Summary:
Clade Deliciosi. Lactarius aurantiosordidus is distinguished from other Lactarius with orange milk "by the small size, dingy orange, green-stained cap, unchanging orange latex, and growth with Sitka spruce" (Siegel(2), discussing the Redwood Coast in California). |Lactarius aurantiosordidus was described from Redwood National Park in California. The name Lactarius deliciosus var. olivaceosordidus has been used for this species in California (Siegel(2)). Along with their original description of Lactarius aurantiosordidus, Nuytinck(1) examined collections identified as Lactarius deliciosus var. olivaceosordidus (including the holotype) from Washington, Oregon, and Del Norte and Humboldt Counties in California. They do not synonymize it with L. aurantiosordidus, commenting only that collections of L. aurantiosordidus do not group with any of the known species in their molecular analyses. They mention two collections from WA identified as Lactarius deliciosus var. olivaceosordidus, one of which groups with other collections identified as Lactarius ''deliciosus'' or one of its varieties while the other does not (they do not mention whether the latter is close to Lactarius aurantiosordidus). Their conclusion is that Lactarius deliciosus var. olivaceosordidus as currently identified in North America is polyphyletic.

Gills:
broadly attached to slightly decurrent, narrow, close to crowded, fragile; orange, ocher to orangish buff, "developing turquoise to greenish olive discolorations, especially when damaged or in age", (Siegel), "adnate to slightly decurrent, crowded when young, becoming close"; salmon to pinkish orange when young, dull greyish orange when old, (Nuytinck)

Stem:
2-6cm x 0.7-2cm, equal, widening slightly or narrowing slightly at base; orange to mottled orangish brown, "discoloring turquoise-green to olive green", (Siegel), 2.5-5cm x 0.6-1.2cm, mostly equal, occasionally narrowing downwards, "sometimes irregularly shaped", stem becoming hollow; colored as the cap, frequently paler at the top; "faintly tomentose or felted when young, remaining so at the base but felted aspect soon disappearing where handled", "scrobicules rare or absent", "basal tomentum whitish to buff", (Nuytinck)

Odor:
indistinct (Siegel), indistinctive (Nuytinck)

Taste:
mild or slowly slightly peppery (Siegel), mild to very slowly faintly peppery (Nuytinck)

Microscopic spores:
spores 8.5-10 x 6.5-7.5 microns, broadly elliptic to elliptic, "ornamented with isolated warts and ridges, forming a partial reticulum", (Siegel), spores 8.7-9.9 x (6.5)6.6-7.5 microns, broadly elliptic to elliptic, ornamentation up to 0.5 microns high, "of medium thick ridges and isolated warts, forming an incomplete reticulum", "plage mostly not amyloid"; basidia 40-55 x 8-11 microns, "subclavate to almost cylindrical, with a striking, dark coloured, granular content and abundant, pigmented oil-droplets", basidioles "with a similar content to the basidia, only very few hyaline basidioles present"; pleuromacrocystidia very scarce, 40-50 x 6-8 microns, "slightly emergent, subfusiform with a narrowing apex, hyaline, thin-walled", pseudocystidia very abundant, 2.5-5.5 microns wide, "sometimes slightly emergent, tortuous to cylindrical, sometimes branching, with a striking, deep ochre-brown colour", gill edge sterile without cheilomacrocystidia, marginal cells 20-35 x 7-10 microns, "subclavate, with a dark coloured granular content and oil-droplets"; cap cuticle a thin ixocutis, up to 100 microns thick, "composed of strongly interwoven hyphae" 1.5-5 microns wide; clamp connections absent, (Nuytinck)

Spore deposit:
creamy to pale yellow, (Siegel), pale yellow orange (Nuytinck)

Notes:
Besides its occurrence in CA where it was originally described, it has been reported from OR, (D. Miller, pers. comm. and collection in Debbie Viess images). According to D. Miller (pers. comm.), DNA from a collection on Vancouver Island in BC and from a collection in OR is a 100% match to the holotype.

EDIBILITY