|California Fungi—Postia leucospongia
(Photo: © Michael Wood)
(Cooke & Hark.) Jülich
Mycotaxon 22: 365. 1985.
The snow in the background shows this fungus' habit of fruiting near melting snow banks
(Cooke & Hark.) Bondartsev & Singer;
(Cooke & Hark.) Gilb. & Ryvarden;
(Cooke & Hark.) Murrill;
Cooke & Hark.;
Cooke & Harkn
Fruiting body annual, effused-reflexed, shelving, 4.0-13.0 cm long, up to 5.0 cm in width; cap shell-shaped, the margin persistently incurved, arching over, and partially covering the pore surface; upper surface when young covered with a whitish matted-tomentum, becoming buff to pale-tan in age, eventually nearly glabrous to sometimes wrinkled; context approximately 1.0-2.0 cm thick, two-layered, the upper half tan, cottony, soft, the lower portion whitish and rigid; odor not distinctive; taste acrid to somewhat bitter.
Pores 2-3/mm, angular, the edges minutely fringed in youth, dentate in age (use hand lens), at first cream, pale-tan in age; tube layer up to 5.0 mm thick, becoming hard/rigid at maturity.
Spores 4.5-6.5 x 1.0-1.5 µm, narrowly-oblong to sausage-shaped, smooth, thin-walled, hilar appendage not obvious, inamyloid; spore deposit not seen.
Solitary or imbricate in small groups on wood of montane conifers, particularly red fir (
) and Lodgepole pine (
); fruiting in late spring, dried fruiting bodies persisting through the summer; common.
Inedible; tough, unpleasant taste
is a snowbank species found throughout the montane regions of the western United States. It occurs commonly in the spring at higher elevations of the Sierra Nevada and presumably the Coast Ranges as well. An important fieldmark is the soft, white, upper surface which partially encloses the pore layer.
is sometimes found fruiting with another annual polypore,
. The distinctive orange hues of the latter, however, make it unlikely to be confused. Both species have fruiting bodies with a foam-like quality and are surprisingly light for their size.
North American Fungi. Grevillea 11: 106-111. (
Desjardin, D.E., Wood, M.G. & Stevens, F.A.
(2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Gilbertson, R.L. & Ryvarden, L.
(1986). North American Polypores, vol. 1. Fungiflora: Oslo, Norway. 433 p.
(2017). Polypores of British Columbia (Fungi: Basidiomycota). Province of British Columbia: Victoria, BC. 260 p.
Lindsey, J.P. & Gilbertson, R.L.
(1978). Basidiomycetes that Decay Aspen in North America. J. Cramer: Vaduz. 406 p.
(1953). The Polyporaceae of the United States, Alaska, and Canada. University of Michigan Press: Ann Arbor, MN. 466 p.
Other Descriptions and Photos
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The Fungi of California
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