| Major Groups > Boletes > Boletus > Boletus pseudosensibilis |
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Boletus pseudosensibilis [ Basidiomycetes > Boletales > Boletaceae > Boletus . . . ] by Michael Kuo A number of species are very close in appearance to Boletus pseudosensibilis--all with reddish brown to brown caps, yellow flesh and pore surfaces that bruise blue, and non-reticulate yellowish stems with varying degrees of reddish colorations. Among these mushrooms, however, Boletus pseudosensibilis is the only one that displays a blue flash when a drop of ammonia is applied to the cap. Additionally, Boletus pseudosensibilis has somewhat shorter spores than most of its look-alikes, and it tends to have less red on the stem than some of the others. Boletus pseudosensibilis should not be eaten, since some of its close look-alikes are poisonous. Description: Ecology: Mycorrhizal with hardwoods, especially oaks; growing alone, scattered, or gregariously; summer and fall; widely distributed in eastern North America. Cap: 6-14 cm; convex, becoming broadly convex or almost flat; dry; smooth; in age becoming somewhat cracked, with yellow flesh showing through the cracks; reddish brown to yellowish brown; margin even. Pore Surface: Bright yellow; not bruising or bruising faintly when young--later bruising blue, then brown; 1-3 pores per mm at maturity; tubes 5-8 mm deep. Stem: 8-16 cm long; 1.5-3 cm thick; more or less equal, or enlarging to base; dry; solid; yellow overall, with reddish tinges toward the base; not reticulate. Flesh: Whitish to pale yellow in the cap; deep yellow or red in the stem; staining quickly blue on exposure. Odor and Taste: Not distinctive. Chemical Reactions: Cap flashing blue, then resolving to purplish gray with ammonia (see the movie linked to the right); flesh brownish to orange with KOH. Other reactions not recorded in the literature, but in my experience the cap is yellow to orange with KOH, the flesh is negative to faintly rusty grayish with ammonia, and iron salts produce a gray reaction on the cap, and a grayish olive reaction on the flesh. Spore Print: Olive brown. Microscopic Features: Spores 9-12 x 3-4 µ; smooth; spindle-shaped or nearly so. Pileipellis with short elements up to 20 µ wide. REFERENCES: Smith & Thiers, 1971. (Smith & Thiers, 1971; Smith, Smith & Weber, 1981; Phillips, 1991/2005; Both, 1993; Bessette, Roody & Bessette, 2000; Roody, 2003.) Herb. Kuo 07250304, 08210501, 08180601, 07300701. Further Online Information: Boletus pseudosensibilis in Smith & Thiers, 1971 |
Click the image below for a movie of the cap's reaction to ammonia.
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Cite this page as: Kuo, M. (2004, January). Boletus pseudosensibilis. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/boletus_pseudosensibilis.html |