Ascomata perithecial, 100-160 µm diam, ± globose, minutely papillate, the ostiole periphysate; shining black, smooth- or faintly rough-walled; superficial or with the base immersed, scattered to densely aggregated 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 2.5 µm diam. Asci 44-52 x 4-6 µm, cylindrical, fairly long-stalked, thin-walled at all stages, the apex obtuse to rounded with an inconspicuous J- apical ring ca 2 µm diam and 0.5 µm thick, 8-spored. Ascospores arranged biseriately, 5.5-7 x 1.5-2 µm, ellipsoidal to cylindric-ellipsoidal, 1-septate (sometimes at a very late stage in spore development), hardly constricted at the septum, thin-walled, hyaline, smooth, without a gelatinous sheath or appendages.
Anamorph: Chloridium clavaeforme. Conidiomata absent. Conidiophores formed singly or in clusters from minute stromatic pads, 35-100 µm long, 2.5-4 µm diam at the base, dark brown, fairly thick-walled, paler at the tip, the apical cell becoming fertile, sometimes proliferating by growing through the conidiogenous cell. Conidiogenous cells 12-20 x 2-3 µm, morphologically similar to conidiophore cells but with a single terminal fertile locus, with a conspicuous protruding flared to cup-shaped collarette 2.5-4 µm deep, proliferating percurrently, sometimes from multiple loci within individual collarettes. Conidia 2.5-3 x 1.5-2.5 µm, obconical, the apex rounded to truncate, the base truncate, hyaline, aseptate, thin-walled, without setae, without mucous sheath or appendages.
The name C. myriocarpa has been conserved in the sense of Booth (1957); the original material in Fries's herbarium is referable to C. vermicularioides. See Constantinescu et al. (1995), Holm & Constantinescu (1996).