Ceratosphaeria rhenana  

Stromata absent, though the ascomata are sometimes coalesced.

Ascomata 170-220µm diam, ± globose but often irregularly shaped, the body usually ± immersed, black; the neck cylindrical, to ca 500µm tall, black, often strongly oblique. Peridium dark brown, membranous, composed of several layers of mid-brown thin-walled textura angularis merging into hyaline inner layers, the cells of the neck region textura intricata, a few almost hyaline rhizoid-like hairs are often attached to the basal part of the ascoma. Interascal tissue composed of inconspicuous, very thin-walled paraphyses. Asci 130-164 x 5.5-7.5µm, cylindrical, long-stalked (often to almost half their length), rather thin-walled, often breaking off at the base, the apex ± truncate, with a conspicuous apical ring ca 3µm diam, 8-spored. Ascospores usually arranged uniseriately, 18-21.5 x (4-)5-6µm, narrowly fusiform, the ends acute, sometimes slightly curved, hyaline, thin-walled, becoming ± equally 3-septate, not constricted at the septa, with a single large guttule in each cell, without a mucous sheath.