Summary:
Features include 1) resupinate growth on wood, 2) fruitbodies that are thin, fibrous-cottony-membranous, brown to olive-brown, and tightly attached, the margin lighter in color and fringed with fine rhizomorphs, 3) spores that are elliptic to oval, smooth, inamyloid, and light brown, 4) cystidia that are cylindric, multiply septate, and irregularly encrusted, and 5) a monomitic hyphal system, the hyphae having scattered clamp connections. Luther(4) advises looking under a dissecting scope to find suitable areas to search for cystidia under the compound microscope.

Microscopic:
SPORES 8-10.5 x 4.5-5.5 microns, elliptic to oval, smooth, inamyloid, light brown; BASIDIA 4-spored, 30-45 x 6-7 microns, narrowly clavate, without basal clamp connection; CYSTIDIA 100-200 x 10-15 microns, cylindric, "thick-walled, multiply septate, tip blunt to somewhat widened, irregularly incrusted" (in illustration the encrustation not just at tip); HYPHAE monomitic 4-8 microns wide, brown, thin-walled, scattered septa with clamp connections, (Breitenbach)

Notes:
Coniophora olivacea has been found in BC, WA, OR, ID, MB, NS, ON, PQ, SK, YT, AL, AZ, CA, CO, GA, IA, LA, MA, MD, ME, MN, MO, MT, NC, NH, NJ, NM, NY, OH, PA, SC, VT, and WV, (Ginns). It has also been found in Europe (including Switzerland), and Asia, (Breitenbach).

Synonyms and Alternate Names:
Endogone lanata Harkn.
Endogone rosea Zeller