Amanita flavorubescens

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by Michael Kuo

Here is a beautiful species of Amanita, fairly easily distinguished by its yellow cap, its yellow warts and fragile yellow volva, and its tendency to discolor reddish to reddish brown, especially in the stem. Amanita rubescens is very similar, but its cap is not yellow beneath the warts--and the warts themselves fade quickly to buff or pale tan.

The North American "blushers" are imperfectly described, and one often finds specimens that seem to intergrade between officially described taxa. For help sorting out the blushing amanitas of the world, see amanita expert Rod Tulloss's Key to Rubescent Species.

Field guides list edibility for this mushroom as "unknown," or "possibly poisonous." Even if it were listed as "edible," however, it should never be collected for the table, since it belongs to the genus containing the most deadly mushrooms on the planet. See my comments on Amanita Bravado for more thoughts on this topic.

Description:

Ecology: Mycorrhizal with hardwoods, especially oaks; occasionally in urban habitats when trees are near; spring through fall; fairly widely distributed east of the Rocky Mountains, but also known from Arizona and central Mexico.

Cap: 5-14 cm; oval, becoming convex or nearly flat; sticky at first or when wet; yellow to yellow-brown; adorned with yellow warts; margin lined or not lined.

Gills: Free from the stem or slightly attached to it; white; close.

Stem: 6-12 cm long; 1-2 cm thick; more or less equal; usually with a slightly swollen base; smooth or somewhat shaggy below the ring; the ring persistent, skirtlike, and white--sometimes with yellow stains at the edges; base with a yellow volva that breaks up and becomes indistinct, leaving yellow remnants on the soil.

Flesh: White throughout; soft.

Spore Print: White.

Microscopic Features: Spores 8-10 x 5-6 µ; smooth; elliptical; amyloid.

Amanita flavorubens is a synonym, according to some authors.

REFERENCES: Atkinson, 1900. (Saccardo, 1905; Kauffman, 1918; Smith, 1949; Smith, Smith & Weber, 1979; Weber & Smith, 1985; Arora, 1986; Jenkins, 1986; Phillips, 1991/2005; Lincoff, 1992; Roody, 2003; McNeil, 2006.) Herb. Kuo 06239507, 08300210, 05280703.

Further Online Information:

Amanita flavorubens at Tulloss's Studies in Amanita
Amanita flavorubescens at Roger's Mushrooms

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Cite this page as:

Kuo, M. (2002, September). Amanita flavorubescens. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/amanita_flavorubescens.html