Gyrostroma Naumov, Bull. Soc. mycol. Fr. 30(3): 386 (1914)
Facesoffungi number: FoF 07409
Sordariomycetes, Sordariomycetidae, Diaporthales, genera incertae sedis
Saprobic on bark of Abies sibirica (Pinaceae). Sexual morph: undetermined. Asexual morph: Conidiomata off white, extensive, stromatic, pycnidial, scattered to gregarious or confluent, initially immersed, ultimately become erumpent, pulvinate, globose to subglobose, unilocular or multilocular, glabrous. Ostiole absent, dehiscence by irregular breakdown of the locular walls. Conidiomatal wall composed of thick-walled, brown to hyaline cells of textura angularis. Conidiophores formed from the inner layer of locular wall, hyaline, cylindrical, branched, septate, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic, cylindrical to lageniform, integrated or discrete, determinate, smooth-walled. Conidia hyaline, oblong to ellipsoidal, unicellular, smooth-walled, eguttulate (adapted from Hirooka et al. 2012).
Type species: Gyrostroma sinuosum Naumov, Bull. Soc. mycol. Fr. 30(3): 386 (1914)
Notes: Seeler (1940b) revised Thyronectria and linked it to the asexual morph Gyrostroma, based on culture studies and both apothecia and conidiomata found compactly associated. Two new species, Gyrostroma austroamericanum Seeler and G. missouriense Seeler were introduced as asexual morph of T. austroamericana (Speg.) Seeler and T. missouriensis (Ellis & Everh.) Seaver, respectively (Seeler 1940b). Hirooka et al. (2012) re-examined the type specimen of G. sinuosum and suggested that it may be a member of Diaporthales rather than hypocrealean. Gyrostroma austroamericanum and G. missouriense were transferred to Pleonectria (synonym of Thyronectria) by Hirooka et al. (2012). Wijayawardene (2017) synonymized Kaskaskia (represented by K. gleditsiae Born & J.L. Crane) under Gyrostroma. However, Bedker (1983) synonymized Kaskaskia gleditsiae under Gyrostroma austroamericanum on the basis of morphology and culture study. Thus, Kaskaskia is a synonym of Thyronectria, rather than a synonym of Gyrostroma. It is necessary to obtain fresh collections and obtain DNA sequences to confirmed placement of Gyrostroma and allied genera.
Illustration of Gyrostroma sinuosum see Hirooka et al. (2012).
Distribution: Europe (Hirooka et al. 2012).
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.