Phloeosporella Höhn., Öst. bot. Z. 66: 106 (1916)
Faceoffungi number: FoF 07491
Ascomycota, genera incertae sedis
Parasitic on the host plant in terrestrial habitat. Sexual morph: undetermined. Asexual morph: Conidiomata dark brown to black, acervular, solitary to gregarious, unilocular, glabrous. Ostiole absent. Conidiomatal wall composed of thick-walled, pale brown to hyaline cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells hyaline, holoblastic, sympodial, lageniform to cylindrical, indeterminate, smooth-walled. Conidia hyaline, cylindrical to subcylindrical, tapered gradually towards obtuse apex, truncated at the base, 1–5-septate, straight or slightly curved, smooth-walled, guttulate (adapted from Sutton 1980).
Type species: Phloeosporella ceanothi Höhn., Öst. bot. Z. 66: 106 (1916)
Notes: Johnston et al. (2014) recommended using the generic name Blumeriella Arx over Phloeosporella because P. padi (Lib.) Arx was referred to as macroconidial morph of B. jaapii. In addition, B. jaapii is in common use for the widespread shot-hole disease on Prunus. However, there is no molecular data to prove Blumeriella and Phloeosporella are congeneric. Phloeosporella is a polyphyletic genus and a culture of its type species is not available (Quaedvlieg et al. 2013). Therefore, we accept Phloeosporella as the legitimate name.
Phloeosporella resembles Asteromidium, Diplosporonema, Stictosepta and Septocyta in having holoblastic, sympodial conidiogenous cells with 1–2, unthickened apical scars. Stictosepta and Septocyta have stromatic, pycnidial, convoluted conidiomata, which differ from the acervular conidiomata in Asteromidium Phloeosporella and Diplosporonema (Sutton 1980). Phloeosporella was separated from Asteromidium and Diplosporonema by its cylindrical to subcylindrical, 1–5-septate conidia.
Fourteen taxa are accepted in Phloeosporella (Index Fungorum 2019) and most of them are associated with leaf lesions on Fabaceae, Lamiaceae, Rhamnaceae, and Rosaceae (Sutton 1980).
Distribution: India, USA (Sutton 1980)
Phloeosporella ceanothi (redrawn from Sutton 1980) a Conidia. b Conidiogenous cells and developing conidia. c Vertical section of conidioma.
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.