Tylopilus alboater

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

by Michael Kuo

This easy-to-recognize Tylopilus has a blackish, velvety cap and a dark, smooth stem. Its pore surface is initially white; later it becomes pinkish and bruises promptly red, then black. It has a mild taste, unlike the many bitter Tylopilus species, and its flesh turns pink, then slowly grayish on exposure to air. It is mycorrhizal with hardwoods in eastern North America.

Tylopilus alboater is a good edible mushroom. Like most boletes, it is better when dried and reconstituted.

Description:

Ecology: Mycorrhizal with hardwoods (especially oaks); growing alone or scattered; summer and fall; widely distributed east of the Rocky Mountains.

Cap: 3-15 cm; convex, becoming broadly convex or flat; dry; velvety; sometimes with a white dusting when young; black or dark grayish brown; in my experience, often darkening on handling.

Pore Surface: Whitish becoming pinkish; bruising red, then brown to black; pores angular, 2 per mm; tubes to 1 cm deep.

Stem: 4-10 cm long; 2-4 cm thick; more or less equal, or enlarging towards base; colored like the cap or paler; sometimes with a white dusting; fairly smooth; not reticulate or merely finely so near the apex; in my experience, often darkening on handling.

Flesh: Thick and white; discoloring pinkish on exposure to air, then turning slowly grayish; black in the stem base.

Odor and Taste: Not distinctive.

Chemical Reactions: Flesh greenish to bluish with iron salts; pinkish orange with KOH; olive, then brownish orange with ammonia. Cap orangish with KOH; negative with iron salts or ammonia.

Spore Print: Pink.

Microscopic Features: Spores 7-11 x 3.5-5 µ oval or elliptical to spindle-shaped; smooth.

REFERENCES: (Schweinitz, 1822) Murrill, 1909. (Saccardo, 1888; Coker & Beers, 1943; Snell & Dick, 1970; Smith & Thiers, 1971; Smith, Smith & Weber, 1981; Weber & Smith, 1985; Phillips, 1991/2005; Lincoff, 1992; Both, 1993; Bessette, Roody & Bessette, 2000; Roody, 2003; Miller & Miller, 2006; Kuo, 2007.) Herb. Kuo 07230308, 09300301, 07160702.

Further Online Information:

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

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Cite this page as:

Kuo, M. (2003, September). Tylopilus alboater. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/tylopilus_alboater.html