Amanita farinosa

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by Michael Kuo

Here is a small, ringless Amanita species that is fairly easily distinguished from the ringless species centered around Amanita vaginata, since it lacks a sacklike volva, and features a cap and stem that are covered with fine, mealy powder. The powder is likely to wear away in maturity, or during the process of picking the mushrooms and bringing them home, but it will be present on young, fresh specimens. Even without the powder, however, the species is fairly unmistakable on the basis of its relatively small size, its dirty brown colors, its lack of a ring or volva, and its slightly bulbous stem base.

Description:

Ecology: Mycorrhizal with hardwoods or conifers; sometimes in grassy areas; early spring to late fall; east of the Rocky Mountains, from Quebec to Costa Rica--though a similar western species is probably undescribed (see comments below).

Cap: 2.5-6.5 cm; ovalish at first, becoming convex or nearly flat, sometimes with a shallow central depression; dry; the surface dusted with fine, mealy powder which rubs off easily; occasionally with the powder gathered into a few scattered warts or patches; the margin lined; brownish gray to brownish.

Gills: Free from the stem or slightly attached to it; whitish; close; not bruising.

Stem: 3-6.5 cm long; .3-1 cm thick; more or less equal; usually with a slight basal bulb; covered with powder like the cap; white to dirty; without a ring; typically with a slight band of dense powder at the rim of the bulb, but without a sacklike volva; solid or partially hollow in age.

Flesh: White; not staining on exposure.

Odor: "[S]trong, mink smell in old specimens" (Phillips). Have you ever smelled a mink?

Spore Print: White.

Microscopic Features: Spores 5.5-8 x 6-8 µ; smooth; round to broadly elliptical; inamyloid.

REFERENCES: Schweinitz, 1822. (Jenkins, 1977; Smith, Smith & Weber, 1979; Thiers, 1982; Weber & Smith, 1985; Jenkins, 1986; Phillips, 1991/2005; Lincoff, 1992; Barron, 1999; Roody, 2003; Tulloss, 2003; McNeil, 2006; Miller & Miller, 2006.) Herb. Kuo 06180402, 07100701.

Tulloss (2003) reports that the name Amanita farinosa "is applied to a taxon of western North America [that] may be a distinct species." I suspect that this western impostor is the "Amanita farinosa" described by Smith, Smith & Weber (1979, p. 163) as occurring "under spruce, along the Pacific Coast, late fall." The stem of this mushroom is wider ("1-1.5 cm"); in addition Smith reports a "pale gray" cap color and amyloid spores 7-9 x 5-6 µ.

Further Online Information:

Amanita farinosa at Tulloss's Studies in Amanita
Amanita farinosa at Roger's Mushrooms

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Cite this page as:

Kuo, M. (2008, March). Amanita farinosa. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/amanita_farinosa.html