Summary: Features include flat growth on wood with the ivory yellowish or tan pore surface exposed, a soft whitish margin up to 0.2cm wide, firm attachment, tough consistency, distinctly stratified tube layers, black flecks in the rotted wood, and microscopic characters including broadly elliptic, non-truncate spores, slender branched dextrinoid binding hyphae and wider, dextrinoid, rarely branched skeletal hyphae.
Taste: mild or slightly acid (Gilbertson)
Microscopic: spores 4.5-7.5 x 3-5 microns, oval to broadly elliptic, smooth, inamyloid, colorless, thin-walled, distinctly apiculate, usually with a single droplet; basidia 4-spored, 20-40 x 5.5-8.5 microns, clavate, with basal clamp, some basidia with narrowed base; cystidia none, cystidioles embedded or projecting slightly, 13-35 x 4.5-6 microns, fusoid, with basal clamp, some lightly incrusted; hyphal system trimitic: subiculum generative hyphae 2-3 microns wide, thin-walled, with clamp connections, inconspicuous, skeletal hyphae 2.5-7 microns wide, thick-walled, nonseptate, rarely branched, binding hyphae 1-2 microns wide, some branched profusely, nonseptate, trama hyphae similar, skeletal and binding hyphae dextrinoid, (Gilbertson)
Spore Deposit: white (Phillips)
Notes: Perenniporia subacida has been found in BC, WA, OR, ID, NB, NF, ON, PQ, AK, AL, AR, AZ, CA, CO, FL, KS, KY, LA, MA, MN, MO, MT, NC, NM, NY, SC, TN, VA, WV, and WY, (Gilbertson).
Habitat and Range
SIMILAR SPECIES
The rotted wood with black flecks is similar to the decays caused by Heterobasidion annosum group and Junghuhnia zonata, (Ginns(28)). See also SIMILAR section of Perenniporia medulla-panis.
Habitat
perennial, mainly on conifers, causing butt rot in fir and hemlock, and common on dead fallen trees in many areas, also not infrequent on dead hardwoods; causes "feather rot", a white stringy rot of dead conifers and hardwoods and also a butt and root rot of living conifers, "cream to golden yellow mycelial felts develop in the decayed wood", (Gilbertson)