Summary:
Features include 1) resupinate growth on wood, soil, or sometimes rock, 2) a mould-like, dark brown to reddish brown fruitbody, often with a slight vinaceous tint, the surface smooth to irregularly tuberculate, the subiculum thin, paler, the sterile margin narrow, fibrillose to villose, colored as subiculum, 3) spores that are irregularly round to somewhat round, often flattened on one side, aculeolate to echinulate, and brown, 4) basidia that are distended, 60-90 x 9-14 microns, up to 20 microns wide 10-15 microns above the basal septa, often with transverse septa, 5) subhymenial hyphae that are dull brown near the subiculum, paler toward hymenium, with frequent clamp connections, this layer containing what appear to be aborted basidia, 6) subicular hyphae that are pale yellowish brown, with frequent clamp connections.

Microscopic:
SPORES 6-7(8.5) microns, irregularly round to somewhat round, often flattened on one side, "aculeolate to echinulate, pale tan to yellowish brown"; BASIDIA 4-spored, 60-90 x 9-14 microns, up to 20 microns wide 10-15 microns above the basal septa, often with transverse septa, with clamp connection at base; SUBHYMENIAL HYPHAE 3-5 microns wide, dull brown near subiculum and paler toward hymenium, "thin-walled or with some wall thickening (walls becoming thinner towards the hymenium)", septate, with frequent clamp connections, this layer containing what appear to be aborted basidia, giving vertical sections a layered appearance; SUBICULAR HYPHAE 2.5-4(5) microns wide, pale yellowish brown, wall thickening apparent, septate, with frequent clamp connections; CORDONS infrequent, up to 40 microns wide, dark brown, individual hyphae 2-4.5 microns wide, with clamp connections, (Larsen), SPORES 6-8 microns in diameter (excluding spines), irregularly subglobose, spiny, brown; BASIDIA 4-spored, 60-90 x 10-20 microns, with basal clamp connection; CYSTIDIA none, but "in hymenium with many ventricose-clavate elements"; HYPHAE monomitic, 4-5.5 microns wide, brownish, thin-walled to thick-walled, septa with clamp connections, CORDONS up to 50 microns wide, dark brown, (Breitenbach)

Notes:
Tomentella terrestris has been found in BC, ID, NS, ON, AZ, FL, MI, MT, NC, NM, and NY, (Ginns). It also occurs in Czechoslovakia, France, Germany, Sweden, and the United Kingdom, (Larsen).