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

Lactarius olivaceoumbrinus Hesler
toadskin milk-cap

Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.

Introduction to the Macrofungi

© Kit Scates-Barnhart  Email the photographer   (Photo ID #19002)

E-Flora BC Static Map
Distribution of Lactarius olivaceoumbrinus
Click here to view the full interactive map and legend
Details about map content are available here
Click on the map dots to view record details.

Species Information

this species and close relatives recognized by overall dingy greenish to murky olive-brown color and copious white peppery milk; Hesler(4) cited collections from WA, OR, ID, and Methven(2) gives for CA, Miller(14) for AK, collections from BC at Pacific Forestry Centre and University of British Columbia, CHEMICAL REACTIONS cap surface staining magenta in KOH or ammonia, (Arora)
3-12cm across, convex with inrolled margin becoming flat or shallowly depressed; "typically a mixture of dark olive, sordid olive-brown, and olive-buff, often spotted or zonate concentrically", but zones fading when old; viscid when moist, (Arora), (2)4-10(12)cm across, convex with inrolled margin, expanding to flat or shallowly depressed; '"dark olive" on disc and deep olive toward the "dark olive-buff" margin, at times with green and "Isabella color" alternating zones, in age fading and nearly azonate, drying dark fuscous olive'; viscid, bald except pubescent margin, (Hesler), 8-15cm across, convex to flat, disc depressed, margin inrolled to incurved; olive brown to brown, zoned to obscurely zoned; fibrillose to fibrillose-scaly, subviscid to viscid, often water-spotted, margin pubescent to short-tomentose, (Methven)
thick, brittle; dingy olive, (Arora), thick, firm; pallid olivaceous, in stem changing to dingy gray, (Hesler), up to 1cm thick at disc, pale tan, unstaining on exposure, (Methven), MILK copious; white, turning greenish gray (sometimes very slowly), (Arora), copious; white, rapidly or slowly changing to greenish gray, (Hesler), white, unchanging, staining the gills olive brown where cut, (Methven)
adnate to decurrent, crowded; "pallid becoming spotted or colored greenish or olive-gray", (Arora), decurrent, crowded, narrow, many forking near stem; "pallid at first, becoming greenish then spotted dingy olive-gray", finally olive-gray overall; edges even, (Hesler), "subdecurrent, close to crowded, broad", forking near stem; pale orange, staining olive-brown where cut, finally brown overall; not marginate, (Methven)
4-8cm x 1-3cm, solid becoming hollow when old, rigid; more or less cap-colored; viscid when wet, then dry; usually scrobiculate, (Arora), (1.5)4-8(10)cm x (0.8)1-1.5cm, widening downward, occasionally narrowed in lower part, solid but hollow when old; more or less cap-colored; viscid, soon dry, bald, scrobiculate, (Hesler), 4-7cm x 0.8-1.5cm, round in cross-section, hollow, equal or narrowed toward base; olive-brown to brown; bald, "moist to subviscid, fibrillose-streaked", scrobiculate (scrobiculae darker), (Methven)
not distinctive (Methven)
very peppery (Arora), mild intensely peppery, "leaving a burning sensation afterward", (Hesler), slowly peppery (Methven)
Microscopic spores:
spores 7-10 x 6-9 microns, elliptic to nearly round, amyloid warts and ridges, (Arora), spores 7-9(10) x 6-8(9) microns, elliptic to nearly round, "broken to partial reticulum with bands frequently with free-ending branches, some isolated particles and warts present", prominences 0.4-1(1.5) microns high; basidia 4-spored, 45-57 x 8-11 microns; pleurocystidia: macrocystidia 45-75 x 5-10 microns, "fusoid, acute to acuminate, often with somewhat granular content, more numerous near the gill edges", "pseudocystidia scattered, content refractive, filamentous, embedded in the hymenium and inconspicuous", cheilocystidia 37-60 x 4.5-7 microns, "fusoid-acuminate, some with one or more subapical constrictions", (Hesler), spores 7-9(9.5) x 6-8 microns, broadly elliptic to elliptic, amyloid ornamentation a broken to partial reticulum 0.5-1.5 microns high; basidia 40-55 x 7-10.5 microns; macrocystidia 40-70(90) x 4.5-7.5 microns, fusoid to acuminate, often with one or more subapical constrictions, cheilocystidia 35-55 x 4.5-7.5 microns, fusoid to acuminate with one or more subapical constrictions; cap cuticle "an ixocutis, producing a diffuse magenta pigment in KOH"; stem cuticle "an ixocutis, producing a diffuse magenta pigment in KOH", (Methven)
Spore deposit:
pale buff (Arora), "light buff" (Hesler), white to pale yellow (Methven)

Habitat / Range

single or scattered or in small groups under conifers, late summer and fall, (Arora), single to widely gregarious on soil under conifers, (Hesler), single to scattered in duff, in coastal conifer-hardwood forests, associated with Picea sitchensis (Sitka Spruce), (Methven for California)

Taxonomic and Nomenclatural Links

Additional Range and Status Information Links


unknown (Arora)

Additional Photo Sources

Related Databases

Species References

Hesler(4) (colors in double quotation marks from Ridgway(1)), Arora(1), Trudell(4)*, Miller(14)*, Ammirati(5), Methven(2)

References for the fungi

General References