Sphaerographium Sacc., Syll. fung. 3: 596 (1884)
Facesoffungi number: FoF 07595
Leotiomycetes, Leotiomycetidae, Chaetomellales, Chaetomellaceae
Saprobic on the host plants, such as Camellia sasanqua (Theaceae), Lonicera sp. (Caprifoliaceae) and Sorbus sp. (Rosaceae). Sexual morph: undetermined. Asexual morph: Conidiomata dark brown to black, pycnidial, solitary or gregarious, superficial or erumpent, cylindrical to conical, unilocular, glabrous or sometimes rostrate. Ostiole single, circular. Conidiomatal wall composed of relatively thick-walled, dark brown, gelatinized cells of textura angularis in the exterior, gradually merging with pale brown cells of textura oblita, becoming thick-walled cells of textura porrecta towards the apex. Conidiophores arising from inner layers of the basal and lateral wall of conidiomata, hyaline, cylindrical, branched, septate, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic, cylindrical to lageniform, integrated or discrete, determinate, smooth-walled, with terminal or lateral apertures formed immediately below transverse septa. Conidia hyaline, fusiform, falcate, 1–3-septate, smooth-walled, eguttulate (adapted from Sutton 1980, Verkley 2002).
Type species: Sphaerographium squarrosum (Riess) Sacc., Syll. fung. 3: 597 (1884)
Notes: Sphaerographium closely resembles Corniculariella (Dermateaceae, Helotiales) in having cylindrical to conical, rostrate conidiomata. However, Corniculariella has falcate or fusiform to clavate, 1–10-septate conidia, whereas Sphaerographium has fusiform, falcate, 1–3-septate conidia.
Sphaerographium was originally proposed by Saccardo (1884b) to accommodate nine species. von Höhnel (1915) lectotypified Sphaerographium with S. lonicerae (Fuckel) Sacc. as type species. Sutton (1980) gave a detailed generic description of the type species. A comprehensive revision of Sphaerographium was made by Verkley (2002), who neotypified Sphaerographium with S. squarrosum as the type species, which was listed as synonym of S. lonicerae by Sutton (1980). Verkley (2001, 2 Höhnel (1924) re-examined both type materials 002) accepted three species, S. petiolicola P. Karst., S. squarrosum and S. tenuirostrum Verkley, while 30 taxa were excluded or some insufficiently known taxa were discussed. Sphaerographium is placed in Chaetomellaceae (Helotiales, Leotiomycetes) based on molecular data (Decock et al. 2005, Minnis et al. 2010), but molecular data for the type species is unavailable. It is necessary to obtain fresh material and obtain DNA sequence data to confirm its placement. The sexual morph of this genus is undetermined.
Distribution: Austria, Finland, Germany, New Zealand, USA, Sweden, Switzerland (Sutton 1980, Verkley 2002).
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.