Gymnopilus ventricosus
Mycol. Mem. 3: 20. 1969.
Common Name: jumbo gym
Misapplied Names: Gymnopilus spectabilis (Fr.) A.H. Smith; Gymnopilus junonius (Fr.) P. D. Orton
Synonym: Pholiota ventricosa Earle
Cap 7-20 cm broad, convex with incurved margin, nearly plane in age; surface dry, yellowish-orange to orange with fine brown scales; flesh thick, yellow, turning red in KOH; odor mild to pungent, taste bitter.
Gills close, adnate, notched, to slightly decurrent; yellow, becoming orange.
Stipe 7-21 cm long, 1-4 cm thick, yellow-orange, lighter than the cap, streaked with brown fibrils, equal, club-shaped, or ventricose, usually narrowed at the base; partial veil membranous, yellowish, forming a usually persistent superior ring.
Spores 7.5-10 x 4.5-6 µm, roughened, elliptical. Spore print rusty-orange.
Fruiting from early fall to mid-winter in clusters on stumps and logs of both hardwoods and conifers.
Inedible, very bitter.
Gymnopilus ventricosus is quite distinctive as its yellowish-orange clustered fruitings are often massive with dinner plate-sized mushroom caps. The combination of a clustered habit on wood, orange cap, well developed ring, bitter taste and rusty spores make it easy to identify.
This may be a species complex, with more than one species occurring in California. Traditionally called Gymnopilus junonius (=Gymnopilus spectabilis), but that is a European species not known to occur in North America.
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Arora, D. (1986). Mushrooms Demystified. Ten Speed Press: Berkeley, CA. 959 p.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Hesler, L.R. (1969). North American Species of Gymnopilus. Hafner Publishing Company: New York, NY. 117 p.
Lindsey, J.P. & Gilbertson, R.L. (1978). Basidiomycetes that Decay Aspen in North America. J. Cramer: Vaduz. 406 p.
Siegel, N. & Schwarz, C. (2016). Mushrooms of the Redwood Coast. Ten Speed Press: Berkeley, CA. 601 p.
Smith, A.H. (1949). Mushrooms in their Natural Habitats. Sawyer's Inc: Portland, OR. 626 p. (PDF)
— young sporocarps
— big mushrooms!
