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

Summary:
Features include 1) an irregularly lobed, brown fruitbody with a thin outer layer that soon wears away to expose the cavities of the firm, rubbery, ochraceous-tawny to grayish brown spore mass, 2) often a mycelial cord at base, 3) a distinct, slender, branching columella, 4) a strong odor when old, 5) a location underground or on the ground under mountain conifers, and 6) microscopic characters including spores measuring 10-15 x 6-9 microns with 7-10 longitudinal or oblique ridges, and basidia that are mostly 2-spored. It is abundant among false truffles in the Pacific Northwest.

Distribution in the Pacific Northwest is from BC to northern CA (Trappe(13)). It is common in the mountains of the western United States (Trappe, M.(3)). It has been reported to Oregon Truffling Society for BC and OR, and by J. Smith et al. from OR. Paul Kroeger deposited a collection from BC at the University of British Columbia.

Outer Surface:
(1)2-9cm across, "round to elongated or irregularly knobby (potato-like)"; pallid when very young, soon becoming light brown to ocher to rusty brown or dull brown; peridium "very thin, soon wearing away to expose the spore-bearing cavities", (Arora), 10cm across and about 3cm high, irregularly lobed, nearly flat above and below; "Dresden brown" to "mummy-brown"; peridium (or rather the outer part of the gleba) 0.014-0.016cm thick, (Dodge)

Stem:
often with a mycelial cord at base; "distinct columella usually present and often penetrating to the centre of the spore mass", thin, often branched; whitish or translucent, (Arora), sterile base not prominent, columella very slender, branching, (Dodge)

Interior:
spore mass when fresh firm, rubbery, crisp, not fragile; ocher brown to rusty brown to dull cinnamon to dull brown at maturity; composed of numerous irregularly shaped cavities, 0.05-0.3cm, (Arora), "ochraceous-tawny" to grayish brown; cavities small, empty, (Dodge), firm, rubbery; cinnamon-colored "with cartilaginous veins and an inconspicuous to distinct white to translucent columella", (Trappe, M.(3))

Odor:
often strong when old, sometimes of decaying onions, (Arora), very strong when old, like sour milk, (Miller), sweet-oily, may become nauseating, (Trappe, M.(3))

Taste:
mild (Miller)

Microscopic:
spores 10-15 x 6-9 microns, elliptic, longitudinally grooved, rusty-brown to ocher-brown under the microscope, (Arora), spores 9-13 x 6.5-8 microns, elliptic to oboval, "with 7-10 longitudinal or oblique striations, sometimes slightly warted", "ochraceous-tawny", with one to several droplets; basidia mostly 2-spored, "arising from erect, septate hyphae 16 x 6-7 microns, ovoid", sterigmata "filiform, 7-10 microns long"; septa 120-400 microns thick, colorless, "composed of more or less gelified hyphae parallel with the hymenial surface"; "peridium or rather the outer portion of the gleba 140-160 microns thick, composed of hyphae with greatly gelified walls enclosing dirt in the outer portion", (Dodge), spores 10-16 x 7-9 microns, elongate lemon-shaped with longitudinal ridges (Trappe, M.(3))