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Agaricus subrutilescens

[ Basidiomycetes > Agaricales > Agaricaceae > Agaricus . . . ]

Taxonomy in Transition: ...  > Agaricales > Lepiotoid Clade (J&V, 1998)

by Michael Kuo

Agaricus subrutilescens is fairly easily recognized by the brown or wine colored fibers on its cap, its shaggy stem, and its distribution in forest ecosystems of the Pacific Northwest and northern California. Its flesh does not change color when sliced, and it has a pleasant, fruity odor. It is one of only two described Agaricus species whose caps turn green with the application of KOH--though this test is probably not needed to identify Agaricus subrutilescens successfully.


Ecology: Saprobic; growing alone, scattered, or gregariously in forest ecosystems under conifers and sometimes under hardwoods; fall and winter; northern California and the Pacific Northwest.

Cap: 5-20 cm; narrowly convex at first, becoming broadly convex, broadly bell-shaped, or nearly flat; dry; covered with brown to reddish brown or purple-brown, pressed-down fibers that sometimes become aggregated into small scales with maturity.

Gills: Free from the stem; close; whitish, then pink, then dark chocolate brown to blackish in maturity; covered when in the button stage with a whitish partial veil.

Stem: 5-20 cm long; up to 4 cm thick but usually 1-2 cm thick; more or less equal; with a thin, skirtlike, whitish ring; whitish; covered with soft shagginess below the ring, at least when young.

Flesh: White; not changing when sliced.

Odor and Taste: Odor sweet and fruity; taste similar.

Chemical Reactions: Cap surface slowly greenish with KOH.

Spore Print: Dark chocolate brown.

Microscopic Features: Spores: 4-6.5 x 3-4 µ; elliptical. Cheilocystidia up to 40 x 17 µ; clavate to nearly globose; scattered.

REFERENCES: (Kauffman, 1925) Hotson & Stuntz, 1938. (Hotson & Stuntz, 1938; Smith, 1940; Smith, 1975; Smith, Smith & Weber, 1979; Arora, 1986; Kerrigan, 1986; Phillips, 1991/2005; Lincoff, 1992; Miller & Miller, 2006.)

Further Online Information:

Agaricus subrutilescens at MykoWeb
Agaricus subrutilescens at Roger's Mushrooms


Agaricus subrutilescens

Agaricus subrutilescens

Agaricus subrutilescens

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Cite this page as:

Kuo, M. (2007, October). Agaricus subrutilescens. Retrieved from the MushroomExpert.Com Web site: