TYPE. CANADA. ONTARIO, Renfrew County, Petawawa Forest Experiment Station, not far from Mill Lake. On trunk of Picea in a swamp. 21.VIII.1972, L. Tibell 4638 (FH 00390457, isotype).
Description. Lichenized fungus.
Thallus crustose, thin, grey to greenish grey, verrucose or ± endosubstratic. Photobiont trebouxoid alga. Ascomata stalked capitulate mazaedia, 0.5-0.8 mm, 6-8 times as high as width of stalk, black, shiny, I–, sometimes with a thin, white pruina at the edge of the exciple; capitulum 0.12-0.4 mm diam., lens-shaped; stalk 0.08-0.12 mm diam. Asci clavate, 8-spored. Ascospores brown, 2-celled, constricted at septum and with irregular cracks on the surface, 8-11 × 3.5-5 µm. Pycnidia frequent; conidia 2-3 × 1-1.5 µm, ellipsoid.
Substrate and Habitat. Lignicolous and corticolous on conifers in forests and pinewoods.
Distribution. Europe and North America; in North Carolina found in the Blue Ridge ecoregion.
Giavarini, V.J. & O.W. Purvis. (2009) Calicium Pers. (1794). Pp. 241-245 in Smith, C.W., A. Aptroot, B.J. Coppins, A. Fletcher, O.L. Gilbert, P.W. James & P.A. Wolseley (eds.). 2009. The Lichens of Great Britain and Ireland. The British Lichen Society, London.
Tibell, L. (1975) The Caliciales of boreal North America. Taxonomy, ecological and distributional comparisons with Europe, and ultrastructural investigations in some species. Symbolae Bot. Upsaliensis21(2): 1-128 (original description).