Summary:
Features include minute, pulvinate, gelatinous, dark brown to black, wrinkled fruitbodies, growing on the lichen Mycoblastus fucatus, identified by microscopic characters including long epibasidia and spur-like clamp connections on the basidial base. The dark color results from the presence of greenish-colored host hyphae intermixed with the hyphae of the fungus.

Microscopic:
spores 7-11 x 7-9.5 microns, nearly round, with distinct apiculus; 4-spored basidia dominant in North American collections, all 2-spored in European collections, basidia when mature 16-23 x 10-19 microns, subglobose, with 1-3 longitudinal septa, epibasidia 2-4.5 microns wide, reaching more than 100 microns long, subcylindric; hymenium colorless or greenish, containing numerous probasidia, probasidial initials ellipsoid, with a basal clamp connection, clamp connection "often spur-like on the basidial base without being attached to the subtending hypha"; hyphidia and cystidia absent; hyphae of context 1.5-2.5 microns wide, thick-walled, with clamp connections, fertile hyphae 3-6 microns wide, thick-walled, haustorial branches frequent, tremelloid, mother cell 3-4 x 2-3 microns, ellipsoid to subspherical, haustorial filaments 0.5-0.8 microns wide, "growing indefinitely, often branched, sometimes more abundant than context hyphae", anamorph "long irregular conidial chains are sometimes present in the hymenium", in addition, elongate ellipsoid conidia, 4-8 x 2-4 microns, are often observed in the hymenium

Notes:
The distribution includes BC, WA, Austria, Belgium, Denmark, France, Germany, Luxembourg, Norway, Spain, Sweden, Switzerland, and United Kingdom, (Diederich),

Synonyms and Alternate Names:
Corticium subsulphureum P. Karst.
Peniophora subsulphurea (P. Karst.) Hoehn. & Litsch.