Sordariomycetes, Sordariomycetidae, Phyllachorales, Phaeochorellaceae
Saprobic on the host plant in terrestrial habitat. Sexual morph: undetermined. Asexual morph: Conidiomata dark brown to brownish black, stromatic, pycnidial, scattered to gregarious, immersed, globose, multilocular, glabrous. Ostiole absent, dehiscence by irregular splits of apical wall. Conidiomatal wall composed of thick-walled, brown, vertically arranged cells of textura angularis in the middle part, becoming darker, thick-walled cells of textura angularis to textura globosa at the base and lateral part. Conidiophores reduced to conidiogenous cells or when present, hyaline, cylindrical, unbranched, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic, cylindrical to ampuliform, integrated or discrete, determinate, smooth-walled. Conidia hyaline, subcylindrical, obtuse at the apex, narrowed and slightly truncate at the base, smooth-walled, guttulate (Nag Raj and DiCosmo 1978, Sutton 1980).
Type species: Cyclodomus umbellulariae Höhn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 118: 1528 (1909)
Notes: Sutton (1980) redescribed Cyclodomus and accepted the single species C. umbellulariae on dead leaves of Umbellularia californica (Lauraceae). Hyde et al. (1996) added second species C. aequatoriensis K.D. Hyde and linked it to the sexual morph Maculatifrondes aequatoriensis K.D. Hyde based on host association. Although C. aequatoriensis shares a similar structure of conidiomatal wall in the middle part with the type species, it also differs in many ways. Cyclodomus umbellulariae has multilocular conidiomata producing subcylindrical conidia (15–17 × 2–2.5 µm), whereas, C. aequatoriensis has unilocular conidiomata producing ellipsoidal to ovoid conidia (2–3 × 2–2.5 µm). Based on morphology, C. aequatoriensis is excluded from Cyclodomus. Cyclodomus is considered a member of Phyllachoraceae (Hyde et al. 2020). Fresh collections and DNA sequences of Cyclodomus are needed to confirm its placement.
Distribution: Pakistan, USA (https://www.gbif.org/).
Cyclodomus umbellulariae (redrawn from Nag Raj and DiCosmo 1978) a Vertical section of conidioma. b Conidiogenous cells and developing conidia. c Condia.
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.