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

Summary:
Features include 1) a variously shaped fruitbody with a pale yellow to ochraceous or reddish brown surface, often mottled with red or reddish brown, sometimes reddening or turning fulvous with bruising, usually with conspicuous brown to reddish brown rhizomorphs that are intergrown with the surface, 2) a peridium that tends to slough off in patches, 3) a chambered spore mass that is whitish becoming olive to olive brown, 4) chemical characters, and 5) microscopic characters including smooth, narrowly oblong spores, 6-spored and 8-spored basidia, and a peridium with hyphal incrustations and interhyphal debris that both become magenta in KOH. It is abundant among false truffles in the Pacific Northwest (Trappe(13)). It is common in the Pacific Northwest (Smith(4)).

It is found from WA to southern CA, ID and CO, (Trappe(13)). It is found in BC, WA, OR, ID, NM, and WY, (Smith(4)). It has also been found in AZ (States(2)) and Mexico (in States(2)).

Outer Surface:
2-8cm across, golden yellow to tawny or ochraceous when young, overlaid with brown rhizomorphs, russet when old, sometimes staining fulvous with injury, when dried "and in contact with naphthalene (in herbarium) vinaceous red to vinaceous brown", (Smith(4)), 2-8cm across, spherical, nearly spherical, ellipsoid, lobed, flattened, or irregular; pale lemon-yellow to yellow-ocher to golden yellow to tawny yellowish or finally cinnamon to russet, "sometimes unchanging when bruised but usually tending to stain tawny to fulvous from handling", when dried vinaceous-red to vinaceous-brown; usually covered with a network of rhizomorphs that are conspicuous at first but less so when old "(as the surface becomes the same color as the rhizomorphs)"; peridium sometimes showing a tendency to flake off, especially when dried, exposing pale ochraceous areas, peridium is basically thin but rhizomorphs become interwoven so that it is rather thick in some areas, (Smith(30)), 2-8cm across, "yellow to tawny or ochraceous when young", but usually overlaid with brown to reddish brown rhizomorphs, "often mottled with red or reddish brown areas" (especially when old), "sometimes reddening somewhat when bruised or discoloring brown to rusty brown", (Arora), white and quickly passing through pale luteous stage, then tawny yellowish and finally cinnamon brown, (States), bright yellow when young "with yellow rhizomorphs appressed to form a network over the entire surface, the outer rhizomorphs and peridium soon darkening to red or reddish brown"; often fruits in clusters, (Trappe, M.(3))

Stem:
columella absent (Arora), free dark brown rhizomorphs at base (States)

Chemical Reactions:
FeSO4 on surface greenish to dark olive (rarely scarcely reacting), "KOH slowly tawny to reddish-brown or no reaction (reaction usually slow)", (Smith(30))

Interior:
"consistency when dried somewhat friable and easy to section"; "white becoming olivaceous to olive-brown" but near cinnamon-buff when dried; chambers moderately large, (Smith(30)), "firm or spongy becoming tough as it dries"; pallid to grayish becoming olive or olive-brown when old; minutely chambered, (Arora), chambers 2-4 per mm, (States), white at first, becoming tan, when mature olive to olive-brown or brown, (Trappe, M.(3))

Odor:
none at first, when old acid to acid metallic at times, (Smith(30)), faint and unpleasant (States), mild (Trappe, M.(3))

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

Microscopic:
spores 6-8 x (1.7)2-2.5(3) microns; subhymenium cellular; hyphae of tramal plates thin-walled (under 0.5 microns thick) as revived in KOH; "peridium of rhizomorphs incorporated in a layer of appressed hyphae", hyphal incrustations and interhyphal debris vinaceous red (magenta) in KOH, "some cells inflated to 20 microns but no pockets of sphaerocysts seen, ground hyphae (excluding those of the rhizomorphs) 3-10 microns wide", (Smith(4)), spores 6-8 x (1.7)2-2.5(3) microns, narrowly oblong, smooth, in Melzer''s reagent yellowish-transparent to ochraceous and none seen with a false septum, in KOH colorless when young, yellowish at maturity, spores thin-walled, basal scar small and indistinct; basidia 6-spored and 8-spored, 12-20 x 5-7 microns, "ellipsoid to slightly clavate, thin-walled, collapsing", colorless or in chambers near peridium occasionally somewhat vinaceous in KOH; paraphyses resembling basidioles, thin-walled, colorless, collapsing; cystidia none; subhymenium "very indistinct and refractive, cellular layer consisting of basal cells of the hymenial elements"; tramal plates composed of hyphae that are subparallel to interwoven, gelatinous-refractive, smooth, thin-walled; peridium "of appressed-interwoven hyphae and rhizomorphs, the fundamental peridial hyphae usually dark vinaceous-red as revived in KOH from pigment deposits and wall incrustations, the rhizomorphs basically ochraceous in KOH but in some sections entirely vinaceous-red, or in others some red and some merely ochraceous (where there are no pigment pockets, some only red around the periphery)", "no sphaerocysts present but occasional inflated cells up to 15-20 microns present on some hyphae, hyphae mostly 3-10 microns diam and cells uninflated and thin-walled"; all tissues inamyloid; clamp connections absent, (Smith(30)), spores 5.5-8.0 x 2.0-2.8 microns, oblong to elliptic, with two droplets, (States)