Summary:
Features include an annual, dark brown to almost black, semicircular cap that appears velvety at first and is often zoned and wrinkled, at first exuding resin, and a white pore surface when fresh that turns dark quickly when touched. The rotted wood has an anise odor. The description is derived from Gilbertson(1) except where noted. Some authors (Breitenbach(2), Lincoff(2), but not Gilbertson(1)) separate Ischnoderma benzoinum growing on conifers and with darker flesh and tubes from Ischnoderma resinosum growing on hardwoods.

Chemical Reactions:
flesh darker with KOH (Lincoff)

Odor:
the rot has a strong anise odor, (Gilbertson), aromatic when fresh, exposed wood sometimes with anise odor, (Trudell)

Microscopic:
spores 5-7 x 1.5-2 microns, cylindric, inamyloid, colorless, thin-walled, illustrated as smooth; basidia 4-spored, 12-18 x 4.5-6 microns, clavate, with basal clamp; hyphal system dimitic: generative hyphae in cap tomentum 4-10 microns, brownish, tortuous, very thick-walled, moderately branched, with a few large scattered clamp connections, in the context dominated by the same type but colorless, more frequently clamped, and in parts swollen up to 12 microns wide (in KOH), in subhymenium 3-5 microns wide, straighter and with slightly thickened walls, skeletal hyphae "partly mixed with the generative hyphae in the context, straight or slightly flexuous, very thick-walled and without sidebranches, 3-10 microns in diameter, whether they are long segments of sclerified generative hyphae or not is difficult to decide, as few clamps were observed in these hyphae, distinctive skeletal hyphae observed only in the trama, straight, thick-walled to solid and light yellowish at maturity, 3-10 microns in diameter"

Spore Deposit:
white (Phillips, Arora)

Notes:
Ischnoderma resinosum has been found in BC, WA, OR, ID, MB, ON, PQ, AK, AR, AZ, CA, CO, CT, DE, FL, IA, IL, IN, KS, KY, MA, MD, ME, MI, MN, MO, MT, NC, NE, NJ, NY, OH, PA, RI, TN, VA, VT, WI, and WV, and it is circumglobal through Northern Asia to West Europe, (Gilbertson).

EDIBILITY

no (Phillips), said to be edible when young and watery (Arora)

Synonyms and Alternate Names:
Polyporus benzoinus Wahlenb.: Fr.
Polyporus fuliginosus Scop.: Fr.
Polyporus resinosus Fr.
Tuber giganteum Gilkey