Fungalpedia – Note 1650, Sphaeriothyrium
Sphaeriothyrium Bubák
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig 1
Classification: Incertae sedis, Incertae sedis, Incertae sedis, Incertae sedis, Pezizomycotina, Ascomycota, Fungi
Habit on petiole of Struthiopteris germanica (Onocleaceae), Pteridium aquilinum (Dennstaedtiaceae). Sexual morph: undetermined. Asexual morph: Conidiomata dark brown, stromatic, pycnidial, solitary, immersed to semi-immersed, subglobose, unilocular, glabrous. Ostiole absent, dehiscence by breakdown of the upper wall. Conidiomatal wall composed of thick-walled, dark brown cells of textura angularis in the exterior, becoming paler towards hymenium. Conidiophores arising all around the cavity of conidioma, reduced to conidiogenous cells. Conidiogenous cells hyaline, enteroblastic, phialidic, ampuliform to doliiform, determinate, smooth-walled, with a minute apical channel and collarette, periclinal thickening at the collarette zone. Conidia hyaline, ellipsoid to cylindrical, unicellular, smooth-walled, eguttulate (adapted from Sutton 1980).
Notes: Sphaeriothyrium is similar to asexual morph of Plenodomus (e.g. P. lingam, syn. Phoma lingam) and Phoma in having pycnidial conidiomata producing ellipsoid to cylindrical or subcylindrical conidia (Verkley et al. 2014, Ariyawansa et al. 2015). However, no molecular data is available for this genus and it is, therefore, difficult to separate them by morphology. Fresh collections are needed to place it in a natural group and link it to its sexual morph.
Type species: Sphaeriothyrium filicinum Bubák, Ber. dt. bot. Ges. 34: 299 (1916)
Other accepted species: Species Fungorum – search Sphaeriothyrium.
Figure 1 – Sphaeriothyrium filicinum (redrawn from Sutton 1980) a Vertical section of conidioma. b Conidiogenous cells and developing conidium. c Conidia.
References
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.