Summary:
Piptoporus betulinus forms a kidney-shaped to round, whitish to brownish bracket with a curb-like extension of margin below the level of the pore surface. It is found only on birch and is common in that habitat. |The current name in the online Species Fungorum accessed May 3, 2020 was Fomitopsis betulina, but MycoBank, accessed the same day, gave the current name as Piptoporus betulinus. |It has been used as tinder, as a razor strop, and as an anesthetic, (Phillips). According to Ginns(28) the medicinal properties attributed to it include boosting the immune system and actions against inflammation, viruses, and bacteria. |There is interesting speculation about why the ''Iceman'' was carrying pieces of Piptoporus betulinus: "Among the numerous items of equipment with the ''Iceman'', who died more than 5000 years ago on an alpine glacier, were three fungal objects : two different shaped fruitbody pieces of the polypore Piptoporus betulinus, each mounted separately on a leather thong, and, found in his girdle bag, a relatively large quantity of tinder material prepared from the ''true tinder bracket'' Fomes fomentarius. A full description of these items and a chronological report on their identification is given. The question about the possible use of the fungi is discussed on the basis of a comprehensive collection of ethnomycological and pharmacological literature data." (Peintner(5) with Latin names italicized).

Odor:
strong and pleasant, (Phillips), none (Lincoff(1)), pleasant (Breitenbach)

Taste:
slightly bitter (Phillips), bitterish (Lincoff(1)), somewhat sour and bitter (Breitenbach)

Microscopic:
spores 5-6 x 1.5-1.7 microns, cylindric, slightly curved, smooth, inamyloid, colorless; basidia 4-spored, 10-12 x 5-6 microns, clavate, with basal clamp; cystidia absent; hyphal system di-trimitic, generative hyphae in context 2.5-4 microns wide, colorless, thin-walled, with clamp connections, rarely branched, skeletal hyphae of context 2.5-5 microns wide, colorless in KOH, "thick-walled, nonseptate, some much branched, others with rare or occasional branching", hyphae of trama similar, (Gilbertson), spores 3-6 x 1.5-2 microns, cylindric to sausage-shaped, smooth, (Arora)

Spore Deposit:
white (Arora)

Notes:
Piptoporus betulinus has been found in BC, WA, ID, AB, MB, NB, NS, NT, ON, PE, PQ, SK, YT, AK, CT, IA, KS, MA, ME, MI, MN, MT, NC, NH, NJ, NY, PA, TN, VT, WI, and WV, and circumboreally, (Gilbertson). It also occurs in Europe and Asia (Breitenbach).

EDIBILITY

no (Phillips), edible when young according to McIlvaine, but tough, (Arora)

Synonyms and Alternate Names:
Peziza badioconfusa Korf
Polyporus betulinus Bull.: Fr.