Idiocercus B. Sutton, Can. J. Bot. 45(8): 1255 (1967)
Ascomycota, genera incertae sedis
Saprobic or parasitic on leaves of Harungana madagascariensis (Hypericaceae) and Eucalyptus gracilis (Myrtaceae) (Sutton 1967, Swart 1988, Crous et al. 1990). Sexual morph: undetermined. Asexual morph: Conidiomata brown to dark brown, pycnidial, solitary, immersed, globose to subglobose, unilocular, glabrous, ostiolate. Ostiole single, circular, papillate. Conidiomatal wall composed of thin-walled, brown cells of textura prismatica in the basal and lateral part, becoming thick-walled, dark brown cells of textura globulosa at ostiolar region. Conidiophores often reduced to conidiogenous cells. Conidiogenous cells arising from inner wall layer of conidiomata, hyaline, enteroblastic, annellidic, indeterminate, smooth-walled, and of two kinds: a) those producing macroconidia lining the base and up the side walls of the conidioma, subcylindrical to irregular; b) those producing microconidia restricted to the inner layer of the conidiomatal wall close to the ostiolar region, subcylindrical to broadly ampulliform. Macroconidia hyaline, clavate to ellipsoid, unicellular, smooth-walled, with or without a tubular, conical, short apical appendage. Microconidia hyaline, unicellular, smooth-walled.
Type species: Idiocercus pirozynskii B. Sutton, Can. J. Bot. 45(8): 1256 (1967)
Notes: Sutton (1967) introduced Idiocercus to accommodate I. pirozynskii (generic type) and I. macarangae (T.S. Ramakr.) B. The third species I. australis (Cooke) H.J. Swart was described from Eucalyptus gracilis (Myrtaceae) by Swart (1988). Nag Raj (1993) re-examined the type specimen and emended the description and illustration of Idiocercus. Idiocercus australis was excluded from the genus because of its conidial morphology. Idiocercus macarangae was designated as the type for the new genus Xenidiocercus Nag Raj. Wu and Sutton (1995) and Wijayawardene et al. (2017b) accepted I. australis as a separate species in Idiocercus. We check the description and illustration of I. australis and then excluded this species from Idiocercus as Nag Raj (1993). Idiocercus pirozynskii has annellidic conidiogenous cells with widely-spaced, flared annellations, which differs those conidiogenous cells in I. australis no flared annellations. In addition. Idiocercus pirozynskii has hyaline, clavate to ellipsoid, unicellular conidia with or without tubular, conical apical appendage. However Idiocercus australis has cylindrical to long clavate or slightly elliptical conidia lacking an apical appendage (Crous et al. 1990). There is no sexual morph linked to Idiocercus, and no molecular data is available.
Distribution: Sierra Leone, Tanzania (Nag Raj 1993).
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.