Boletus vermiculosoides

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

by Michael Kuo

This is one of several similar hardwood-associated, eastern species in the Boletus vermiculosus species cluster, all of which have very dark red pore surfaces when in the button stage. Within the group, Boletus vermiculosoides can be recognized by its cap color, which is yellow when young--and by its comparatively small spores.

Description:

Ecology: Mycorrhizal with oaks; growing alone, scattered, or gregariously; summer and fall; eastern North America.

Cap: 4-12 cm; convex, becoming broadly convex or almost flat; dry; dull; smooth; yellow when in the button stage, but soon becoming brown; the margin often with a sterile overhanging extension.

Pore Surface: Dark red-brown, aging to orangish brown; bruising promptly blue; pores round, 2-3 per mm; tubes to about 1 cm deep.

Stem: 4-9 cm long; 1-2 cm thick; more or less equal; solid; whitish, yellowish, or with olive shades; often with brown fibers; bruising blue on handling; not reticulate.

Flesh: Yellow; staining blue on exposure.

Odor and Taste: Not distinctive.

Chemical Reactions: Ammonia red on cap surface; erasing blued areas of the flesh to yellowish or orangish. KOH dark red on cap surface; orange on flesh. Iron salts greenish to negative on cap surface; yellowish to negative on flesh.

Spore Print: Olive brown.

Microscopic Features: Spores 9-12 x 3-3.5 µ; smooth; subfusiform; yellowish in KOH. Hymenial cystidia mostly fusoid-ventricose; yellow in KOH; to about 60 x 12 µ. Pileipellis a cutis of cylindric hyphae 2.5-5 µ wide.

REFERENCES: Smith & Thiers, 1971. (Smith & Thiers, 1971; Smith, Smith & Weber, 1981; Bessette, Roody & Bessette, 2000; Roody, 2003; Binion et al., 2008.) Herb. Kuo 07039702, 07110703.

Further Online Information:

Boletus vermiculosoides in Smith & Thiers, 1971

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Cite this page as:

Kuo, M. (2007, December). Boletus vermiculosoides. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/boletus_vermiculosoides.html