Summary:
Features include 1) a more or less spherical, often lobed fruitbody with a surface that is snow white soon discoloring to whitish to grayish vinaceous or pinkish buff or olive buff, bruising reddish vinaceous, 2) a spore mass with small chambers that is white becoming olive buff to dark olive, 3) a metallic-disagreeable odor when old, 4) growth under 2-needle and 3-needle pines and Douglas-fir, 5) a FeSO4 reaction on surface that is distinctly olive, KOH quickly pinkish to red, 6) narrowly oblong spores, and 7) a peridium with a poorly differentiated epicutis intergrading into a subcutis of broader hyphae, both layers or only the epicutis with ochraceous to ochraceous tawny pigment encrusted on the hyphal walls. "This is a distinctive species in that the peridium gives a red reaction in KOH but the sections revived in KOH show none of the vinaceous tints or vinaceous to vinaceous-brown debris in the layer which usually accompanies this character in other species" (Smith(30)). Var. evadens is abundant among false truffles in the Pacific Northwest (Trappe(13)).

Chemical Reactions:
FeSO4 on surface slowly distinctly olive (on dried specimens slowly dark olive), KOH quickly pinkish to red, (Smith(30)), FeSO4 on peridium slowly olive, negative on spore mass; KOH on peridium reddish brown, on young spore mass often pinkish white, (Miller)

Interior:
white when young, olive buff to dark olive when mature, (Smith(4)), "white becoming olive-buff to darker olivaceous; chambers small", (Smith(30)), soft, cake-like when young, then tough, cartilaginous when old, when dried hard in consistency but easy to section; white when young, then grayish yellow, "maturing centripetally with pale coloration proximal to the peridium", young or mature spore mass often bruising pale red to dull red, when dried spore mass pale yellow to light yellow; loculate [chambered], 4-5 per mm when young up to 2-3 per mm when mature, (Miller)

Odor:
when old often acid to somewhat metallic-disagreeable, (Smith(30)), not distinctive to acidic disagreeable when old, (Miller)

Microscopic:
spores 6-8 x 2-2.3 microns, "peridium with a poorly differentiated epicutis of appressed hyphae intergrading with a zone of broader, almost cellular, hyphae, at least the epicutis with ochraceous to ochraceous tawny pigment incrustations", (Smith(4)), spores 6-8 x 2-2.3 microns, narrowly oblong, smooth, inamyloid (pale yellowish singly and in groups in Melzer''s reagent), in KOH colorless singly but yellowish in groups; basal scar inconspicuous; basidia 4-spored, 6-spored, and 8-spored, 16-22(26) x 5-6 microns, subclavate, colorless, thin-walled, soon collapsing; paraphyses like basidioles or wider, 15-20 x 6-12 microns, colorless, thin-walled; subhymenium "cellular from inflated cells of the lower part of the hymenial elements", tramal plates composed of hyphae 2.5-6 microns wide, interwoven, refractive-gelatinous, and colorless in KOH; peridium basically 1-layered but a poorly differentiated epicutis of appressed hyphae 3-6 microns wide can be made out, this intergrading into a subcutis of hyphae 8-20 microns wide, "and often almost cellular in sections (from viewing cut ends), both layers or only the epicutis with ochraceous to ochraceous tawny pigment encrusted on the walls, or lower layer almost devoid of pigment", the hyphal walls thin but not gelatinous; all tissues inamyloid; clamp connections absent, (Smith(30)), spores (5.5)6.0-8.0 x 2.5-3.0(3.5) microns, narrowly oblong to oval, often curved in side view, in Melzer''s reagent pale yellow singly, olive yellow in mass, mostly with 2 lipid droplets, in KOH colorless to pale yellow singly, pale yellowish gray in mass, basal scar present but not prominent; basidia borne in a distinct hymenium, 4-spored, 6-spored, or 8-spored, 15-26 x 5-6 microns, narrowly clavate, thin-walled, soon collapsing, brachybasidioles 8-25 x 6-15 microns, nearly spherical, clavate or obovate, thin-walled to moderately thick-walled when young, thick-walled, mucilaginous when old, readily disarticulated in crush mounts; subhymenium poorly developed, composed of hyphae that are colorless, "thin-walled, cubical, elongated or branching cylindrical"; trama composed of hyphae that are 3-8 microns wide, loosely interwoven, colorless, cylindric to slightly swollen, refractive in KOH, thin-walled when young, highly gelatinous when old, oleiferous hyphae common in mediostratum, 4-13 microns wide, "hyaline refractive in KOH, yellow refractive in Melzer''s reagent", cylindric or irregularly swollen and contorted, branching; peridium 200-320 microns thick, peridial epicutis composed of hyphae 3-5 microns wide, tightly appressed, parallel, thin-walled, gelatinous, "heavily encrusted with dull yellow to orange yellow amorphous pigment in KOH, bright yellow orange in Melzer''s reagent", peridial subcutis "present but not well differentiated from epicutis", of hyphae 5-25 microns wide, cylindric, thin-walled, nongelatinous, "with abundant hyphal strands appearing in cross-section as nests of sphaerocysts", oleiferous hyphae abundant, 5-12 microns wide, "hyaline refractive in KOH, yellow refractive in Melzer''s reagent", cylindric or irregularly swollen and contorted, "branching, lightly encrusted with dull yellow pigment or free from encrusting material"; clamp connections absent, (Miller)

Notes:
Rhizopogon evadens var. evadens is found in WA, OR, northern CA, ID, and eastern North America, (Trappe(13)). Var. evadens collections were examined from ID, OR, NS, (Smith(30)). Var. evadens collections were examined from OR, ID, MS, NC, OH, TN, and VA, (Miller). R. evadens is common in ID and reported from BC, WY, NM, and NS, (Smith(4), perhaps including both varieties).