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

Summary:
Truncocolumella citrina is characterized by 1) a spherical to irregular fruitbody that is yellowish to olive, dry, and smooth or sometimes cracking, 2) a small-chambered spore mass that is firm to gelatinous, and yellow-brown to olive-gray, 3) a yellow columella that is stump-like to branched, often forming a short thick stem, 4) growth in duff or slightly projecting, under Douglas-fir, and 5) microscopic details including elliptic, smooth spores from 4-spored basidia. Smith described the var. separabilis, distinguished by the tendency of the spore mass to separate from the stem-columella and from the plate-like branches of the columella, the distinct tubular nature of the spore mass, and the rather strong pseudoamyloid reaction of the spores in Melzer''s reagent, and noted also an interwoven arrangement of the hyphae of the tramal plates. Truncocolumella citrina is abundant among false truffles in the Pacific Northwest (Trappe(13)).

Truncocolumella citrina is found from BC to northern CA to the Rocky Mountains, (Trappe(13)). Collections of Truncocolumella citrina var. citrina were examined from WA, OR, ID, and CA, and it is said to occur "throughout the Pacific Northwest, late summer and fall, often rather common", (Smith(29)). There are collections from BC at the Pacific Forestry Centre and the University of British Columbia, and collections at Oregon State University from BC, WA, OR, ID, CA, and MT.

Outer Surface:
2-5(7)cm broad, 1.5-5cm high, "irregularly rounded to oval, bulblike, lobed, or kidney-shaped"; sometimes whitish when very young but soon becoming yellow to ocher, greenish yellow, or grayish olive; "smooth or sometimes cracking to form a few scales or patches", (Arora), 2-5(7)cm broad, 1.5-5cm high, "whitish when immature and not exposed to light", becoming yellow ocher to olive-fuscous at maturity, (Smith(4)), 2-3cm across, 1.5-4cm high, obovate, subellipsoid, spherical, depressed-spherical to kidney-shaped or heart-shaped; pale greenish yellow darkening to olive-fuscous when old, ("immature stages sometimes whitish" before exposure to light), drying pale yellow to dull greenish yellow, or, where bruised, "old gold" (Ridgway color); typically unpolished and dry, (Smith(29)), yellow; felty, (Trudell)

Stem:
stem "often (but not always) present as a short, thick, narrowed base"; columella present also, either stump-like or branched and extending into the spore mass for a considerable distance; yellow to buff; flesh in stem yellow to buff and firm, (Arora), stem-columella much-branched, with stump-like base; stem-columella and its base bright yellow, (Smith(4)), "columella stump-like to dendroid, the base and branches of pallid yellowish tissue composed of loosely arranged hyphae" 4-7 microns wide, "sterile base merely the broad base of the columella, citrine yellow, usually arising from yellow rhizomorphs", (Smith(29)), columella pale yellow to yellow (Trudell)

Interior:
"composed of small empty tubular chambers, completely enclosed by the peridium", firm when young but often quite gelatinous when old; "yellow-brown to olive-gray", becoming darker (sometimes blackish) when old, (Arora), "chambered, the chambers small, tubular", (Smith(4)), rubbery; "at first white, later gray then brown", (Trappe, M.(3))

Odor:
none (Miller)

Taste:
unknown (Miller)

Microscopic:
spores 6-10 x 3.5-5 microns, elliptic, smooth, yellowish to light brown, (Arora), spores 6.5-9.7 x 3.6-4.2(5) microns, elliptic to suboval, smooth, "yellowish in KOH, darker yellow in Melzer''s reagent (in mass ochraceous tawny)", "thin-walled or the wall scarcely thickened and showing no differentiation of a pore at spore apex"; basidia 4-spored, 23-26 x 6-7 microns, narrowly clavate, the sterigmata 5-6 x 2 microns, conic; pseudoparaphyses abundant, 18-30 x 10-17 microns, broadly clavate to subspherical, subcylindric, or subfusoid (almost cystidioid in some); cystidia not seen except for large pseudoparaphyses; subhymenium cellular; tramal plates of hyphae 3-6(8) microns wide, subgelatinous, divergent from a thin central strand; peridial epicutis "possibly a collapsed trichodermium", in revived sections apparently consisting of hyphae 3-15 microns wide, loosely arranged, more or less appressed, "with thin, non-incrusted walls yellowish in KOH"; interior to this a body of hyphae 5-9 microns wide, interwoven-subradial, "slightly gelatinous to floccose in KOH, and almost colorless"; clamp connections readily observed at the cross walls, (Smith(29))