Phylum:Basidiomycota >> Class: Basidiomycetes >>  Order: Boletales 
 BCRC Number NO BCRC Number!  
 Scientific Name: Boletus speciosus

Boletus speciosus Frost, Bull. Buff. Soc. Nat. Sci. 2: 101. 1874.

 Description: Pileus 7-12 cm broad, hemispheric to broadly convex, margin incurved and even, surface dry, inherently felted, rose-pink to vinaceous russet with some yellowish areas at maturity, context 10-16 mm thick, moderately firm, pale yellow, quickly turning blue when cut. Tubes 6-10 mm deep, adnate but varying to slightly depressed, with decurrent reticulations on the stipe, bright yellow, turning immediately blue then darker blue-brown when bruised. Pores 0.3-0.5 mm broad, lightly stuffed when young, often dull reddish at maturity. Stipe 4-10 cm long, 1.5-3 cm thick, equal to clavate, some pinched at very base, solid, bright yellow toward the base, becoming paler toward the apex, reddish at base and in damaged area, surface finely reticulated over upper half or overall, context quickly turning blue but in the base often chrome-yellow when cut. Spore print olive-brown. Spores 11-15 × 3-4 μm, smooth, narrowly oblong to subfusoid with subacute ends in face view, narrowly inequilateral to subcylindric in profile view, pale ochraceous in KOH solution, yellow to pale tawny in Melzer's reagent. Basidia 24-27 × 8-9 μm, clavate, sterigmata two or four, 7-9 μm long, yellow in KOH solution or Melzer's reagent. Pleurocystidia 33-45 × 8-12 μm, narrowly ventricose to fusoid with subacute apex, walls sometimes flexuous, hyaline to yellowish in KOH solution or Melzer's reagent. Tube trama divergent and gelatinous, the hyphae hyaline, thin-walled and smooth with some dextrinoid debris along the hymenium. Pileus cuticle matted down into a layer of interwoven hyphae, hyphae 3-5 μm wide, the hyphae cells tubular, the end-cells tubular and obtuse.

Taiwan, Nantou: Shanlinhsi, alt. 1750m, 5 Nov 1997, Chen CM 1980.

 Habitat: Scattered under broad-leaved forest.

Taiwan, China, Japan, North America, Europe.


Chen, CM et al. 1998.


C. M. Chen

 Note: This species is apparently most closely related to B. regius Krombholz, but the former has widerspores, a more elongated stipe, and the flesh turns blue immediately when exposed. In our collections the specimens described agree with the lectotype designated by Smith and Thiers in having identical narrow, cylindrical spores, a pileus cutis of appressed hyphae 3-5 μm wide, in staining blue when injured, and in having rose tints lower down on the stipe.