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

Summary:
Features include 1) resupinate growth on hardwood, 2) a membranous fruitbody that is whitish, later cream to ocherish, and smooth to somewhat tuberculate when fresh, 3) a margin that is whitish, fibrillose and sometimes has fine rhizomorphs, as well as larger rhizomorphs on the underside of the bark it is growing on, 4) a subiculum that is cottony and white, with rhizomorphs, 5) spores that are elliptic, smooth, inamyloid, and colorless, 6) absent cystidia, and 7) a monomitic hyphal system, the septa without clamp connections except sometimes scattered single to multiple clamp connections in the subiculum.

Phanerochaete tuberculata has been found in BC, ON, AZ, CO, MI, MN, PA, and WI, (Ginns). It has also been found in Europe including Switzerland (Breitenbach). It is rather common in south Scandinavia, north to central Finland, (Eriksson). It occurs also in Estonia and France, (Burdsall).

Fruiting body:
resupinate, attached +/- tightly to substrate, forming patches up to about 0.05cm thick and several centimeters across, consistency wax-like and soft; white when young, later cream to ocherish; "smooth to somewhat verrucose when fresh", smooth and somewhat fissured when dry; "margin whitish to white, filamentous and sometimes with fine rhizomorphs", (Breitenbach), resupinate, effused [spread out], "confluent and sometimes becoming very large, covering the underside of trunks and branches", generally 0.01-0.05cm thick, adnate [firmly attached]; "at first white then turning creamish or when old darkening to pale ochraceous"; when fresh more or less tuberculate, becoming smoother on drying, "dry old fruitbodies more or less cracked"; "margin varying, often at least partly fibrillose, small rhizomorphs sometimes present in the periphery" and larger ones on the underside of the bark on which it grows, (Eriksson), effused [spread out], up to 4cm x 2cm, up to 0.03cm thick, membranous, adherent, continuous, "initiated on cordons and then filling in between"; pale cream, not changing in KOH; smooth; "margin fibrillose to cordonic, white", subiculum byssoid [cottony], white, thin, with cordons, (Burdsall), spore deposit white (Buczacki)

Microscopic:
SPORES 5-6.5 x 2.8-4 microns, elliptic, smooth, inamyloid, colorless, some with droplets; BASIDIA 4-spored, 30-35 x 5-6.5 microns, narrowly clavate, without basal clamp connection; CYSTIDIA not seen; HYPHAE monomitic, 2-5 microns wide, colorless, thin-walled to thick-walled, septa without clamp connections, sometimes with scattered clamp connections in the subiculum, (Breitenbach), SPORES 5-6.5 x 3-4 microns, elliptic, smooth, inamyloid, acyanophilic, thin-walled, "with oily plasmatic contents"; BASIDIA 4-spored, 25-35 x 4-5 microns, clavate - subclavate, without basal clamp connection; CYSTIDIA none; HYPHAE monomitic, with thin or slightly thickened walls; subhymenial hyphae 2-3 microns wide, in a dense context; subicular hyphae 3-5 microns wide, "more or less parallel to the substrate and sparsely branched into an open texture", clamp connections "sometimes present on the subicular hyphae, rarely in pairs", (Eriksson), SPORES 5.5-7 x 3.5-4.5 microns, broadly elliptic, adaxially flattened, smooth, inamyloid, acyanophilic, colorless, thin-walled; BASIDIA 4-spored, 33-48 x 6-7 microns, clavate to broadly clavate, colorless, thin-walled, sterigmata up to 4 microns long; CYSTIDIA none; HYPHAE monomitic, SUBHYMENIUM a compact textura intricata, hyphae 3-4 microns wide, frequently branched, often candelabrate at bases of basidia, colorless, smooth, thin-walled; SUBICULUM a textura porrecta, hyphae 5-8 microns wide, "infrequently branched, branches at nearly right angles", colorless, smooth, "thin-walled or with slight wall thickening", mostly simple-septate, "with rare single and multiple clamp connections"; CORDONS up to 500 microns wide, rind not differentiated, hyphae a textura porrecta, "hyphae like those of subiculum", (Burdsall)