Phylum:Basidiomycota >> Class: Basidiomycetes >>  Order: Boletales 
 BCRC Number NO BCRC Number!  
 Scientific Name: Xanthoconium affine

Basionym: Boletus affine Peck, Ann. Rept. N. Y. State Mus. 25: 81. 1873.

Xanthoconium affine (Peck) Singer, Amer. Midl. Nat. 37: 88. 1947.

 Description: Pileus 3-7 cm broad, convex to plane, sometimes centrally depressed, surface subtomentose and rugulose, dry, subviscid when wet, margin entire, becoming rimose in age, color of various shades of dull yellow brown to light cinnamon brown, context white, unchanging when cut. Tubes 5-9mm long, depressed at stipe, color ochraceous. Pores 1-3 mm broad, circular or angular, concolorous with tube, staining yellowish slightly when injured. Stipe 3.5- 6.5 cm long, 0.6-1.1 cm thick, slightly enlarged downward, but pointed at base, solid, surface with low longitudinal ridges, color pallid and pruinose at apex, base white, context white and unchanging when cut.Spore print ochraceous buff. Spores 13-15 × 5.5-6 μm, oblong in face view, narrowly inequilateral in profile, smooth, pale dingy yellow in KOH solution. Basidia 45-52 × 13-15 μm, subclavate, hyaline in KOH solution, sterigmata four, 5-6 μm long.Pleurocystidia 53- 75 × 12-15 μm, fusoid-ventricose or sometimes lageniform, thin-walled, hyaline in KOH solution. Tube trama parallel to obscurely divergent, sub gelatinous. Pileal cuticle an epithelium, the end cells cystidioid and clavate to ventricose, 30-70 × 15-20 μm, brown in KOH solution. Clamp connections absent.

Taiwan, Nantou: Shanlinhsi, alt. 1750m, 8 Jun 1994, Chen CM 410.

 Habitat: Solitary under broad-leaved forest.

Taiwan, China, Japan, North America.


Smith, AH and Thiers, HD. 1971; Chen, CM et al. 1998.


C. M. Chen

 Note: This bolete is distinguished by the stipe with longitudinal ridges and spores with pale golden yellow tints in KOH solution. Microscopically, the specimen has larger basidia and pleurocystidia than those of Michigan; however, it do degree with the Peck type as reported by Smith & Thiers (1971). This species is common in the south province of China but being rare in the middle area of Taiwan, in spite of its favorite habitat of hardwood everywhere found.