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Amanita mutabilis

[ Basidiomycota > Agaricales > Amanitaceae > Amanita . . . ]

by Michael Kuo

"The quick change of color when the stem is wounded is different from anything I have observed in Amanita," wrote the mycologist who first described Amanita mutabilis (Beardslee 1919). "The change is much quicker and much more distinct than in A. rubescens. Three minutes seemed to be the usual period for developing a deep carmine."

The prompt pink to purplish red bruising, the white cap and stem, and the way the volva forms a rimmed upper edge on the stem's bulb characterize this gorgeous species, which is distributed from Texas to Florida and New Jersey.

Thanks to Andy Methven for collecting, documenting, and facilitating study of Amanita mutabilis.


Ecology: Mycorrhizal with oaks and pines in pine-oak forests; summer and fall; fairly widely distributed from Texas to Florida and New Jersey. The illustrated and described collection is from Georgia.

Cap: 6–10 cm across; convex, expanding to broadly convex, planoconvex, or flat; bald; tacky when fresh; white, bruising pink; with one to several flat, whitish to faintly grayish patches; the margin not lined.

Gills: Free from the stem or nearly so; white; close; bruising pink; short-gills present.

Stem: 6–11 cm long; 1–2 cm thick; fairly equal above a swollen base (3–4 cm thick); dry; finely silky; white; bruising pink; with a white, fragile, skirtlike ring and a white volva that features a rimmed upper edge.

Flesh: White; quickly staining pink on exposure.

Odor: Not distinctive.

Microscopic Features: Spores 11–13.5 x 7–8 µm; ellipsoid; smooth; hyaline in KOH; amyloid. Basidia 4-sterigmate. Hymenial cystidia not found. Subhymenium inflated-ramose. Pileipellis a cutis of elements 2.5–7.5 µm wide, hyaline in KOH.

REFERENCES: Beardslee, 1919. (Tulloss, 1984; Weber & Smith, 1985; Jenkins, 1986; Metzler & Metzler, 1992; Tulloss, continuously updated.) Herb. Kuo 08272001 (portion of ASM 12461).

This site contains no information about the edibility or toxicity of mushrooms.


Amanita mutabilis

Amanita mutabilis

Amanita mutabilis

Amanita mutabilis

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Kuo, M. (2020, September). Amanita mutabilis. Retrieved from the MushroomExpert.Com Web site: