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

Summary:
Features include 1) a spherical to irregular fruitbody with the surface pale rose to peach pink to salmon pink or pinkish ochraceous or whitish, typically with scattered salmon buff to dingy vinaceous buff rhizomorphs over the surface, 2) a minutely chambered spore mass that is pallid to olive and when old dark yellow brown, 3) chemical reactions to KOH on the surface, 4) smooth, oblong spores from 6-spored and 8-spored basidia, and 5) a 1-layered peridium of appressed interwoven hyphae, with the walls ochraceous in KOH and with some amorphous pigment present in the epicuticular region. This is a collective species with several varieties based on the color of injured areas and the reactions of the peridium to KOH: a) var. subsalmonius has no bruising color change on the surface and KOH gives a pinkish lilac reaction on the parts of the fresh surface tinged pink or salmon (the great majority of collections in ID fitting this variety), b) var. griseolilacinus does not stain pinkish when injured, but KOH gives a pale lilac-gray reaction on the surface, c) var. roseitinctus does not stain pinkish with handling and has no KOH reaction on the fresh peridium, d) var. similis stains pinkish (vinaceous) with handling, it has pockets of inflated cells in the peridium, and many spores are dextrinoid, and e) var. persicinus stains pinkish (vinaceous) from handling, but lacks pockets of inflated cells in the peridium. The Smith(4) description used below is for R. subsalmonius, and the Smith(30) description used below is for R. salmonius var. subsalmonius. Rhizopogon subsalmonius is common among false truffles in the Pacific Northwest (Trappe(13)).

Rhizopogon subsalmonius is found from WA to northern California, ID and AZ, (Trappe(13)). It is known from BC, WA, OR, ID, and WY according to Smith(4), but the varieties were described from ID in Smith(30).

Outer Surface:
1-6cm across, "pale to bright peach pink to salmon pink or white, often fading to whitish, at times pinkish ochraceous"; appressed-fibrillose, dry; typically with scattered salmon buff to dingy vinaceous buff rhizomorphs over the surface, (Smith(4)), 1-6cm across, spherical to nearly spherical or irregular, often angular from mutual pressure; pale rose to peach-red to pale salmon color when young, but soon fading to salmon-buff to pale buff or whitish, when old often whitish to olivaceous where exposed and pinkish on underground parts; appressed-fibrillose, dry, unpolished; "typically with scattered salmon-buff rhizomorphs over the surface", "the rhizomorphs remaining with some pinkish tones even if the surface is whitish to pale buff or olivaceous"; peridium not changing color when cut or bruised or staining very lightly, (Smith(30)), pale peach pink to light salmon when young, "later yellowish salmon to brownish salmon", "with salmon-colored rhizomorphs appressed here and there on the peridium, thin and easily rubbed off", (Trappe, M.(3))

Stem:
columella none (Smith(30))

Chemical Reactions:
KOH staining the pink fresh surface pinkish lilac but usually no reaction on white or buff areas (for var. subsalmonius, see above for other varieties); fresh surface in FeSO4 slowly pale olivaceous but dried surface soon olive-black, (Smith(30))

Interior:
firm-cartilaginous when fresh, "sectioning easily when dry"; "pallid to olivaceous to dark olive", dark yellow brown when old; chambers minute, empty, (Smith(30)), dark olive to dark yellow brown at maturity; "sectioning easily when dry", (Smith(4)), white when young, "becoming olive green and finally dark yellowish brown", (Trappe, M.(3))

Odor:
mild (Trappe, M.(3))

Taste:
mild (Trappe, M.(3))

Microscopic:
spores (5.5)6-8 x 2-2.5 microns; "peridium a thin layer of appressed interwoven hyphae, walls of hyphae ochraceous in KOH", (Smith(4)), spores (5.5)6-8 x 2-2.5 microns, oblong, smooth, in Melzer''s reagent yellowish singly or in groups more yellowish, in KOH colorless singly but pinkish buff in masses along the hymenium, basal scar indistinct; basidia 6-spored and 8-spored, 6-7 microns wide, thin-walled, readily collapsing; paraphyses 16-20 x 8-12 microns or more wide, "thin-walled, or rarely developing wall thickenings", colorless in KOH; subhymenium cellular, 2-3 cells deep; tramal plates composed of hyphae 2-6 microns wide that are colorless, refractive-gelatinous, subparallel in a central strand, walls thin to slightly thickened; peridium "thin, single-layered, of appressed interwoven hyphae, the cells at first 2-6 microns wide but at maturity 10-20 microns wide in single cells, with some amorphous pigment present in the epicuticular region and the walls ochraceous in KOH"; all tissues inamyloid; clamp connections absent, (Smith(30))