Chaetoseptoria Tehon, Mycologia 29(4): 444 (1937)
Ascomycota, genera incertae sedis
Parasitic on the host plant in terrestrial habitat. Sexual morph: undetermined. Asexual morph: Conidiomata brown, pycnidial, amphigenous, scattered to gregarious, immersed to semi-immersed, globose, unilocular, setose. Ostiole well defined, circular, centrally located. Conidiomatal setae brown, cylindrical to subulate, with obtuse apex, unbranched, sparsely septate, smooth-walled, restricted in ostiolar region. Conidiomatal wall composed of thick-walled, brown to hyaline cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells hyaline, enteroblastic, phialidic, cylindrical, ampuliform, determinate, smooth-walled, with a minute apical channel and collarette. Conidia hyaline, acicular, straight or slightly curved, 6–7-septate, smooth-walled, guttulate (Morgan-Jones et al. 1986).
Type species: Chaetoseptoria vignae Tehon, Mycologia 29(4): 444 (1937)
Notes: Chaetoseptoria shares similar morphology of conidia with Septoria and septoria-like fungi (Neoseptoria, Phlyctaeniella, Polyphialoseptoria, Ruptoseptoria, Sphaerulina), but can be distinguished from these genera by its setose conidiomata (Sutton 1980, Quaedvlieg et al. 2013). Three species are accepted in Chaetoseptoria, C. indica P.K. Khanna, C. vignae Tehon and C. wellmanii J.A. Stev., but none of them has been studied with molecular data. Chaetoseptoria wellmanii and C. vignae have been reported as a pathogen on Fabaceae (Phaseolus vulgaris, Vigna sinensis), causing round to irregular, brown or yellowish leaf spots (Tehon 1937, William 1956). Chaetoseptoria indica has been reported on decaying shoots of Bothriochloa pertusa (Poaceae) (Khanna 1966).
Distribution: Australia, Colombia, Mexico, New Zealand, Nigeria (William 1956, https://www.gbif.org/).
Chaetoseptoria vignae (redrawn from Morgan-Jones et al. 1972e) a Conidia. b Vertical section of conidioma. c Conidiogenous cells and developing conidia.
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