Summary:
Features include 1) resupinate growth on bark or rotten wood of logs, 2) loosely adnate fruitbodies that are white to cream and have an indistinct margin, 3) spores that strongly amyloid, smooth, thick-walled, and elliptic to nearly round, 4) in most cases paraphysoids between basidia, and 5) monomitic context with clamped hyphae.

Microscopic:
SPORES varying in size but generally 9-11 x 5-7 microns, elliptic to nearly round, smooth, strongly amyloid, walls thick; BASIDIA "polymorphous, sometimes distinctly clavate, in some cases suburniform, mostly terminal but some lateral basidia present, usually 20-35 x 6-7 microns, with four sterigmata"; CYSTIDIA lacking "but in most specimens paraphysoid hyphae between the basidia"; HYPHAE monomitic; BASAL HYPHAE about 2-3 microns wide, "thin-walled, somewhat encrusted straight and uniform", SUBHYMENIAL HYPHAE more irregular, all hyphae with clamp connections, (Hjortstam)

Notes:
Amyloathelia amylacea has been found in BC, OR, ID, MB, ON, PQ, MI, MT, and VT, (Ginns). Collections were examined from BC, ID, ON, France, and Germany, (Hjortstam).

Synonyms and Alternate Names:
Lloydella sulcata (Burt) Lloyd
Stereum sulcatum Burt in Peck