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

Summary:
Features include flat growth on dead Douglas-fir wood, cream to buff pores of irregular size, and microscopic characters that include distinctive contorted thick-walled hyphae in trama. The online Species Fungorum, accessed December 11, 2013 and April 18, 2020, gave the current name as Gilbertsonia angulopora but Mycobank, accessed on the latter date, listed it as Postia angulopora. The description is derived from Gilbertson(1) except where noted.

Postia angulopora has been found in BC and OR.

Cap:
up to 20cm, growing flat on wood with pore surface exposed, soft and fragile when fresh, hard and brittle when dry

Flesh:
subiculum less than 0.1cm thick, chalky and brittle; white to cream-colored

Pores:
pores highly variable, some over 1 mm and others up to 4 per mm, angular, with thin walls that become torn; cream to buff; tube layer up to 0.6cm thick, colored as pores or becoming pale buff

Microscopic:
spores 5.5-7 x 4-5 microns, broadly elliptic, smooth, inamyloid, colorless; basidia 4-spored, 25-40 x 7-10 microns, clavate, with basal clamp; cystidia absent; hyphae appearing dimitic, generative hyphae of trama 3-6 microns wide, thin-walled, some with frequent branching, with clamp connections, other hyphae in trama are thick-walled, firm-walled to almost solid, often contorted and lobed or branched, colorless, mostly 3-6 microns wide but with some inflated parts up to 10 microns wide, in lower subiculum and mycelial felts of decayed wood the thick-walled hyphae are more uniform, 2-4 microns wide, most with rare branching, (Gilbertson), generative hyphae 3-6 microns wide, binding hyphae of 2 types a) in the trama, 3-6 microns wide, some segments swollen to 10 microns wide, "contorted, frequently branched, the tips broadly rounded (not attenuated)", and b) in the context next to the tube layer and in mycelial felts in the wood, 2-4 microns wide, "infrequently branched, walls parallel, thick", (Ginns)