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 Conidiophores, conidiogenous cells and developing conidia. b Conidia. c Vertical section of conidioma.