Summary:
Many if not most mycologists consider this to be the same species as Mollisia cinerea, in which case Mollisia cinerea is the correct name, Mollisia being conserved against Tapesia. Features include a minute, urn-shaped to saucer-shaped, blue-gray to ocher-gray fruitbody resting on a network of brown filaments on bark and rotting wood, and microscopic characters.

Microscopic:
spores 8-12 x 1.8-2.2 microns, cylindric-fusiform [cylindric - spindle-shaped], smooth, colorless, without drops or septa, biseriate; asci 8-spored, 45-50 x 5-7 microns, positive reaction to iodine; paraphyses filiform [thread-like], sometimes septate, with slight clavate widening toward tip; subiculum of hyphae 4-7 microns wide, dark brown, multiply septate, thick-walled, (Breitenbach), spores 12-14 x 2-3 microns, fusoid, usually simple but occasionally doubtfully 1-septate; asci 8-spored, reaching a length of 55-68 microns and a width of 6-8 microns, fusoid-clavate; paraphyses filiform, 2-4 microns wide, (Seaver)

Notes:
Tapesia fusca is found from NY to OR and NC, and is probably widely distributed, (Seaver). It is also found in Europe including Switzerland (Breitenbach). It has been reported from BC by O. Ceska (pers. comm.).

Synonyms and Alternate Names:
Hypochnus chaetophorus Hoehn. Mushrooms (Syracuse):
Mollisia fusca Karst.
Peniophora chaetophora (Hoehn.) Hoehn. & Litsch.
Tapesia cinerella Rehm
Tapesia griseopulveracea Sacc.
Tapesia rhois Fairm.
Tapesia subiculata Sacc.
Tapesia vincta Sacc.