Geopora cooperi

Description

Geopora cooperi is a species of fungus in the family Pyronemataceae. It has a fuzzy brown outer surface and an inner surface of whitish, convoluted folds of tissue. Widely distributed in the Northern Hemisphere, the species has been recorded from Asia, Europe, and North America.

G. cooperi is not closely related to the true truffles, i.e. Tuber species. A major difference is the spores which are smooth and forcibly discharged, while those of Tuber species are ornamented and not ejected from the ascus. Of the many truffle-like fungi in California, Geopora cooperi most closely resembles Hydnotrya cerebreformis which also has a pubescent exterior. The surface hairs of Hydnotrya cerebreformis, however, are very short and fine, not coarse. This species also differs in having a strong garlic odor and globose spores with rounded warts. Geopora cooperi f. gilkeyi differs from f. cooperi in having ovate to subglobose spores.

Geopora cooperi is a snowbank mushroom, as it commonly occurs after the snow has melted.

First described by American mycologist Harvey Willson Harkness in 1885, the fungus is named for the original collector, J.D. Cooper.

Common names: Cooper'S Truffle, Fuzzy False Truffle, Fuzzy Truffle, Pine Truffle.

Mushroom Identification

1. Ecology

   Precise ecological role undocumented, but probably at least facultatively mycorrhizal, growing alone or gregariously, underground or partially submerged, under conifers (but also reported under aspens and eucalyptus); summer and fall; subalpine western North America.

2. Fruiting Body

   3-6 cm across; shaped more or less like a ball or a glob; without a stem.

3. Outer Surface

   Lumpy to nearly brain-like; dry; densely covered with very fine, brown hairs; medium to dark brown.

4. Interior

   Consisting of many folded, contorted, whitish layers of flesh that often have brownish edges; the layers usually touching one another, but not becoming fused; flesh whitish, sometimes staining a little yellowish when sliced.

5. Odor and Taste

   Odor not distinctive, or sour and reminiscent of bad apple cider; taste not distinctive.

6. Microscopic Features

   Spores 19-22 x 13.5-16 µ; ellipsoid; smooth; usually uniguttulate with one large oil droplet; hyaline in KOH. Asci eight-spored; up to 250 x 20 µ. Paraphyses cylindric with subclavate to irregularly thickened apices; hyaline in KOH; smooth; 5-7 µ wide. Excipular hairs 9-14 µ thick; dark brown to yellow-brown in KOH; walls about 1.5 µ thick; septate; encrusted.

Photo sources:

Photo 1 - Author: Ron Lawrence (Rondango) (CC BY-SA 3.0)

Photo 2 - Author: user: jrussula (CC BY-SA 3.0)

Photo 3 - Author: Jonathan Frank (jonagus) (CC BY-SA 3.0)