What You Should Know
Leucangium carthusianum is a species of an ascomycete fungus. It is found in the Pacific Northwest region of North America, where it grows in an ectomycorrhizal association with Douglas-fir. Mature fruiting bodies can be dug up mostly during winter, but the season can extend from September through April. On the outside, the fruit bodies are dark brown and rough to smooth. They are sometimes mistaken for coal lumps. Inside, the gleba is gray to brownish and separated into pockets by veins. The odor is pungent and fruity, usually resembling a pineapple.
Leucangium carthusianum is a good edible mushroom; it can be prepared similarly to Oregon White and European truffles; it is typically shaved raw on top of a dish to add its complex musky aroma.
Picoa carthusiana Tul. & C.Tul. (1862) is a synonym.
Other names: Oregon Black Truffle.
Leucangium carthusianum Mushroom Identification
Produced underground and have a dark peridium, composed of isodiametric cells raised in warts overall or patches.
The gleba is solid, firm, whitish to yellowish gray, with grayish mottling of fertile pockets surrounded by whitish sterile, undifferentiated veins.
Ellipsoid in form and are exceptionally large (60–90 mm).
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.
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.
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Photo 2 - Author: heatherdawson (Attribution-NonCommercial 4.0 International)
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