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

Summary:
Features include 1) a nearly spherical to irregular fruitbody with a surface that has an overlay of dark fibrils but is pallid becoming dark brown, 2) a pinkish layer (exposed by separation of the outer layer) that soon stains blue and finally umber, (the bruising reaction also described as pink to violet), 3) an olive spore mass, 4) an inky fuscous KOH reaction on the fresh surface of the fruitbody, 5) a slowly dark olive FeSO4 reaction on the fresh surface, 6) growth in duff under Douglas-fir and Sitka spruce, and 7) microscopic characters including relatively short spores, a peridium with flagellate hyphal ends, and a peridial subcutis that is a thick layer reddish in KOH on revived material. Molecular evidence has been presented to support the contention that R. parksii (the holotype) is a synonym (along with a R. hawkerae paratype and R. colossus var. colossus paratypes) of R. villosulus A.H. Sm. (Martin, M.P.(2)). On the other hand, other molecular evidence suggests that R. villosulus (a different collection), R. colossus (the holotype), R. hawkerae (the same paratype), and R. villescens (non-type) are close and could be a single species that shows variation, whereas two non-type collections of R. parksii were more distant, (Grubisha(2)). Rhizopogon parksii is abundant among false truffles in the Pacific Northwest (Trappe(13)).

Rhizopogon parksii, using the Smith & Zeller(1966) concept, is found in WA, OR, and CA and is the most abundant Rhizopogon in the Sitka spruce zone along the coast, (Smith(4)). R. parksii occurs from southwestern BC to northern CA and ID, (Trappe(13) who list also Rhizopogon villosulus, R. villescens, and R. hawkerae, but not R. colossus). R. parksii is known from hundreds of locations in BC, western WA, western OR, and northern CA, (Castellano(1)).

Outer Surface:
up to 1-4cm across, nearly spherical to irregular and lobed; when young white, "staining pink to violet where bruised", when old developing a covering of dark hyphae, when mature dark gray to dark olive with brown to brown-black areas overlying dingy white; felty, (Castellano), " 1-3cm, pallid with overlay of dark fibrils, becoming dull brown, unpolished to loosely appressed-fibrillose, the outer layer separating to expose the pinkish ground color (which soon stains blue and finally umber), as dried showing vinaceous-brown areas between the fuscous patches", (Smith(4)), 1-3cm across, spherical to oblong or irregular; "pallid with dark fibrils over it, becoming dull brown; unpolished to loosely appressed-fibrillose, the outer layer separating to expose a pinkish ground color, but this soon turning to blue and finally umber (blackish) on exposure to air, when handled staining bluish (dull indigo) and then blackish, when dried bluish fuscous with dingy vinaceous brown areas often showing between the fuscous patches", (Smith(30)), pallid to brown or pinkish, but stains dingy purple to bluish-black on surface when bruised or when old, (Arora), smudgy white when young, when mature gray to brown, when young staining slightly pink when cut or bruised, later sometimes staining gray or violet, (Trappe, M.(3))

Chemical Reactions:
KOH on fresh surface inky fuscous, FeSO4 slowly dark olive, (Smith(30))

Interior:
white when young, soon becoming gray to olive, when mature dark olive-gray to dark olive, (Castellano), chambers small, empty, firm but not bone-like in consistency; dull tan (pale wood-brown when dried), (Smith(30)), white when young, when mature gray to grayish olive, "sometimes with vinaceous to purple stained areas", (Trappe, M.(3))

Odor:
fungoid to pungent (Castellano), mild to slightly garlicky or of spicy sausage, (Trappe, M.(3))

Taste:
not distinctive (Castellano), mild to slightly garlicky or of spicy sausage, (Trappe, M.(3))

Microscopic:
spores 5-7 x 2.5-3 microns, elliptic to oval, smooth, colorless, thin-walled; basidia 14-16 x 4-6 microns; trama of interwoven hyphae with walls that become gelatinous-thickened when mature; subhymenium cellular; peridium "with an epicutis of brown, loosely interwoven hyphae with thin to somewhat thickened walls, flagellate hyphal ends often common, in water or Melzer''s reagent with scattered to abundant black granules than dissolve in KOH to form a green fluid", subcutis a relatively thick layer of interwoven, colorless, thin-walled hyphae, "the layer pink to red in KOH and often with red to orange amorphous debris", (Castellano), spores 5.5-6.5 x 2.3-3 microns, subelliptic, "subhymenium cellular, the cell walls gelatinous at maturity; peridium with flagellate hyphal ends; subcutis a thick layer reddish in KOH on revived material ", (Smith(4)), spores 5.5-7 x 2.3-3 microns, elliptic to ovoid, smooth, in Melzer''s reagent yellowish singly and in groups, in KOH colorless singly but pale snuff-brown in masses, with a false septum in Melzer''s and in KOH, basal scar very inconspicuous; basidia 14-16 x 4-6 microns, readily collapsing; paraphyses "with end cell 14-20 x 6-12 microns, ovate, elliptic or elongate, thin-walled at first, becoming thick-walled, amorphous central inclusion not coloring in KOH, in the thick-walled stage easily breaking at the septa", thick-walled paraphyses lacking in specimens in which gleba is still white; amyloid particles appear in the hymenium in some collections; tramal plates of colorless refractive gelatinous interwoven hyphae; subhymenium "cellular and the cells with refractive-gelatinous walls but most not developing thickenings"; peridium "duplex, outer layer a loosely interwoven weft of hyphae with dull cinnamon-brown walls, sparingly to frequently branched, walls thin to thickened and smooth, flagellate hyphae ends fairly numerous, some amorphous pigment greenish in KOH along the base of this layer", subcutis "a thick (about 100 microns) layer of interwoven hyphae strongly reddish as revived in KOH" and with numerous large laticiferous hyphae colorless in KOH and yellow in Melzer''s reagent (up to 20 microns wide), also in Melzer''s reagent "much blackish green to blackish violet debris present on the hyphae of this layer, in KOH the zone beneath this layer including the young locules dark green, the red pigment as seen in KOH is in intercellular pockets and masses of pigment aggregated along the hyphae"; clamp connections absent; all tissues inamyloid, but some hyphal fragments amyloid, (Smith(30)), spores 4.5-6.5 x 2.3-3 microns (Trappe, M.(3))