Summary:
Features include stemless growth on aspen, a yellowish brown upper surface that is tomentose at first, yellowish brown flesh with a hard granular core that has flecks of white tissue, a yellowish brown pore surface, and microscopic characters including the absence of setae.

Microscopic:
spores 5-6 x 3.5-4 microns, oval to broadly elliptic, often flattened on one side, smooth, inamyloid, pale golden brown; basidia 4-spored, 14-16 x 5-6 microns, clavate, simple-septate at base; setae or other sterile hymenial elements absent; context hyphae from fibrous context of two types, some 3-7 microns wide, "pale yellowish and thin-walled to dark reddish brown and thick-walled, simple-septate, rarely branched, with parallel arrangement", these bound together by hyphae 2-4 microns wide that are pale to dark brown, much branched, thin-walled to thick-walled, simple-septate, trama hyphae similar to those of fibrous context, mostly pale brownish and thin-walled, 3-6 microns wide, hyphae of granular core of two types: some 2-3 microns wide, pale yellowish, much branched, simple-septate, and others up to 10 microns wide, dark reddish brown, thick-walled, contorted or lobed, (Gilbertson), spores 6-7.5(8) x 3.5-4.5 microns, elliptic, smooth, brown, thick-walled, (Breitenbach)

Spore Deposit:
rusty brown (Gilbertson)

Notes:
Inocutis rheades has been found in BC, ID, NB, NS, NWT, PQ, MN, and MT, (Gilbertson), and Europe, (Breitenbach).

Synonyms and Alternate Names:
Fomitopsis annosa (Fr.) P. Karst.
Polyporus annosus Fr.