Summary:
Features include 1) resupinate growth on Oregon White Oak, 2) a membranaceous fruitbody that is smooth to colliculose, that is colored ochraceous with a yellow growing margin, and that has short hyphal strands, 3) cylindric smooth spores, 4) basidia that are stemmed and clavate, 5) hyphidia that are cylindric, colorless, and sometimes branched, and 6) hyphae that are colorless, thin-walled to somewhat thick-walled, and smooth or covered with acyanophilic warts, the hyphae without clamp connections.

Microscopic:
SPORES 12-15 x 4.5-6 microns, cylindric, smooth, slightly colored; no cystidia or gloeocystidia; IN SECTION "500 microns thick, chamois-colored, becoming stratose", the hyphae 3-3.5 microns wide, "suberect, densely arranged and interwoven, slightly colored, thin-walled, collapsing", "not incrusted, not nodose-septate", fruitbodies also referred to as composed of 3 strata, (Burt), SPORES 10-16.5 x 4.5-4.8 microns, cylindric, smooth, colorless, thin-walled; BASIDIA stemmed, clavate, 60-100 x 8-10 microns; HYPHIDIA 2-4 microns wide, cylindric, colorless, sometimes branched; HYPHAE 2-4 microns wide (locally inflated up to 7.5 microns wide), colorless, thin-walled to somewhat thick-walled, smooth or covered with acyanophilic warts, (Julich)

Notes:
Ramaricium flavomarginatum has been found in BC and WA (Ginns).