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

Summary:
Features include 1) resupinate growth on wood, 2) a spongy-membranous, tomentose fruitbody that is smooth to somewhat tuberculate and tan to pale yellow-brown, orange-brown, or lavender-brown, the margin lighter to whitish, the subiculum slightly paler than the spore-bearing surface, and fine rhizomorphs present, 3) spores that are mostly round, often appearing roughly triangular when immature, warted or spiny, the warts normally bifurcate, the walls nearly colorless to pale yellow or pale tan, 4) basidia often with median simple septa, and 5) a dimitic hyphal system, the hyphae without clamp connections.

Pseudotomentella mucidula has been found in BC, WA, ID, AB, ON, AZ, NM, and NY, (Ginns), Austria, Czechoslovakia, Denmark, Finland, France, Germany, Portugal, and Sweden, (Larsen), and Switzerland and Asia, (Breitenbach).

Fruiting body:
annual, resupinate, effused up to 20cm x 7cm, up to 0.05cm thick, "adherent to somewhat separable, cracking slightly, tomentose, rarely pelliculose"; spore-bearing area continuous when mature, tan to pale lavender-brown, smooth; sterile margin paler, almost white; subiculum paler than spore-bearing area, (Larsen), resupinate, attached loosely, forming spongy-membranous patches about 0.05cm thick and several centimeters across, spongy, soft; ocher-brownish to yellow-brownish or orange-brownish, smooth to somewhat tuberculate, dull; margin lighter to whitish, finely fringed with fine rhizomorphs; subiculum colored as the spore-bearing area, (Breitenbach), spore deposit white (Buczacki)

Microscopic:
SPORES 7-11 microns in diameter, mostly round, frequently appearing roughly triangular when immature, "normally warted or sometimes echinulate, the warts normally bifurcate", walls nearly colorless to pale yellow or pale tan; BASIDIA 4-spored, 35-45(50) x 7-9 microns, spheropedunculate to napiform [turnip-shaped] when immature, clavipedunculate when mature, "simple-septate at the base, often with median simple septa", sterigmata up to 8 microns long; HYPHAE dimitic; SUBHYMENIAL HYPHAE 2-3 microns wide, pale brown to nearly colorless, thin-walled, simple-septate; SUBICULAR HYPHAE of two types 1) generative, 2-3 microns wide, pale brown, with wall thickening apparent, simple-septate, 2) skeletal, 1-2(2.5) microns wide, yellowish, thick-walled, simple septa rare; CORDONS up to 20 microns wide, yellowish brown, the individual generative hyphae 1.5-2.5 microns wide, thin-walled, simple-septate, (Larsen), SPORES 6-9 microns excluding warts, nearly round, verrucose to spinose, some warts dichotomously forked, yellow-brown; BASIDIA 4-spored, 40-60 x 7-10 microns, narrowly clavate, without basal clamp connection; CYSTIDIA not seen; HYPHAE dimitic, 1) generative hyphae 2-3 microns wide, light yellow, thin-walled, without clamp connections, 2) skeletal hyphae 2-2.5 microns wide, brown, thick-walled, without septa; HYPHAL STRANDS up to 15(20) microns wide, (Breitenbach)