Leucangium carthusianum (Tul.) Paol.
Oregon black truffle
Morchellaceae
Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.
Introduction to the Macrofungi
Oregon black truffle
Morchellaceae
Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.
Introduction to the Macrofungi
Species Information
Summary:
Features include 1) a somewhat spherical to slightly irregular fruitbody that looks like animal dung, 2) blackish color, 3) a minutely warted exterior, 4) a spore mass that is whitish becoming grayish green with whitish streaks, sometimes exuding a clear latex that stains white paper pale violet when left overnight, 5) growth in humus or soil in the woods, and 6) microscopic characters including large, smooth, lemon-shaped to spindle-shaped spores and typically 8-spored asci. It was originally described from France but less frequent there than in the Pacific Northwest, (Trappe, M.(3)). Pacific Northwest collections may actually be a different species from the European one They are common among truffles in the Pacific Northwest, (Trappe(13)).
Interior:
more or less solid, "grayish green marbled with whitish streaks", (Smith), "more or less solid, composed of large pockets of fertile tissue marbled with paler (whitish to buff) sterile veins; fertile tissue whitish to buff when young but becoming grayish-green to greenish-blue in age, sometimes exuding a clear latex when fresh which slowly (overnight) stains white paper pale violet", (Arora), "solid, comprising fertile tissue streaked with paler sterile veins"; fertile tissue "whitish to buff becoming grayish green or greenish blue; sometimes exudes a clear milk which slowly stains white paper light mauve", (Phillips), solid; gray to olive or brownish; "separated into pockets by pallid sterile veins", (Trudell), solid, firm; "gray pockets of spore-bearing tissue separated by white veins", (Trappe, M.(3))
Odor:
fungoid, pungent, or slightly garlic-like, (Miller), "strong pungent fruity (often like pineapple)" when mature, (Trudell), pleasant and fruity (most often resembling pineapple) when young, becoming increasingly pungent and earthy when old, (Trappe, M.(3))
Taste:
"pleasant mild" (Miller)
Microscopic:
spores 74-85 x 24-35 microns, spindle-shaped to lemon-shaped, "greenish yellow to honey color, with distinct apiculus at one or both ends"; asci 8-spored, spherical-ellipsoid, (Smith), spores (56)74-84 x 20-35 microns, lemon-shaped or spindle-shaped, smooth, typically with one giant oil droplet when mature, pallid to greenish yellow becoming brown when mature; asci "typically 8-spored, imbedded in the tissue (not forming a palisade)", (Arora), spores 52-109 x 19-42 microns, olive-colored, apiculate, (Castellano), spores 65-80 x 25-40 microns, fusoid, smooth, (Trappe, M.(3))
Notes:
Leucangium carthusianum is found from southern BC to western OR at low elevations, and also found in southern Europe, (Trappe(13)). There are collections from BC deposited at University of British Columbia. It occurs in WA (M. Beug, pers. comm., Colgan(2)).
EDIBILITY
good (Phillips)
Habitat and Range
SIMILAR SPECIES
Kalapuya brunnea (often called Oregon brown truffle), found in young Douglas-fir stands in the Cascade Range in OR and Coastal Ranges of OR and northern CA, has a reddish-brown exterior with a granular texture and a grey marbled interior, a garlicky-cheesy odor, and different spores (smaller with many smaller droplets as well as the central one), (Trappe, M.(4)). Tuber species are similar in having a solid interior, but in Leucangium carthusianum the spore mass is greenish to grayish when mature, the exterior minutely warted, and the spores are large, smooth, and spindle-shaped, (Arora). Tuber melanosporum, the European black truffle, and Tuber indicum, the Asian black truffle have become established and have completed their life cycle in North American soils, but have not been shown to occur in forests away from truffle farms except for one collection of Tuber indicum in Oregon, (Bonito(2)).Habitat
under Douglas fir, fall and winter, (Smith), single, scattered or in small groups in soil and humus in woods, (Arora), several to many, in soil under conifers or oaks; early spring and summer (Miller), with relatively young Pseudotsuga menziesii (Douglas-fir), often 10-25cm deep in the soil; September to February, (Trappe, M.)
Status Information
Synonyms
Synonyms and Alternate Names:
Oligoporus stipticus (Pers.: Fr.) Gilb. & Ryvarden North
Picoa carthusiana Tul.
Tyromyces stipticus (Pers.) Kotl. & Pouzar