E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
Features include 1) resupinate growth on wood, 2) a tomentose, separable fruitbody that is gray to dull buff, the surface papillose to colliculose, the margin and subiculum almost white, 3) spores that are mostly round to nearly round, aculeolate to echinulate, and brown, 4) subicular hyphae that are colorless to pale brown (some with yellow-brown contents), with frequent clamp connections, and 5) white cordons.

Tomentella cinerascens has been found in BC, WA, ON, AZ, MI, MT, NY, and SD, (Ginns), as well as Austria, Czechoslovakia, Denmark, Finland, France, Germany, Poland, Sweden, Algeria, and Turkey, (Larsen).

Fruiting body:
up to 0.03cm thick, separable, tomentose, somewhat arachnoid [cobwebby] when young, spore-bearing areas "at first discontinuous, becoming continuous in older specimens"; gray to dull buff; sometimes smooth, mostly papillose or colliculose, rarely granulose; "sterile margin fibrillose to mostly byssoid", much paler than spore-bearing areas, almost white; subiculum loose-fibrous, almost white; cordons obscure, white, (Larsen), spore deposit pale brown, (Buczacki)

Microscopic:
SPORES 5-6 microns in diameter, or 5-6 x 5 microns, mostly round to nearly round, sometimes irregular to irregularly round, "aculeolate to echinulate, walls hazel to dull brown"; BASIDIA 4-spored, 30-45 x 6.5-8 microns, clavate, sterigmata up to 5 microns long; SUBHYMENIAL HYPHAE 2.5-4 microns, colorless (parts sometimes green in KOH), thin-walled, with clamp connections; SUBICULAR HYPHAE 2.5-4(5) microns wide, walls colorless or light tan to pale brown (some with contents dull yellowish brown), thin-walled or with wall thickening slight, septate, with frequent clamp connections; CORDONS up to 90 microns wide, pale brown to almost colorless, individual hyphae 1.5-3 microns wide, thin-walled, with clamp connections, (Larsen)