Summary:
Features include 1) resupinate growth on wood, 2) a cream to ochraceous fruitbody that is odontioid with apically fringed spines that are mostly flattened, but may be conic or subcylindric, incised or denticulate, 3) a variable margin that is often well demarcated with a whitish, narrow sterile zone, fringed under a lens, 4) spores that are elliptic, smooth, inamyloid, and colorless, 5) cystidial organs of 2 types: a) capitate hyphal ends with apical resinous encrustation, and b) sparse gloeocystidia, acute, with one or more constrictions, and 6) a monomitic hyphal system, the hyphae with clamp connections, the projecting hyphae in the tips of the spines generally tapering, with attached aggregated crystals.

Microscopic:
SPORES 4.5-5.5 x 3.5-4 microns, elliptic, smooth, thin-walled, with 1 to 3 droplets; BASIDIA 4-spored, at first subclavate, then subcylindric with suburniform constriction, 12-20 x 4-5 microns, with basal clamp connection; CYSTIDIAL ORGANS of 2 types: 1) sterile, capitate hyphal ends frequently occurring in the hymenium, 25-50 microns long to the most distal septum, with apical resinous encrustation, and 2) gloeocystidia, sparse in the hymenium, 20-35 microns long, acute, thin-walled, "with one or more constrictions and dense, strongly stainable protoplasm"; HYPHAE monomitic, distinct, somewhat thick-walled, 2.5-3.5 microns wide, richly branched, irregularly interwoven in the subiculum, arranged in parallel fashion in the spine trama, cyanophilic; projecting hyphae in the tips of the spines general tapering, with attached aggregated crystals, (Eriksson), SPORES 4.5-5.5 x 4-5 microns, broadly elliptic to nearly round, smooth, inamyloid, colorless; BASIDIA 4-spored, 15-17 x 4-5 microns, clavate, with basal clamp connection; CYSTIDIOLES up to 34 microns long and 4.5 microns wide, capitate, also some rare moniliform elements in hymenium, up to 30 microns long and 5 microns wide, staining brightly in phloxine; HYPHAE monomitic, subicular hyphae "thin to firm-walled", with clamp connections at all septa, often branched, 2.5-4 microns wide, (Gilbertson)

Notes:
Hyphodontia spathulata has been found in BC, MB, NB, NS, ON, PE, AZ, CO, FL, IA, IN, MD, MI, MN, NC, NM, NY, SC, and WI, (Ginns). Distribution includes AZ, MN, NY, Austria, Italy, Poland, Spain, Sweden, and Taiwan, (Langer), and Czechoslovakia (Eriksson).

Synonyms and Alternate Names:
Hymenochaete fimbriata Ellis & Everh.
Hymenochaete rugispora Ellis & Everh.