|California Fungi—Pluteus petasatus
(Photo: © Fred Stevens)
Hyménomycètes de France: 142. 1838.
Cap 5-13.5 cm broad, convex to convex-umbonate, expanding to nearly plane, at maturity the disc sometimes depressed or raised; margin in youth, incurved, then decurved, finally plane; surface sticky when moist, otherwise dry, glabrous when young, often shiny, cream-colored with pale innate, brown fibrils concentrated at the disc, the latter occasionally becoming fibrillose to squamulose; in dry weather the cap sometimes squamulose overall; context white, unchanging, soft, up 1.5 cm thick, thin near margin; odor and taste of radish.
Gills free, crowded, broad, pallid, becoming cream to pinkish, finally salmon pink; not marginate; lamellulae up to four-seried.
Stipe 5-9 cm long, 1-1.5 cm thick, straight, the apex and base often enlarged, fleshy, solid at maturity; surface longitudinally striate at the apex, white, elsewhere smooth to slightly wrinkled, in age brownish fibrils sometimes developing at the base; partial veil absent.
Spores 5.5-7 x 4-5 µm, broadly ellipsoid to ovoid, smooth, with granular contents; spore print salmon-pink.
Clustered, less commonly solitary, on rotting chips, woody debris or logs; fruiting in late summer in watered areas or after the fall rains.
is unusual in its clustered fruiting habit. Also characteristic is a relatively smooth, sometimes shiny cap that is pallid at the margin and brownish at the disc. A related, more common species is
. It is distinguished by an entirely brown cap. Volvariella speciosa is a distant cousin similar in stature, cap, and spore color, which may also fruit in wood chips. It is easily told from
by the presence of a volva. Another look-alike occasionally found in wood chips is
. It has a similar colored, though not nearly as shiny cap, and can be differentiated by a partial veil and at maturity, free chocolate-colored gills.
(1986). Mushrooms Demystified. Ten Speed Press: Berkeley, CA. 959 p.
Banerjee, P. & Sundberg, W.J.
(1995). The Genus
(Pluteaceae, Agaricales) in the Midwestern United States. Mycotaxon 53: 189-246.
Bas, C., Kyper, T.W., Noordeloos, M.E. & Vellinga, E.C.
(1990). Flora Agaricina Neerlandica -- Critical monographs on the families of agarics and boleti occuring in the Netherlands. Volume 2. Pluteaceae, Tricholomataceae. A. A. Balkema: Rotterdam, Netherlands. 137 p.
Breitenbach, J. & Kränzlin, F.
(1995). Fungi of Switzerland. Volume 4: Agarics (2nd Part). Entolomataceae, Pluteaceae, Amanitaceae, Agaricaceae, Coprinaceae, Strophariaceae. Verlag Mykologia: Luzern, Switzerland. 368 p.
Desjardin, D.E., Wood, M.G. & Stevens, F.A.
(2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
(1986). British Fungus Flora: Agarics and Boleti. Vol 4. Pluteaceae:
. Royal Botanic Garden: Edinburgh, Scotland. 99 p.
Siegel, N. & Schwarz, C.
(2016). Mushrooms of the Redwood Coast. Ten Speed Press: Berkeley, CA. 601 p.
(1956). Contributions Towards a Monograph of the Genus
. Trans. Br. Mycol. Soc. 39(2): 145-232.
Other Descriptions and Photos
Arora (1986): p. 255 (D & P)
(1990): P. 37 (D & I)
: p. 62 (D & CP)
Orton: p. 24 (D), fig. 46 (I)
Phillips: p. 138 (CP), p. 139 (D)
(D=Description; I=Illustration; P=Photo; CP=Color Photo)
The Fungi of California
Copyright © 1999-2020 Michael Wood & Fred Stevens