Summary:
Also listed in Polypores category. Features include 1) resupinate growth (often partly reflexed to form caps) on wood, more often hardwood, 2) caps when present shelf-like, projecting 1-5cm, often shingled, sometimes fused into formless clusters, soft-cartilaginous (horny when dry), the upper surface whitish to yellowish or pinkish, azonate or somewhat zonate, and tomentose to hairy, 3) a spore-bearing surface that is waxy, soft, gelatinous, translucent, pale orange-yellow to deep orange-red, and merulioid, with folds narrow, radial, branching to less prominent side ridges, sometimes forming nearly rectangular pore-like pits, 1 or 2 per millimeter, 4) spores that are cylindric to allantoid, smooth, inamyloid, and colorless, 5) cystidioles that are cylindric, projecting, and often encrusted, and 6) a monomitic hyphal system, the hyphae with clamp connections. It is common from the southern US to the tree line in Canada (Ginns(12)).

Microscopic:
SPORES 3.5-4.5 x 1-1.5(2) microns, cylindric, in side view allantoid to reniform [kidney-shaped], smooth, IKI-, colorless, very pale blue in lactic-blue, thin-walled, some containing 2 droplets; BASIDIA 17-28 x 3-5 microns, of the chiastobasidium type, narrowly clavate; SUBHYMENIUM and hymenium of some specimens with granular deposits throughout; HYPHAE monomitic, context of 2 layers, 1) the abhymenial layer with hyphae 2-5.5 microns wide, randomly oriented, rather loosely woven, colorless, rather thin-walled to thick-walled, with clamp connections, lacking granular deposits, with interspersed waxy strands, 2) abruptly (closer to hymenium) the hyphae become "closely packed, parallel, horizontally oriented", this hyphal layer extending to the hymenium; "at the base of the folds the hyphae are randomly oriented, serpentine, more widely spaced, becoming flexuous and loosely woven in the folds", these hyphae having walls rather thin and with colorless, apparently gelatinous droplets up to 2 microns in diameter, scattered over their exterior, (Ginns(12)), SPORES 4-4.5 x 1-1.5 microns, allantoid, smooth, thin-walled, often with 2 droplets; BASIDIA 4-spored, 18-25 x 4-4.5 microns, narrowly clavate, in a very dense palisade, with a basal clamp connection (new basidia born from the clamp connection); CYSTIDIA not present, but often there are thin-walled hyphae in the hymenium, projecting 20-30 microns, often covered by pieces of excreted resinous matter; HYPHAE monomitic, with clamp connections; CONTEXT of 2 layers: 1) the abhymenial layer white and cottony in section, with distinct hyphae 4-5 microns wide, much branched in all directions, with thickened walls, "forming a net-like tissue, penetrated by strands of parallel hyphae", and 2) layer closer to the hymenium with hyphae 2-3(4) microns wide, thin-walled, irregularly intertwined into a ceraceous context (forming a layer of parallel hyphae instead in the cap trama); SUBHYMENIUM thickening, formed by hyphae 2-3 microns wide, thin-walled, richly branched, in an almost pseudoparenchymatic tissue, (Eriksson), SPORES 3.5-4 x 1(1.5) microns, cylindric, allantoid, smooth, inamyloid, colorless, some with droplets; BASIDIA 4-spored, 20-25 x 3-4 microns, narrowly clavate, with basal clamp connection; CYSTIDIOLES 30-45 x 3-4 microns, cylindric, some encrusted; HYPHAE monomitic, 2-4 microns wide, with clamp connections; HAIRS of upper surface 2-3.5 microns wide, colorless, with clamp connections, (Breitenbach), spore print white (Lincoff(2))

Notes:
Phlebia tremellosa has been found in BC, WA, OR, ID, AB, MB, NB, NS, ON, PQ, SK, AR, CA, CT, FL, GA, IA, IN, LA, MA, MD, MI, MN, MO, MT, NC, NY, OH, TN, VA, WI, and WV, (Ginns(5)). Besides the United States and Canada, it is widespread in Europe, and also found in Brazil, Uruguay, Morocco, China (including Tibet), India, Japan, Siberia in Russia, and Pakistan, (Ginns(12)). It occurs in Scandinavia (Eriksson) and Switzerland (Breitenbach).

Synonyms and Alternate Names:
Merulius tremellosus Schrad.
Morganella subincarnata (Peck) Kreisel & Dring
Poria chromatica Overh.
Poria crustulina Bres.