Tylopilus sordidus

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

by Michael Kuo

Tylopilus sordidus is a blue-staining, dark-capped bolete with a white pore surface that becomes brownish with maturity. It is part of a group of species that are currently placed in Tylopilus by most mycologists (though some give the group its own genus name, Porphyrellus)--but which will now probably have to be placed somewhere else, if I am reading DNA studies on boletes correctly (see Binder & Hibbett, 2004 for an example).

Although several species in the Porphyrellus group have been named on the basis of minor differences in physical features, the wisest course for the time being is probably to view the species lines as tentative. What I am calling Tylopilus sordidus here encompasses several official taxa, all of which have whitish young pore surfaces--as opposed to the brown young pore surface of Tylopilus porphyrosporus, which is also a bit stockier.

Though it is probably not poisonous, edibility is not reliably documented for Tylopilus sordidus. Do not experiment.

Description:

Ecology: Mycorrhizal with hardwoods and conifers; growing alone or scattered; often found in disturbed-ground settings like roadsides, ditches, and so on; summer and fall; probably widely distributed east of the Rocky Mountains.

Cap: 2-5 cm; convex, becoming broadly convex or nearly flat in age; dry; finely velvety when young, typically cracking and splitting with maturity, exposing whitish flesh that may stain pinkish or bluish; dark brown to grayish, often with bluish tints by maturity, at least near the margin.

Pore Surface: Whitish to yellowish at first, becoming brown to reddish brown; bruising blue, then reddish brown; pores circular, 1-2 per mm; tubes to 1 cm deep.

Stem: 4-8 cm long; up to 1 cm thick; more or less equal; colored like the cap; not reticulate.

Flesh: White; staining pinkish and/or blue when sliced.

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

Chemical Reactions: Ammonia dark purple to black on cap; yellowish to orangish on flesh. KOH pinkish, orangish, reddish, or negative on cap and flesh. Iron salts negative on cap; bluish to grenish or negative on flesh.

Spore Print: Brown to reddish brown or purplish brown.

Microscopic Features: Spores 10-17 x 4-8 µ; subfusoid to elliptical; smooth. Cystidia to about 75 x 20 µ; mostly fusoid-ventricose; contents often coagulated or grainy.

I am treating Tylopilus cyaneotinctus and Tylopilus fumosipes as probable synonyms.

REFERENCES: (Frost, 1874) Smith & Thiers, 1968. (Frost, 1874; Saccardo, 1888; Coker & Beers, 1943; Smith & Thiers, 1968; Snell & Dick, 1970; Smith & Thiers, 1971; Grund & Harrison, 1976; Wolfe, 1979; Smith, Smith & Weber, 1981; Phillips, 1991/2005; Both, 1993; Bessette, Roody & Bessette, 2000; McNeil, 2006.) Herb. Kuo 07230401, 07070701.

Further Online information:

Tylopilus sordidus in Smith & Thiers, 1971
Tylopilus cyaneotinctus in Smith & Thiers, 1971
Tylopilus sordidus at Roger's Mushrooms

Frost's original description of Boletus sordidus (1874):

"Pileus pulvinate, dark dirty brown, subtomentose, about 2 inches broad. Tubes at first white, long, not quite adnate, turning bluish green. Stem brownish, streaked very dark, smaller as it enters the pileus, generally green around the part not adnate. Flesh white, now and then tinged with green. Spores .0126-.0052 m.m."

"On recent excavations in woods. July."

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Cite this page as:

Kuo, M. (2007, December). Tylopilus sordidus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/tylopilus_sordidus.html