Nova Acta R. Soc. Scient. Upsal. ser. 3, 13: 93 (1885).

Basionym: Collema nodulosum Nyl., Acta Soc. Linn. Bordeaux 21: 266 (1857).

Protolog: Gallia, Mende, Prost (H-NYL 42452-lectotype; H-NYL 42451-isolectotype). Lectotypified by Henssen & Jørgensen (1990: 138).

Type locality: France, Region Occitanie, Department Lozère, Mende, 750 m, s.d., Prost (H-NYL 42452 - lectotype; H-NYL 42451 - isolectotype).

Type locality coordinates: 44°31'9.84"N, 3°30'5.04"E; 44.5194, 3.5014.

Molecular barcode: Data lacking.

Thallus: black, cushion-like, diameter 3-4 mm, composed of small, nodulose-, globose- or club-like, + pruinose lobes. Rhizohyphae tufted. Apothecia present, diameter up to 0.5 mm, + sunken into the lobes, disc red-brown, thalline exciple very thin. Spores ellipsoid, unicellular, 8 per ascus, 10 - 13 / 6 - 9 µm (Czeika et al. 2004: 184).