Summary:
Pholiota adiposa is a member of the Pholiota aurivella group (yellow to orange viscid cap with large spot-like darker scales, scaly stem, and brown spore deposit): of the Pholiota aurivella group, 90% in PNW are P. limonella and most of the rest P. aurivella. P. adiposa is rare from North America but is distinguished by viscid or slimy scales on the stem and spores 5-6 x 3-4 microns, (Smith). To complicate matters, Pholiota aurivella (Batsch: Fr.) Kummer non sensu Batsch and Pholiota adiposa sensu Fr. are both given by Breitenbach(4) as synonyms of Pholiota cerifera (Karst.) Karst., and they give P. adiposa (Batsch: Fr.) Kummer sensu auct. non Fr. as a synonym of Pholiota jahnii Tjall. & Bas. Trudell(4) says that Pholiota adiposa is another name for Pholiota aurivella (Batsch: Fr.) P. Kummer and that some mycologists feel it is preferable. The online Species Fungorum, accessed April 11, 2016, lists Pholiota adiposa (Fr.) Kumm. separately but says that Pholiota adiposa sensu Holec (2001) is Pholiota aurivella (Batsch) P. Kumm. and Pholiota adiposa sensu auct. is Pholiota jahnii Tjall.-Beuk. & Bas.

Cap:
6-9(16)cm across, convex then flat; yellow to dark yellow; viscid or glutinous, with ferruginous brown, more or less concentric scales that dry down to resemble cherry-gum, (Smith), 3-17cm across, cap eventually flat, sometimes humped; covered with rust-colored scales on yellow background; the scales floccose-gelatinous, concentric and dropping off, viscid in wet weather, (Lincoff)

Flesh:
yellow, (Smith), yellowish, light brown at stem base, (Lincoff)

Gills:
adnate to sinuate, close, broad; at first yellow or straw yellow, becoming ferruginous, (Smith), adnate, broad; yellowish then rust-colored, (Lincoff)

Stem:
5-12cm x 0.6-1.5cm, base enlarged; yellow in upper part, becoming ferruginous brown downward; viscid or glutinous, with numerous, glutinous, superficial, squarrose or recurved scales up to the apical ring, (Smith), 6-16cm x 1-2.5cm, enlarged toward base; first whitish then yellow; covered below ring by pointed, rust-colored scales, gelatinous-viscous, (Lincoff)

Veil:
partial veil yellowish, subfloccose, forming an evanescent [fleeting] ring, (Smith), membranous veil forming ring, which is yellow then rust-colored, (Lincoff)

Odor:
none (Lincoff)

Taste:
slightly bitter (Lincoff)

Microscopic spores:
spores 5-6 x 3-4 microns, ovate to elliptic in face view, subelliptic to slightly bean-shaped in side view, smooth, with a minute germ pore, pale tawny to clay color in KOH, merely ochraceous in Melzer''s reagent, wall thin (to 0.25 microns); basidia 4-spored, 16-20 x 3.5-5 microns, narrowly clavate, colorless in KOH, weakly yellowish in Melzer''s reagent; pleurocystidia of two types 1) 25-40 x 5-10 microns, subfusoid, walls thin, smooth, and colorless, content coagulated and shrunken away from walls, wrinkled, dark brown in KOH and in Melzer''s reagent, 2) chrysocystidia 18-28(33) x 6-9(13) microns, fusoid to somewhat fusoid-ventricose, walls thin, smooth and colorless, inclusion small, colorless in KOH and Melzer''s reagent, usually well defined; clamp connections present, (Smith from specimen from England), spores 5-7 x 3-4 microns, elliptic, smooth, (Lincoff)

Spore deposit:
rust-brown (Lincoff)

Notes:
Smith(3) examined collections of Pholiota adiposa from BC, Slovakia, and the United Kingdom. Martin, K.J.(3) reported it from BC and CO. A collection from WA by Kit Scates are likely to have been diagnosed using the spore size concept in Scates(2). There is a collection from British Columbia by O. Ceska but it is not known whether spores were measured. Oregon State University has collections from Oregon, Idaho, and Missouri, but they were all collected from 1940 and the concept used is uncertain.

EDIBILITY

mediocre (in Europe), (Lincoff)