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

Summary:
Also listed in Truffles etc. category. Features include 1) an irregular to top-shaped cap that is yellowish brown to reddish brown sometimes with yellowish or reddish tinges, 2) yellow flesh that turns blue when exposed, 3) yellowish tubes that are irregular and not vertically oriented, 4) angular pores that are yellow or tinged orange and turn blue when bruised, 5) a short stem that is yellow with reddish tinges and turns blue when bruised, and 6) growth under conifers, often partly buried. The taxon will likely be recombined as one or more species in a bolete genus. Var. flammeus, known from Idaho, grows on the ground under fir and has a pale golden cap with red blotches, bright red pores when young, and shorter spores 11-14 x 7-9 microns, (Bessette). Var. flammeus may occur elsewhere in the Pacific Northwest and other varieties are not well documented. Among false truffles in the Pacific Northwest, G. turbinatus is common, (Trappe(13)).

Gastroboletus turbinatus is found in WA, OR, and ID, and is apparently widely distributed in the western US and also found in MO, (Smith). It is also found in CA (Castellano). There are BC collections at the University of British Columbia.

Cap:
2-5(8)cm across, convex to slightly depressed to irregular; usually brown to reddish brown to bright yellow with red or brown spots and stains; "dry, minutely velvety, often pitted or wrinkled", (Arora), 2-5(8)cm across, convex becoming flat or slightly depressed; bister to mummy-brown, golden-yellow or bay-red, or with a reddish to orange-salmon tinge at least along marginal area; dry, velvety, when old subtomentose [somewhat tomentose], (Smith)

Flesh:
soft; yellow, typically bruising blue quickly; in stem base often reddish, (Arora), flesh "yellow in the peridium, often partly pinkish in the stipe-columella, tending to stain blue when injured and later becoming red to brownish in these areas, especially on drying", (Smith)

Pores:
"pinkish to reddish, orange, or yellow", typically turning blue quickly when bruised; tubes irregular and sinuous or oriented at various angles other than vertical, greenish yellow to yellow, (Arora), round at first and about 0.5mm across, when old with large angular depressions reaching 1 mm across; tube chambers reaching 1-3cm or more in length but diminishing in length in both directions from the place where they are longest, "strongly projecting beyond the peridium or remaining covered by its extended thin portion, either strongly depressed or nearly free from the apex of the columella, more rarely broadly attached to the columella"; interior of gleba yellow and quickly turning blue on exposure, pores in some specimens becoming reddish at mouths when mature or when old, (Smith), 1-2 per mm, angular, "covered by a thin membrane at first", surface irregular and uneven; yellow, sometimes tinted orange, quickly turning blue when bruised; "tubes 1-3cm long, irregular and not vertically arranged", depressed near stem, (Bessette)

Stem:
1-4(7)cm x 1-2.5cm, equal or narrowing at base, often protruding only a short distance below tubes, solid; "yellow or with reddish streaks or granules or colored like the cap", sometimes reddish when old and often reddish at base; dry, (Arora), 1-2(7)cm x 0.8-2cm, equal or narrowing downward, often not projecting much below gleba, solid; unpolished in upper part, "yellow or more orange-yellow to reddish toward the base, turning blue when bruised, sometimes finally becoming reddish"; frequently finely rivulose [with river-like lines] "because of the cracking of a brownish to reddish layer, the layer finally breaking up into minute points, at times brown-furfuraceous in a narrow zone", stem finally becoming bald; no veil, (Smith)

Odor:
slight and insignificant (Smith)

Taste:
slight and insignificant (Smith)

Microscopic:
spores (9.5)13.5-18 x 6.5-9.5 microns, elliptic to spindle-shaped, smooth, brown or golden, (Arora), spores (9.5)13.5-18(20) x (5.5)6.5-9.5 microns, elliptic to oblong or slightly oval, honey-colored, often with a fulvous tinge, "walls simple at first, later thickening and becoming 3-layered", "apex obtuse to acute and the wall there either continuous or showing a slight pore"; basidia mostly 4-spored but sometimes with 1, 2 or 3 spores, 35-38 x 9-14 microns, "rather voluminous, vesiculose-pedicellate to clavate", colorless or yellow in KOH, basidioles scattered, variable in size or shape, about 33 x 9 microns, mostly somewhat clavate, colorless; "pseudoparaphyses similar in size and shape to the basidioles but without protoplasmic content and hence not likely to produce spores"; cystidia rare but present in interior as well as pores, 35-60 x 9.5-17 microns, ventricose-mucronate to more often ventricose in middle and ampullaceous-pedicellate, often with a long thin neck, colorless, later either colorless or golden yellow to brownish, apex usually obtuse; clamp connections absent, (Smith)

Spore Deposit:
not obtainable (Arora)