Major Groups > Boletes > Tylopilus > Tylopilus ballouii


Tylopilus ballouii

[ Basidiomycetes > Boletales > Boletaceae > Tylopilus . . . ]

by Michael Kuo

This Tylopilus is unmistakable when fresh. Its bright reddish orange colors are reminiscent of Stropharia aurantiaca, and its brown-bruising pore surface is whitish. However, the bright colors soon begin to fade, and eventually Tylopilus ballouii becomes yet another boring, tan bolete. What is it with the pigments in Tylopilus? The purple shades in Tylopilus rubrobrunneus and Tylopilus plumbeoviolaceus are also short-lived, and the genus seems bent on demonstrating that the splendors of youth fade into boring, monotonous conformity. However, middle-aged mushroomers should be encouraged by the fact that other mushrooms, like Pluteus aurantiorugosus, hold their colors well into old age.


Ecology: Mycorrhizal with hardwoods, especially oaks and Beech, but occasionally reported with pines; growing alone, scattered, or gregariously; summer and fall; primarily southeastern in distribution but reported from as far north as New York and Massachusetts.

Cap: 5-12 cm; convex, becoming broadly convex or nearly flat in age; dry; fairly smooth or finely velvety; bright reddish orange when young, soon fading to reddish brown, cinnamon brown, or tan.

Pore Surface: Creamy whitish; bruising brown; eventually brownish; pores circular, 1-2 per mm; tubes to 1 cm deep.

Stem: 2.5-12 cm long; up to 2.5 cm thick; equal or with a swollen base; dry; smooth or finely reticulate near the apex; orangish when young, but soon pale orange, yellowish, or whitish.

Flesh: White; soft.

Odor and Taste: Taste mild or slightly bitter; odor not distinctive.

Chemical Reactions: Ammonia yellow on cap; negative on flesh. KOH yellow on cap and flesh. Iron salts olive gray on cap; bluish gray on flesh.

Spore Print: Pale brown to reddish brown or purplish brown.

Microscopic Features: Spores 8-10 x 4-5 µ; ovoid to elliptical; smooth. Pileipellis a cutis of cylindric elements 3-7 µ wide, with rounded to subacute apices; sometimes partially gelatinized; yellow to orange in KOH.

REFERENCES: (Peck) Singer, 1947. (Singer, 1947; Snell & Dick, 1970; Smith, Smith & Weber, 1981; Weber & Smith, 1985; Phillips, 1991/2005; Lincoff, 1992; Metzler & Metzler, 1992; Both, 1993; Bessette, Roody & Bessette, 2000; Miller & Miller, 2006; Kuo, 2007; Ortiz-Santana et al., 2007.)

The Index Fungorum reports Rubinoboletus ballouii as the current name for this taxon, citing a 1983 publication by Heinemann & Rammeloo in Bulletin du Jardin Botanique National de Belgique (the "Bulletin of the National Botanic Garden of Belgium," which I doubt we will find on newsstands everywhere). I will put my library's interlibrary loan service to the test, as well as my French, and report back.

    Note, December 2008: Props to my university's interlibrary loan service, which handily produced the text in question. However, Heinemann & Rammeloo combine Tylopilus ballouii into Rubinoboletus without comment, so I've made little progress. DNA results from Binder & Hibbett (2004 place Rubinoboletus ballouii far from the core group of Tylopilus taxa (and the type species of the genus, Tylopilus felleus) . . . so perhaps something besides Tylopilus is the best choice. A recent paper by Halling, Osmundson & Neves (2008) presents preliminary DNA evidence suggesting that "T. ballouii as currently circumscribed represents a species complex rather than a single species."

Further Online information:

Tylopilus ballouii at Macrofungi of Costa Rica
Tylopilus ballouii at Roger's Mushrooms


Tylopilus ballouii

Tylopilus ballouii

Tylopilus ballouii

Tylopilus ballouii

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Kuo, M. (2008, November). Tylopilus ballouii. Retrieved from the MushroomExpert.Com Web site: