Summary:
Sarcomyxa serotina is recognized by 1) its viscid, greenish to yellowish or violet-tinted, kidney-shaped or fan-shaped cap up to 10cm or 15cm in diameter, 2) pale yellow to ocher or pale orange gills, 3) a short, stubby, lateral stem, and 4) growth on wood. |It is fairly common in the Pacific Northwest in fall and winter, (Arora). |The online Species Fungorum, accessed May 16, 2020 listed the current name as Hohenbuehelia serotina, while MycoBank, accessed the same day, listed the current name as Panellus serotinus. Sarcomyxa serotina is commonly used as the current name.

Gills:
"adnate to decurrent, close"; "pale orange to ochraceous to pale yellow", often fading when old, (Arora), subdecurrent and +/- set off from stem, 50-110 reaching stem, broad at cap margin, increasingly narrow toward the stem, forking, 5-16 subgills between neighboring pairs of gills; cream then cream to ocher; "edges smooth and somewhat floccose", (Breitenbach), crowded, narrow; ocher-yellow to slightly violet on edges, (Phillips)

Stem:
"absent or if present, laterally attached, short and stubby", 0.5-2.5cm long; yellow to brownish or cap-colored; hairy or velvety, (Arora), 0.8-1.5(2)cm x 0.8-2cm, short, conic, solid; "punctate from dark scales on an ocherish to saffron-yellow background, sometimes almost strigose toward the base", (Breitenbach), "rust to orange" (Schalkwijk-Barendsen), white (McKnight), "usually yellow, sometimes flecked with brown or dull green", (Ammirati)

Veil:
absent (Arora)

Odor:
not distinctive (Bessette), faint, pleasantly mushroomy (Breitenbach)

Taste:
not distinctive or bitter (Bessette), "mild, somewhat bitter after being chewed for a rather long time", (Breitenbach)

Microscopic spores:
spores 4-6 x 1-2 microns, sausage-shaped [cylindric to slightly curved], smooth, typically amyloid at least in dried specimens, (Arora), spores 3.7-6.5 x 1-1.5 microns, cylindric, allantoid, smooth, with droplets; basidia 4-spored, 13-20 x 2.5-3 microns, cylindric, with basal clamp connection; pleurocystidia sparse, like cheilocystidia, cheilocystidia numerous, 30-60 x 9-15 microns, clavate to fusiform, "sometimes with yellowish contents or covered in places with an amorphous, refractive substance", (Breitenbach)

Spore deposit:
yellowish (Arora), white (Breitenbach)

Notes:
Sarcomyxa serotina is found specifically in BC (in Redhead(5)). It was reported from OR by Kauffman(5) and by Zeller(2). The University of British Columbia has collections from BC and the University of Washington has collections from WA, OR, ID, CA, AK, and NY. It occurs throughout much of North America (Phillips) and also occurs in Europe (Breitenbach).

EDIBILITY

yes, mediocre and sometimes bitter as it ages, (Arora), no (Phillips), edible but rather tough, must be cooked a long time over low heat, (Bessette), stomach upset recorded (Brown)

Synonyms and Alternate Names:
Panellus serotinus (Pers.) Kuehner