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

Summary:
Features include flat growth on hardwood, a perennial yellowish brown to grayish brown pore surface that is woody and not readily separable, small circular pores, and microscopic characters including dextrinoid spores.

Gilbertson listed Fomitiporia punctata from 44 states and provinces in North America, including British Columbia, Washington, Oregon and Idaho, but described it as fruiting on hardwoods and conifers. Ginns(28) says that reports on conifers have been has been segregated under Fomitiporia tsugina, so that the range is uncertain but says that Fomitiporia punctata has occurred on the hardwood ornamental Juglans sieboldiana in BC.

Cap:
growing flat on wood with pore surface exposed, becoming widely spread out, woody, adnate; margin up to 2cm wide and yellowish brown, tomentose, "receding, becoming black and rimose", (Ginns), growing flat on wood with pore surface exposed, becoming widely spread out; woody, not readily separable; margin at first up to 2cm wide, yellowish brown, tomentose, receding, becoming black and cracked when older, (Gilbertson), up to 20cm long and 0.5-2.5cm thick, crustaceous, (Lincoff), forming patches several centimeters to decimeters across, growing flat on wood, up to 2cm thick, attached tightly, woody, hard; margin sterile, thin and distinctly bounded, whitish, (Breitenbach)

Flesh:
up to 0.2cm thick, "golden brown, becoming dark reddish brown", (Ginns), up to 0.2cm thick, "golden brown to dark reddish brown in older specimens", (Gilbertson)

Pores:
6-8 per millimeter, round, "edges thick, entire, minutely tomentose", pore surface yellowish to grayish brown, dull, smooth; tubes golden brown, each layer up to 0.6cm thick, (Ginns), 6-8 per mm, circular, walls thick and minutely tomentose, yellowish brown to grayish brown; dull, smooth; tube layers concolorous, single layers up to 0.6cm thick, (Gilbertson), cinnamon-colored or tobacco-colored with a grayish hazel pruinescence, tubes up to 0.7cm long, (Lincoff), 5-7 per mm, rounded to elongated, dull tobacco brown to chestnut brown; tube layer 0.1-0.3cm thick (tubes "1-3 mm long"), "distinctly layered in fruiting bodies several years old", (Breitenbach)

Odor:
none in particular (Lincoff)

Taste:
none in particular (Lincoff)

Microscopic:
spores 6.5-8.5 x 5.5-7.0 microns, nearly round to broadly elliptic, some dextrinoid, walls colorless, slightly thickened; cystidioles about 26 x 6 microns, "clavate with an attenuated finger-like apex"; generative hyphae 2.5-5.0 microns wide, walls colorless, thin to moderately thick, skeletal hyphae 2.5-5.0 microns wide, "walls dark brown, thin to thick", (Ginns), spores 6.5-8.5 x 5.5-7 microns, broadly oval to nearly round, smooth, dextrinoid, colorless; basidia 4-spored, 11-12.5 x 7-8.5 microns, broadly clavate, simple-septate at base; setae absent; thin-walled ventricose cystidioid elements present; hyphae of context of 2 types, mostly the first: 1) 2.5-5 microns wide, dark brown in KOH, thin-walled to thick-walled, rarely branched, occasionally septate, 2) almost colorless, thinner-walled; hyphae of trama similar, (Gilbertson), spores 7-8(9) x 6-7.5 microns, elliptic to nearly round, smooth, dextrinoid, some thick-walled, with droplets or granular contents; setae absent, (Breitenbach)

Spore Deposit:
white (Buczacki)