Summary:
Features include 1) a dull cinnamon to orange-brown or yellowish cap that is viscid, appressed-fibrillose and somewhat streaked, sometimes with hanging veil remnants on margin, 2) cap flesh that is yellow staining pinkish, the stem flesh yellow staining blue-green in the base and vinaceous brown elsewhere, 3) large angular to irregular pores that are often radially arranged, the pores yellow to ocher bruising dingy vinaceous brown, 4) stem that is yellow above the whitish fibrillose band-like annulus and dull ocher-brown appressed-fibrillose below it (staining brown when bruised or sometimes blue near base), the stem lacking glandular dots but often weakly reticulate at top, and 5) growth under conifers, particularly Douglas-fir.

Odor:
not distinctive (Bessette), mild or slightly acidulous (Smith(34)), none or slightly sour, (Phillips)

Taste:
not distinctive (Bessette), mild or slightly acidulous (Smith(34)), none or slightly sour, (Phillips)

Microscopic:
spores 8-11 x 3-5 microns, elliptic, smooth, colorless to ochraceous, (Bessette), spores 8-11 x 3-5 microns, elliptic, smooth, pale orange-buff to cinnamon-buff in Melzer''s reagent, colorless to ochraceous in KOH; basidia 4-spored, 20-30 x 5-8 microns, clavate, yellowish in KOH and Melzer''s reagent; pleurocystidia of 2 types: 1) cylindric to clavate with brown pigment around base of cluster, 35-70 x 5-8 microns, content brown to colorless in KOH, 2) fusoid-ventricose and isolated to scattered, 22-28 x 5-8 microns, with refractive granules, cheilocystidia in clusters and 60-100 x 5-9 microns, cylindric to clavate or narrowly fusoid-ventricose, colorless to yellow-brown; cap epicutis a collapsed trichodermium with elements 8-17 microns wide, and a basal layer with elements mostly unbranched and 3-7 microns wide and colorless to pale ochraceous in KOH, the layer gelatinous and up to 400 microns thick; tube trama with numerous large contorted laticifers present, cap flesh with occasional laticifers; caulocystidia similar to cheilocystidia (in clusters and with pigment at base of cluster) occurring only at the annulus level; clamp connections absent, (Smith(34))

Spore Deposit:
cinnamon-brown (Bessette), dingy cinnamon (Smith(34))

Notes:
Suillus caerulescens is found from the Rocky Mountains to the Pacific Northwest, (Bessette), only in Pacific Northwest and CA, (Arora), in WA, OR, and CA, (Smith(34)), in ID (Smith(36)), in BC (in Redhead), and in MT (L. Evans, pers. comm.).

EDIBILITY

edible, with a lemony flavor, (Bessette)

Synonyms and Alternate Names:
Oligoporus caesius (Schrad.: Fr.) Gilb. & Ryvarden
Polyporus caesius Schrad.: Fr.