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

Summary:
Gomphidius oregonensis is identified as a Gomphidius by the viscid-slimy cap, white flesh except in base of stem where it is yellow, soft decurrent gills, and smoky-black spores. It is identified as Gomphidius oregonensis by subtle features including the shortest spores of the genus, and the tendency to grow in cespitose clusters. It is common in the Pacific Northwest. Gomphidius spp. are thought to be parasitic on the mycelia of boletes and in the Redwood Coast of California, Gomphidius oregonensis appears associated with Suillus caerulescens in Douglas-fir habitat, (Siegel).

Collections were examined from WA, OR, ID, CA, and MT, (Miller). There are collections from BC at the University of British Columbia and the Pacific Forestry Centre.

Cap:
2-15(18)cm across, at first peg-like then broadly convex to flat or depressed; whitish to salmon buff to ochraceous salmon to dull pinkish when young, becoming dingier (brownish to purplish gray or vinaceous gray to dark reddish brown) when old, often spotted or stained smoky gray to black; viscid or slimy when moist, smooth, (Arora), 2-15cm across, broadly convex, "ochraceous-salmon" to light salmon buff when young, when mature dark reddish brown to "wood brown" at center, margin light vinaceous cinnamon, "avellaneous" to light cinnamon-buff becoming salmon pink; glutinous, (Miller)

Flesh:
rather soft; white or grayish (or tinged cap color under cap surface), but brilliant yellow in lower part of stem or at base, (Arora), thick, soft and spongy, tapering abruptly at margin; white except near surface where it is colored like the cap, in stem whitish becoming deep yellow over lower one third to one half, (Miller)

Gills:
"decurrent, soft and rather waxy, close to fairly well-spaced"; "white or pallid, then gray and finally blackish" from spores, (Arora), decurrent, subdistant to close, equal, some forked; white or pallid, becoming clouded smoky gray when old, (Miller)

Stem:
5-15cm x 1-5cm, equal or narrowing in lower part (or occasionally swollen), "solid, rather firm or even tough"; "dry and white above the veil, whitish or dingy below and viscid when wet, sometimes with darker streaks", lower part bright yellow, (Arora), 6-12cm x 1-5cm, equal, somewhat enlarged or narrowing at the base, solid, often partly buried; white on the upper one third above the ring zone, "glutinous below and yellow to deep yellow at the base, gluten blackening in some collections", (Miller)

Veil:
"whitish and fibrillose beneath a layer of slime, disappearing or forming a slight hairy-slimy superior ring" on stem, subsequently blackened by falling spores, (Arora), glutinous, colorless with a fibrillose one beneath, (Miller)

Odor:
not distinctive (Miller)

Taste:
not distinctive (Miller)

Microscopic spores:
spores 10-14(16) x 4.5-8 microns, spindle-shaped to narrowly elliptic, smooth, (Arora), spores 10.5-13(16) x 4.5-8.0 microns, elliptic in face view, subfusiform [somewhat spindle-shaped] in side view, smooth, gray-brown in KOH, light ochraceous-tawny in Melzer''s reagent; basidia 4-spored, 31.0-42.5 x 6-9 microns, clavate, colorless to light yellow in KOH, colorless or sometimes yellowish toward the top in crushed mounts in Melzer''s reagent; pleurocystidia and cheilocystidia 80-120 x 8-13 microns, clavate to cylindric, thin-walled, colorless in KOH, colorless in Melzer''s but some becoming yellow in crushed mounts; caulocystidia in small to large fascicles at top of stem, 75-146 x 12-28 microns, clavate, cylindric to occasionally fusiform, thin-walled, colorless to light yellow in KOH, yellow in Melzer''s reagent, incrustations none to heavy; clamp connections not found, (Miller)

Spore deposit:
smoky gray to black (Arora)