E-Flora BC: Electronic Atlas of the Flora of British Columbia

Agaricus silvaticus Schaeff. ex Secr.
red-staining mushroom
Agaricaceae

Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.

Introduction to the Macrofungi

© Michael Beug  Email the photographer   (Photo ID #15223)

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Distribution of Agaricus silvaticus
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Species Information

Summary:
Features include medium size, cap with ocher to dark brown scales on white ground, flesh that stains reddish when cut or bruised, white to pale pink gills, white stem with bulbous base, and habitat under conifers. Historically in Europe there has been confusion about what the description of the species is (some concepts for instance include small-spored A. haemorrhoidarius and/or large-spored A. langei - see NOTES on A. haemorrhoidarius, or include A. annae Pilat), and there has consequently been debate about its status in the Pacific Northwest. A species that does not stain red has also been called A. silvaticus in the western United States and was renamed A. helodes by Isaacs but never validly published (its flesh has a phenol odor when freshly cut, and does not redden, but when broken or rubbed turns yellow in spots and then becomes umbrinous, or when untouched slowly turns umbrinous). Isaacs gives a description of Agaricus silvaticus Schaeff. ex Secr. based on Moeller 1950 (paraphrased below) but did not find the taxon in WA; on the other hand he says what he calls A. hemorrhoidarius may best be regarded as a small-spored variation of A. silvaticus Schaeff. ex Secr. Phillips is describing a taxon found under pine in eastern North America. A. silvaticus has been reported at least from BC without details of staining (Melburn 1967, Lowe(1) (1969), Bandoni(1) (1976), and from WA and CA (Smith(15), as Agaricus silvaticus Fr., the flesh "slowly becoming reddish brown"). Oregon State University has collections from OR., CHEMICAL REACTIONS not yellowing with KOH (Chariton), Schaeffer reaction negative [Schaeffer's reaction is red or orange color reaction when aniline plus nitric acid applied] (Isaacs)
Cap:
5-10cm across, convex, often with a slightly flattened or somewhat umbonate center; fulvous ("tawny olive") or nut brown ("fawn color"); "either predominantly densely fibrillose or fibrilloso-squamulose outside the disc, though often with sparse light brown fibrillose scales on a lighter ground", (Isaacs), 4-10cm across, convex with a slightly flattened cap center; "reddish brown to umber on a paler background; with distinct, scattered, pointed scales", (Phillips)
Flesh:
thin, dry; whitish, pale crimson ("pinkish vinaceous") and dark purple ("deep hellebore red") in spots when cut, "especially in the outer layer at the top of the stem and just above the gills", (Isaacs), white, bruising red on cutting, (Phillips), thick, firm; stains red to red-brown when cut, especially just above gills, and outer layer in top of stem, (Chariton)
Gills:
free, crowded, narrow; never bright red, but light grayish brown ("tilleul buff") tinged faintly with flesh color, eventually dark chocolate brown, with sterile, light colored, densely floccose edge, (Isaacs), free; slightly pink then chocolate brown; edges paler, (Phillips)
Stem:
6-10cm x 1-1.2cm, cylindric with round bulbous base, hollow; whitish, but soon turning gray with the ring; bald above the ring, below it delicately white floccose-squamulose, (Isaacs), 5-10cm x 0.5-1.5cm, bulbous; white, finely scaly to smooth, (Phillips)
Veil:
ring sheathed and striate on upper surface, fairly rigid, with white squamulose underside, at length turning gray, (Isaacs), "ring large, white, with underside slightly woolly-floccose", (Phillips)
Odor:
acidulous (Isaacs), pleasant, slightly anise-like, (Phillips)
Taste:
pleasant (Phillips)
Microscopic spores:
spores 4.5-6 x 3-3.5(4) microns, egg-shaped, 1 droplet; basidia 4-spored, 20-30 x 5-7 microns, sterigmata 2-3 microns long; cheilocystidia numerous, 17-34 x 7-13(18) microns, balloon-shaped - clavate, colorless or brown, (Isaacs), spores 4.5-6 x 3-3.5 microns, oval, (Phillips), spores 4.5-6 x 3-3.5 microns, (Moser for A. silvaticus Schaeff. & Secretan), spores 6-8 x 3-4 microns (Hotson for A. silvaticus Schaeff.)
Spore deposit:
dark brown ("mummy brown"), (Isaacs), deep brown (Phillips)

Habitat / Range

gregarious in conifer woods, stem often deeply rooted in needles, August to October, (Isaacs, following Moeller), under pine, September to October, (Phillips), summer, fall, (Buczacki)

Synonyms and Alternate Names

Agaricus sylvaticus

Taxonomic and Nomenclatural Links


Genetic information (NCBI Taxonomy Database)
Taxonomic Information from the Missouri Botanical Garden
Index Fungorium
Taxonomic reference: Mycographie suisse, Vol. 1, 1833 sensu Moeller 1950 and Pilat 1951, non ss. Murrill 1912, Zeller 1938, A.H. Sm. 1940

Additional Range and Status Information Links

Edibility

yes, good, (Phillips)

Additional Photo Sources

Related Databases

Species References

Isaacs(1) (based on Moeller 1950, with colors in double quotation marks from Ridgway), Phillips(1)*, Miller(14)*, Kibby(1)*, Courtecuisse(1)*, Ammirati(1)*, Hotson(1), Barron(1)*, Chariton(1), Smith(15), Breitenbach(4)*, Bandoni(1), Lowe(1), Buczacki(1)*

References for the fungi

General References