Summary:
Features include 1) resupinate growth on wood or on rock, 2) a mould-like, mealy-velvety, or furfurescent fruitbody, mostly adherent, the mostly discontinuous spore-bearing surface colored pale yellowish brown, smooth or minutely punctate or granulose, the margin cottony to fibrillose, paler, the subiculum also paler, 3) spores that are irregularly round to irregular, aculeolate to echinulate, and brown, 4) basidia that are distended up to 20 microns wide, 5) subhymenial hyphae that are thin-walled, colorless to pale yellow or brown, with clamp connections, 6) subicular hyphae with wall thickening, that are brown to yellowish brown, with frequent clamp connections.

Microscopic:
SPORES 6-8(9) microns in diameter, or 7-10(11) microns across, irregularly round to sometimes irregular, aculeolate to echinulate, pale brown to umbrinous; BASIDIA 4-spored, 60-80 x 10-15 microns, up to 20 microns wide 10-15 microns above the basal septa, colorless or somewhat umbrinous, with clamp connection at base, sterigmata up to 6 microns long; SUBHYMENIAL HYPHAE 3-5 microns wide, colorless to pale yellow, often umbrinous, thin-walled, with clamp connections, "(this stratum also contains elements that appear to be basidia that have failed to mature)"; SUBICULAR HYPHAE 3-4.5(6) microns wide, brown to yellowish brown, wall thickening apparent, septate, with clamp connections frequent, (Larsen)

Notes:
Tomentella nitellina has been found in WA, BC, NS, ON, and NC, (Ginns), and also in France (Larsen).