Summary:
Features include 1) resupinate growth on wood, 2) a waxy fruitbody that is whitish when young then pale buff to ochraceous, the surface smooth, the margin indistinct or sometimes more distinct and lighter in color, 3) spores that are suballantoid, smooth, and inamyloid, 4) cystidia that are usually numerous, awl-shaped, often with attached crystals or resinous apical globe, and 5) a monomitic hyphal system, the hyphae with clamp connections. The short, slightly thick-walled cystidia of P. phlebioides were used to distinguish it from P. subserialis, but this character is not consistent, and interfertility tests support the synonymy (Nakasone). Eriksson(6) says that P. phlebioides superficially resembles P. subserialis in the shape of cystidia and spores, but with a more gelatinous fruitbody.

Microscopic:
SPORES 6-7(8) x 2-2.5 microns, suballantoid, smooth, inamyloid, acyanophilic, thin-walled; BASIDIA 25-30(40) x 4-5 microns, "clavate, sometimes slightly constricted", usually with 4 sterigmata and with basal clamp connection; CYSTIDIA as a rule numerous, subulate [awl-shaped], 40-50(70) x 3-4 microns, "often with attached crystals or an apical globe of resinous matter, which easily falls off in microscopical preparations and are therefore best studied in living material under the lens (50 x or more)"; HYPHAE monomitic, 2-4 microns wide, with clamp connections and with thin walls "or in the basal part somewhat thickened walls", "subhymenial hyphae vertical, densely united, in old fruitbodies stratified", "basal hyphae mainly horizontal, as a rule forming a thin subiculum"; "tissue more or less filled with a grainy encrustation and often large KOH-crystals", (Eriksson), SPORES 5-7 x 1.5-2 microns; smooth, inamyloid, colorless, acyanophilic; BASIDIA 4-spored, 25-35 x 5-6 microns, clavate; CYSTIDIA 45-60 x 4-5 microns, cylindric, tapering toward apex, thin-walled, smooth; HYPHAE monomitic, subicular hyphae 3-6 microns wide, thin-walled to slightly thick-walled, nodose-septate, gelatinized, (Nakasone)

Notes:
Phlebia subserialis has been found in BC (including P. phlebioides), WA, ID, AB, NB, NT, ON, PQ, AZ, CO, FL, MS, MT, NM, NY, and WI, (Ginns). Distribution includes Denmark, Finland, France, Norway, Sweden, and Russia (Siberia), (Eriksson).

Synonyms and Alternate Names:
Poria attenuata var. subincarnata Peck
Poria subincarnata (Peck) Murrill