E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
Features include 1) resupinate growth on wood and organic debris, 2) a form consisting of soft thin whitish to ocher patches, with a sharply bounded to fringed margin, 3) spores that are broadly elliptic, smooth, inamyloid, and colorless, 4) basidia that are 4-spored or 2-spored, and 5) a monomitic hyphal system, the hyphae with a central pore visible in the hyphal septa, but lacking clamp connections.

Athelia decipiens has been found in BC, WA, ID, AB, MB, NS, ON, PQ, AZ, CA, CO, IL, ME, NH, NJ, NM, NY, PA, and UT, (Ginns), and Austria, Belarus, Czechoslovakia, Estonia, Finland, France, Germany, Latvia, Norway, Sweden, United Kingdom, Turkey, and the USSR, (Julich).

Fruiting body:
resupinate, forming thin, membranous patches several centimeters across, soft in consistency, tightly appressed to substrate; whitish to cream to ocher; "smooth to slightly tuberculate, somewhat fissured when dry"; "margin sharply bounded to fringed", (Breitenbach), "thin, white, and pellicular", (Eriksson), spore deposit white (Buczacki)

Microscopic:
SPORES 4.5-5.5 x 3-3.5 microns, broadly elliptic, smooth, inamyloid, colorless, thin-walled; BASIDIA mostly 2-spored, 22-25 x 5-6 microns, clavate to ventricose; CYSTIDIA not seen; HYPHAE monomitic, with hyphae 2.5-5 microns wide, colorless, "not or only slightly incrusted, septa without clamps but with distinctly visible central pore", (Breitenbach), SPORES 4.5-5.5(6) x 3-3.5 microns, elliptic to ovate, often glued together in groups of 2 or 4; BASIDIA about 12-15 x 5 microns, "the sub-basidial cells often somewhat widened or swollen because of sidebranches developing from them"; HYPHAE monomitic 3-5 microns wide, without clamp connections, often with a grainy encrustation, (Eriksson), SPORES 5.5-6 x 3-3.8 microns; BASIDIA usually 4-spored, more rarely 2-spored, 10-14 x 5-6 microns; hyphae with central pore of septa mostly distinctly visible, (Julich)