Symb. Bot. Upsal., 21, 2: 45, 1975. Basionym: Lichen debilis Turner & Borrer ex Sm. in Smith & Sowerby - Engl. Bot., 35: tab. 2462, 1813.
Synonyms: Calicium norvegicum Vain. ex Hav.; Chaenothecopsis elevata (Vain.) Tibell
Distribution: N - Frl (Puntillo & Puntillo 2009), TAA (Nascimbene & al. 2021). C - Abr (Puntillo & Puntillo 2009), Mol (Nimis & Tretiach 1999, Caporale & al. 2008), Sar (Puntillo & Puntillo 2009). S - Bas (Puntillo & al. 2012), Cal (Puntillo 1994, 1996, Puntillo & Puntillo 2009).
Description: Thallus not evident, not lichenized, saprobic. Apothecia long-stalked, pin-like, 0.7-1,2 mm high. Stalk black, the central part formed by pale, mostly periclinally arranged hyphae, the outer part reddish or reddish brown, formed by strictly periclinally arranged hyphae. Capitulum lenticular, 0.2-0.4 mm across, black but sometimes with white, cottony hyphae on lower side, with a more or less well-developed excipulum of several layers of reddish brown, periclinally arranged hyphae. Epithecium brown to reddish brown; mazaedium not present; hypothecium brownish or faintly greenish brown. Asci 8-spored, cylindrical, with a thickened apex penetrated by a narrow canal, formed singly, persisting until the spores are mature. Ascospores 1-septate, the septum distinct, medium brown, ellipsoid, 7-9 x 2.5-3 µm, with a smooth or minutely areolate wall. Pycnidia black, subglobose or usually elliptical and orientated along the fibres of the wood. Conidia hyaline, curved, 3-6 x c. 1 µm. Photobiont absent. Spot tests: epithecium, excipulum and hypothecium K- or K+ greyish red, N+ more intensely red. Chemistry: a reddish unidentified pigment in the ascomata, sometimes in very low concentrations.
Note: on dry and weathered lignum of deciduous trees (Populus, Fraxinus, Ulmus), more rarely on conifers, in open situations, often in hollows of the trunks in species-poor stands; probably overlooked and more widespread, but never common.