|Major Groups > Boletes > Boletus > Boletus spadiceus var. gracilis|
Boletus spadiceus var. gracilis
by Michael Kuo
Although this little bolete is currently classified as a diminutive "variety" of Boletus spadiceus, I will side with boletologist Ernst Both (1993), who believes it "probably deserves specific rank." Yes, it has a brownish cap that flashes green when a drop of ammonia is applied--and yes, its overall colors are similar to Boletus spadiceus. But its stature is completely different from that of the fairly stocky type variety and, more importantly, it is a mycorrhizal partner with hardwoods in eastern North America rather than associating with conifers in northern and montane areas.
Ecology: Mycorrhizal with hardwoods; growing alone, scattered, or gregariously; summer and fall; widely distributed from the Great Plains eastward.
Cap: 2-8 cm; convex, becoming broadly convex or almost flat; dry; finely velvety; yellowish brown to dull brown or reddish brown.
Pore Surface: Yellow, becoming olive yellow; sometimes bruising reddish brown; pores angular, especially near the stem, 1-2 mm wide; tubes to about 1.5 cm deep.
Flesh: Whitish in the cap; yellow in the stem; not staining on exposure, or staining faintly bluish.
Odor and Taste: Pleasant; not distinctive.
Chemical Reactions: Ammonia flashing green to blue-green on cap surface, then resolving to reddish brown; flashing greenish on flesh, then resolving to negative. KOH purple on cap surface; orangish on flesh. Iron salts olive on cap surface; olive on flesh.
Spore Print: Olive brown.
Microscopic Features: Spores 9-13 x 3.5-4.5 µ; smooth; subfusiform; yellow in KOH. Hymenial trama amyloid when first mounted. Hymenial cystidia fusoid-ventricose to fusoid; hyaline in KOH; to about
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Cite this page as:
Kuo, M. (2007, December). Boletus spadiceus var. gracilis. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/boletus_spadiceus_gracilis.html