Felt-ringed agaricus

Agaricus hondensis

''Agaricus hondensis'', commonly known as the felt-ringed agaricus, is a species of fungus in the family Agaricaceae. The species was officially described in 1912 by mycologist William Alphonso Murrill, along with three other ''Agaricus'' species that have since been placed in synonymy with ''A. hondensis''. Found in the Pacific Northwest region of North America, ''A. hondensis'' fruits in the fall under conifers or in mixed forests.

The fungus produces fruit bodies with white to gray-brown caps up to 15 cm in diameter covered with pale pinkish-brown scales that darken in age. The tightly-packed gills on the cap underside are initially white before becoming pinkish, lilac-gray, and finally brownish as the spores mature. The stout stipe is bulbous and has a thick, white, felt-like ring. The mushroom is poisonous, and causes severe gastrointestinal upset if consumed. It has an unpleasant odor similar to phenol or creosote, and develops a soapy-metallic taste when cooked. ''Agaricus hondensis'' can be distinguished from similar ''Agaricus'' species by differences in geographic range, habitat, staining reaction, and odor.
A Felt-ring Agaricus. Supposedly a common mushroom found in the Pacific Northwest in mixed forests. It usually fruits in fall or winter. It is poisonous to “most people“. Wonder how they determined that? https://www.jungledragon.com/image/86089/the_caps_of_agaricus_hondensis.html Agaricus hondensis,Canada,Fall,Felt-ringed Agaricus,Geotagged

Appearance

The cap is initially convex before flattening out, and reaches a diameter of 6–15 cm . The dry and smooth cap surface is whitish or has pale pinkish-brown to pinkish-gray to fawn-colored flattened fibrils or fine fibrillose scales . In maturity, the fibrils usually darken to brown, reddish-brown, or reddish-gray, but in one northern form the fibrils are darker brown from the beginning. The flesh is thick and white. When bruised or injured, the flesh either does not change color, or may stain pale yellowish, then often slowly discolors pinkish. The odor of the crushed flesh is mild or faintly phenolic, but is usually distinctly phenolic in the base of the stipe.

The gills are initially pale pinkish to pinkish-gray before becoming brown, then chocolate-brown or darker when the spores mature. In maturity, the gills are free from attachment to the stipe, and are packed close together with little intervening spaced between them. The stipe is 7–20 cm long, and 1–2.5 cm thick but with a thicker or bulbous base. Firm, smooth, and lacking the scales found on the cap, the stipe is white but discolors dingy pinkish or brownish in age or after handling. The flesh in the extreme base usually stains pale yellowish when bruised. The partial veil is membranous, white, and forms a thick, felt-like ring on the upper portion of the stipe. The ring is skirtlike but often flares outward instead of collapsing against the stipe. A drop of dilute potassium hydroxide placed on the cap turns yellow.

Spore prints are purplish brown to chocolate brown. The smooth, thick-walled spores are broadly ellipsoidal, and typically measure 5.8–7.3 by 3.7–4.4 μm. The basidia are four-spored, club-shaped, hyaline are sac-shaped to club-shaped, hyaline to pale yellowish brown in color, and have dimensions of 18.3–25.6 by 7.3–11.0 μm; there are no cystidia on the gill face .
The Caps of Agaricus hondensis. Their pinkish hue is attractive and their size helps as well. The largest is close to 15cm across! https://www.jungledragon.com/image/86088/a_felt-ring_agaricus.html Agaricus hondensis,Canada,Fall,Felt-ringed Agaricus,Geotagged

Naming

Distinctive field characteristics of ''Agaricus hondensis'' include its woodland habitat, the yellow staining reaction with KOH, and its odor. ''Agaricus freirei'' closely resembles ''A. hondensis'', and, based on similarities in DNA sequences, is a close relative. ''A. freirei'' is found in coastal regions of Spain. ''A. hondensis'' has also been confused with ''A. silvaticus'' and ''A. placomyces''. ''A. sylvaticus'' does not have foul-smelling flesh, and has a negative KOH reaction. ''A. placomyces'' is found from the midwestern United States eastward. Another lookalike, the edible ''A. subrutilescens'', has similar overall coloration, but is distinguished from ''A. hondensis'' by a mild odor, a shaggy stipe, and a less substantial ring.

Distribution

A saprobic species, the fruit bodies of ''Agaricus hondensis'' grow scattered or in groups under conifers or in mixed forests. They have also been reported to grow in fairy rings. The fungus is found in the Pacific Coast of North America, from British Columbia in Canada south to California, but is most common in California. The mushroom fruits in the fall from September to October throughout much of its range, but in California the fruiting season tends to be from November to February.

Habitat

A saprobic species, the fruit bodies of ''Agaricus hondensis'' grow scattered or in groups under conifers or in mixed forests. They have also been reported to grow in fairy rings. The fungus is found in the Pacific Coast of North America, from British Columbia in Canada south to California, but is most common in California. The mushroom fruits in the fall from September to October throughout much of its range, but in California the fruiting season tends to be from November to February.

Defense

''Agaricus hondensis'' mushrooms are toxic, and consuming the fruit bodies causes gastroenteritis. Some fruit bodies smell of creosote, an odor that becomes even more prevalent if the mushrooms are cooked. Cooking also introduces an unpleasant soapy-metallic flavor. The fruit bodies are used as food by the vagrant shrew and the American shrew mole . Relatively high levels of the chemical hydroquinone are present in fruit bodies.

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Taxonomy
KingdomFungi
DivisionBasidiomycota
ClassAgaricomycetes
OrderAgaricales
FamilyAgaricaceae
GenusAgaricus
SpeciesA. hondensis
Photographed in
Canada