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

Summary:
Features include 1) a yellowish brown to gray-brown or olive-brown viscid cap, 2) white unchanging milk that slowly stains flesh yellow and gills brownish, 3) close, whitish then pinkish brown gills, 4) a slimy stem that is off-white to pale brown or brownish gray, 5) a mild then peppery taste, 6) growth in the spruce-fir zone of the Rocky Mountains often in tufts, 7) a pale buff spore deposit, and 8) elliptic spores with amyloid ridges and prominences up to 0.5 microns high.

Material was cited for WA, OR, ID, CA, CO, UT, and WY, (Hesler(4)). It has been reported from western AB (Kernaghan). There are collections from BC at the Pacific Forestry Centre and the University of British Columbia, and collections from AK at the University of Washington.

Cap:
4-10cm across, "convex with an inrolled margin, becoming shallowly depressed with an upturned margin"; tawny brown to gray-brown or olive-brown; smooth, viscid, (Phillips), 4.5-10(15)cm across, convex with inrolled margin, becoming shallowly depressed with arched margin; azonate, 'evenly "drab" or varying toward "buffy brown" (gray brown to olive-brown)'; viscid, bald, (Hesler), yellowish brown to brown (Methven)

Flesh:
thick, brittle; white, unchanging when first cut, but turning yellow after several hours, (Phillips), thick, brittle; white, "at first unchanging when cut but after several hours or overnight changing to yellow," (Hesler), MILK scanty; white, "unchanging but slowly staining flesh yellow and gills brownish", (Phillips), scanty; "white, not changing color, staining the flesh yellowish slowly and the gills brownish", (Hesler), copious, white to pale yellow, unchanging, slowly staining the flesh pale yellow on exposure, staining gills light brown where cut, (Methven)

Gills:
"adnate becoming decurrent, close, narrow becoming broad", 2 or 3 tiers; whitish then pinkish brown, (Phillips), adnate becoming short-decurrent, close, narrow becoming broad, 2-3 tiers of subgills; whitish but finally pale pinkish buff to pinkish buff, some finally gradually sordid brown where bruised, (Hesler), pale yellow to grayish yellow (Methven)

Stem:
3-7cm x 1-3cm, "hollow; off-white to pale brown or brownish gray"; slimy and viscid when fresh, shiny when dry, (Phillips), 3-7cm x 1-3cm, hollow; pallid to pale brownish or brownish gray; slimy-viscid fresh, shining when dry, (Hesler), brownish orange to yellowish brown (Methven)

Odor:
pleasant (Phillips)

Taste:
mild then peppery (Phillips), burning-peppery (Hesler)

Microscopic spores:
spores 9.5-11 x 7.5-9 microns, broadly elliptic, amyloid, ornamented with prominences 0.2-0.5 microns high, "forming a partial or incomplete reticulum", (Phillips), spores (8)9-12 x 7-9 microns, broadly elliptic, "ornamentation a broken to partial reticulum with angular variable-sized meshes, the lines broad to rather fine and in many spores the reticulum not complete", prominences 0.2-0.5 microns high; basidia 4-spored, 45-60 x 9-12 microns; pleurocystidia: macrocystidia abundant, 60-105 x 9-12 microns, "subcylindric and blunt, becoming fusoid and pointed", originating in subhymenium or gill trama, "many of them dull pale ochraceous revived in KOH", content not spangled revived in KOH, cheilocystidia abundant, 45-60 x 9-16 microns, "clavate to mucronate or similar to macrocystidia"; cap cuticle an ixotrichoderm of elements about 60 x 2-3 microns, "these originating in a layer of compact hyphae", "hyphal incrustations occasionally present in subcuticular area", (Hesler), cap cuticle "an ixotrichodermium arising from an interwoven layer of filamentous hyphae, dextrinoid debris and incrustations present", (Methven)

Spore deposit:
pale buff (Phillips, Hesler), pale yellow (Methven)