Summary:
Lactarius repraesentaneus is easily identified by 1) a yellowish cap with hairy margin, and 2) purple-staining milk. Other features include 3) a cap surface that is viscid when moist, and zoned to faintly zoned, developing rusty and purplish stains, 4) adnate to decurrent, close to crowded gills that are cream to pale ochraceous or pale orange before staining lilac to purplish, 5) a scrobiculate stem that is whitish to yellowish, lavender-stained to purplish-stained; 6) a mild to slightly bitter or slightly peppery taste, 7) growth under conifers especially spruce, 8) a whitish to yellowish spore deposit, and 9) microscopic characters including elliptic spores with amyloid ornamentation in the form of a broken reticulum. Hesler(4) point out that Britzelmayr gave the spore deposit as white and the taste as non-acrid [not peppery].

Cap:
(4)6-20cm across, "broadly convex with central depression and inrolled margin", becoming broadly depressed or vase-shaped when old; pale yellow to golden yellow to orange-buff, "often developing rusty and sometimes purple stains", sometimes zoned concentrically; viscid when moist, "smooth at center but coarsely hairy (fibrillose) toward the margin, which is bearded with woolly yellowish hairs when young", (Arora), 5-15cm across, convex to flat, disc depressed, margin incurved to decurved [downcurved]; "azonate or obscurely zonate, yellow to yellowish orange"; subviscid to viscid; coarsely fibrillose, margin coarsely bearded, (Methven), (4)6-15(20)cm across, convex-depressed to flat-depressed but usually the margin arched, when old broadly funnel-shaped; "pale to rich yellow or orange-yellow, developing clay color to rusty tints over central area, staining purplish where bruised", the fibrils at first pallid becoming yellowish and finally often +/- clay color, usually azonate but at times faintly zoned; "with varying degrees of viscidity depending on the weather, with an overlay of fibrils more coarse and numerous toward margin", disc +/- bald at times, (Hesler)

Flesh:
thick, brittle; "white, staining dull lilac or purplish slowly where cut or bruised", (Arora), 1-1.5cm thick at disc; "white, quickly staining lilac to violet on exposure", (Methven), firm, brittle; whitish, quickly stained dull lilac to purple, (Hesler), MILK "copious, white or creamy, drying or slowly staining wounded tissue dull purple or lilac", (Arora), white to pale yellow, unchanging, staining the flesh lilac to violet on exposure and the gills lilac to violet when cut, (Methven), copious, "often becoming whey-like to watery, rather viscous at first"; white to cream, "in contact with flesh changing to violaceous or lilac", (Hesler)

Gills:
adnate to decurrent, close; buff to dull ocher or orange-spotted, "with lilac or purplish stains where bruised", (Arora), "adnate to subdecurrent, close to crowded, narrow to broad", forking near stem; cream to pale ochraceous, not marginate, staining lilac to violet when cut, (Methven), "close to crowded, narrow to moderately broad", broad when old, some forking at stem; cream to pale ochraceous, "finally at times with a pale orange cast, soon spotted lavender to purplish where injured", (Hesler)

Stem:
4-12cm x 1-3(4.5)cm, equal or thicker in lower part, hard, hollow or stuffed; whitish or more often colored like cap, sometimes lilac-stained; usually prominently scrobiculate, (Arora), 5-10cm x 1-3cm, equal or club-shaped, round in cross-section, hollow; white to yellow; subviscid to viscid, bald, scrobiculate, (Methven), 5-12cm x 1-3(4.5)cm, equal or club-shaped, soon hollow, cortex hard; whitish to more or less cap-colored, staining lavender to purplish where injured; viscid at first, scrobiculate, at times lacking scrobiculi (and then dry), (Hesler)

Veil:
[none]

Odor:
not distinctive (Methven), not distinctive or faintly fragrant, (Hesler), "rather sweet, thyme or resin-like" (Buczacki)

Taste:
slowly bitter or peppery (Arora), not distinctive to slightly peppery (Methven), at times finally bitterish to slightly pepper or both, (Hesler), mild then bitter (Buczacki)

Microscopic spores:
spores 8-12 x 6.5-9 microns, elliptic, with amyloid warts and ridges, (Arora), spores 8.5-11.5 x 6.5-8.5 microns, broadly elliptic to elliptic, amyloid ornamentation a broken reticulum 0.5-1.0 microns high; basidia 50-70 x 10-14 microns; pleurocystidia: macrocystidia 60-120 x 9-15 microns, fusoid to fusoid-ventricose, with or without one or more subapical constrictions, cheilocystidia 45-60 x 6-10 microns, fusoid to fusoid-ventricose; cap cuticle an ixocutis; stem cuticle "a simple cutis, a distinct ixotrichodermium over the scrobiculi", (Methven), spores (8)9-11(12) x 6.5-8(9) microns, broadly elliptic to elliptic, colorless in Melzer''s reagent "or some with diffusely distributed amylaceous material over the surface or around the edge; ornamentation in the form of warts and ridges and sparsely branched bands not united into any sort of reticulum", prominences 0.4-0.8 microns high; basidia 4-spored, 60-70 x 10-14 microns, clavate; pleurocystidia: macrocystidia 70-120 x 9-15 microns, "fusoid to fusoid-ventricose with a long tapered neck ending in a sharp point, less frequently with a small apical capitellum or one or more subapical constrictions"; content +/- granular as revived; pseudocystidia apparently absent to rare; cheilocystidia scattered, "similar to macrocystidia but usually smaller"; cap cuticle "an ixocutis but poorly delimited in places", of narrow (4-6 microns wide) hyphae loosely aggregated into fascicles and +/- embedded in slime, "lacking incrustations and dextrinoid debris", (Hesler)

Spore deposit:
whitish to yellowish (Arora), pale yellow in mass, (Methven), yellowish: Crawshay B-C, (Hesler)

Notes:
Material was cited from ID, NS, ON, AK, AZ, CA, CO, ME, MI, NJ, NM, VT, and Sweden, (Hesler(4)). It was reported from BC by Bandoni(1) and collections from BC are present at the University of British Columbia. There are collections from OR, AK, CO, and MI at the University of Washington. The species also occurs in WA (A. and O. Ceska on Mushroom Observer; PSMS show 2009).

EDIBILITY

not recommended, may be poisonous, (Arora)

Synonyms and Alternate Names:
Lactarius representaneus Britzelm. sensu Neuhoff