Szatala, Annln naturh. Mus. Wien 50: 509 (1940)
Notes: Siroplacodium is similar to Cyclodomus and Blennoria in having cylindrical conidia. Cyclodomus is distinguished from Siroplacodium by its pycnidial conidiomata and cylindrical to ampulliform conidiogenous cells without a long flared collarette (Morgan-Jones et al. 1972, Sutton 1980). Blennoria was separated from Siroplacodium by its multilocular, pycnidial conidiomata. Six species are accepted in Siroplacodium, namely S. atrum, S. caulocarpum H. Ruppr., S. cudraniae G.C. Zhao & R.L. Zhao, S. longisporum Petr., S. shastense (R. Sprague & W.B. Cooke) Petr. and S. umbelliferarum Petr. (Sutton 1980, Zhao et al. 2012, Wijayawardene et al. 2017, Index Fungorum 2019). Except for the type species, the other taxa have not been re-studied. No molecular data is available for this genus. The taxonomy of this genus warrants further investigations based on fresh collections and phylogenetic inferences.
Distribution: China, Germany, Iran, Iraq (Zhao et al. 2012, Index Fungorum 2019).
Siroplacodium atrum (redrawn from Sutton 1980) a Conidia. b Conidiophores, conidiogenous cells and developing conidia. c Vertical section of conidioma.
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.