Sirophoma Höhn., Hedwigia 59(5): 257 (1917)
Facesoffungi number: FoF 07590
Ascomycota, genera incertae sedis
Saprobic on the host plants in terrestrial habitat, such as Carpinus betulus (Betulaceae), Grewia villosa (Malvaceae), Nelumbo nucifera (Nelumbonaceae), Petroselinum sativum (Apiaceae), Sambucus racemose (Adoxaceae) and Viburnum opulus (Adoxaceae) (Sutton 1980, Index Fungorum 2019). Sexual morph: undetermined. Asexual morph: Conidiomata brown, pycnidial, solitary to gregarious, immersed, depressed globose, unilocular, glabrous. Ostiole single, circular, centrally located. Conidiomatal wall composed of thick-walled, dark brown cells of textura angularis in the exterior, becoming paler towards hymenium. Conidiophores formed from inner wall layer of conidiomata, hyaline, cylindrical, branched, septate, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic, cylindrical or doliiform, integrated or discrete, determinate, smooth-walled, with terminal or lateral apertures formed immediately below transverse septa, periclinal thickenings at the collarette zone. Conidia hyaline, globose to ellipsoid or pyriform, unicellular, smooth-walled, eguttulate (adapted from Sutton 1980).
Type species: Sirophoma singularis Höhn., Hedwigia 59(5): 257 (1917)
Notes: Sutton (1980) re-described and illustrated Sirophoma. An additional six species are listed in Index Fungorum (2019) but they have not been studied with molecular data. Sirophoma is similar to asexual morph of Tympanis (e.g. T. spermatiospora), Collophorina (≡ Collophora), Dendrodomus, Pyrenochaeta and Pleurophoma in having cylindrical, branched conidiophores with phialidic, acropleurogenous, branched conidiogenous cells. Collophorina (Tympanidaceae, Helotiales, Leotiomycetes) has pseudopycnidial conidiomata with textura epidermoidea wall, which differs from those in the other genera that are ostiolate pycnidia with textura angularis wall (Sutton 1980, Damm et al. 2010, Wijayawardene et al. 2017, Nasr et al. 2018). Pyrenochaeta is separated from other genera by its setose conidiomata. Sirophoma possesses hyaline, globose to ellipsoid or pyriform, aseptate conidia, whereas they are cylindrical in asexual morph of Tympanis, and ellipsoid to cylindrical in Dendrodomus and Pleurophoma. Dendrodomus differs from Pleurophoma by its paraphyses (Sutton 1980).
Distribution: Austria, Czech Republic, Finland, Pakistan, Romania (Sutton 1980, Index Fungorum 2019).
Sirophoma singularis (redrawn from Sutton 1980) a Vertical section of conidioma. b Conidia. c Conidiophores, conidiogenous cells and developing conidia.
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.