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Family: ChaetosphaeriaceaeGenus: Chaetosphaeria
Ascomata 150-200 µm diam, globose or slightly oblate, minutely papillate, the ostiole periphysate; shining black, smooth-walled; superficial or with the base immersed, scattered amongst setae and conidiophores. Peridium composed of an outer layer of dark brown thick-walled cells intermediate between textura angularis and intricata with cells to 3 µm diam, often completely occluded with melanin, and an inner layer of thin-walled flattened hyaline angular cells. Interascal tissue composed of copious persistent tapering thin-walled simple paraphyses to 4 µm diam, sometimes significantly longer than the asci. Asci 68-82 x 7-8 µm, cylindrical, fairly long-stalked, thin-walled at all stages, the apex obtuse with an inconspicuous J- apical ring ca 2 µm diam and 0.5 µm thick, 8-spored. Ascospores arranged biseriately, 12.5-15 x 3-4 µm, fusiform to ovoid-fusiform, 1-septate from an early stage, hardly constricted at the septum, thin-walled, hyaline, smooth or slightly roughened, without a gelatinous sheath or appendages.
Anamorph: Chloridium pachytrachelum. Conidiomata absent. Conidiophores formed singly or in clusters from minute stromatic pads, 60-250 µm long, 3.5-6 µm diam at the base, mid brown, fairly thick-walled, paler at the tip, the apical cell becoming fertile, sometimes proliferating by growing through the conidiogenous cell. Conidiogenous cells 7-20 x 3-4 µm, morphologically similar to conidiophore cells but with a single terminal fertile locus, with a conspicuous protruding cup-shaped collarette, proliferating percurrently. Conidia 4-9 x 2-3.5 µm, ± ellipsoidal, occasionally reniform, the apex and base obtuse, hyaline, aseptate, thin-walled, without setae, without mucous sheath or appendages.