Boletus speciosus

[ Basidiomycetes > Boletales > Boletaceae > Boletus . . . ]

by Michael Kuo

The rare Boletus speciosus is a gorgeous, reticulate version of the more common and better known Boletus bicolor. The red and yellow colors are offset nicely by the indigo blue bruising. Boletus pseudopeckii, also known as Boletus speciosus var. brunneus, is similar but less brightly colored; its rusty red cap soon fades to tan. A closer look-alike, Boletus peckii, has a bitter taste, but can only be reliably separated with a microscope (see below).

Boletus speciosus should not be eaten. While some field guides report it as edible, it is a blue-stainer that could easily be mistaken for a poisonous species.

Description:

Ecology: Mycorrhizal with hardwoods; growing alone or scattered, often in wet woodland areas; summer and fall; rare; widely distributed in eastern North America.

Cap: 6-15 cm; convex, becoming broadly convex; dry; smooth or very finely felty; bright red to rose pink, sometimes with mottled areas of yellow.

Pore Surface: Bright yellow, becoming olive yellow, sometimes developing reddish colorations with old age; bruising promptly blue; 2 pores per mm at maturity; tubes to about 1.5 cm deep.

Stem: 5-13 cm long; 1.5-4 cm thick; equal or with a swollen base; dry; solid; yellow above, reddish below; reticulate over the top half or overall; bruising promptly blue.

Flesh: Pale yellow; often chrome yellow in the stem base; staining quickly blue on exposure.

Odor and Taste: Not distinctive.

Chemical Reactions: KOH orange on cap surface; pale orange on flesh. Ammonia negative to yellowish on cap; erasing blued areas on flesh. Iron salts grayish on cap; negative on flesh.

Spore Print: Olive brown.

Microscopic Features: Spores 11-15 x 3-4 µ; smooth; subfusiform. Pileipellis a cutis.

REFERENCES: Frost, 1874. (Coker & Beers, 1943; Snell & Dick, 1970; Smith & Thiers, 1971; Smith, Smith & Weber, 1981; Phillips, 1991/2005; Both, 1993; Bessette, Roody & Bessette, 2000.) Herb. Kuo 07170403.

The similar Boletus peckii has a bitter taste, according to most authors. It has spores 9-12 µ long, and a pileipellis arranged as a perpendicular trichoderm.

Further Online Information:

Boletus speciosus in Smith & Thiers, 1971
Boletus speciosus at Roger's Mushrooms

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Cite this page as:

Kuo, M. (2005, March). Boletus speciosus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/boletus_speciosus.html