Phylum:Basidiomycota >> Class: Basidiomycetes >>  Order: Boletales 
 BCRC Number NO BCRC Number!  
 Scientific Name: Boletellus russellii

Boletellus russellii (Frost) Gilbert, Les Bolets, p. 107. 1931.

Basionym: Boletus russellii Frost, Bull. Buff. Soc. Nat. Sci. 2:104. 1874.

 Description: Pileus 3-9 cm broad, hemispheric to convex with a strongly incurved margin, expanding to broadly convex with age; surface dry, subtomentose to tomentose, sometimes squamulose, becoming areolate; margin sterile, entire, incurved when young; color brown to brownish yellow, sometimes olive gray. Context up to 1.7 cm thick, whitish to pallid-yellow, becoming eventually melleous in the base of the stipe, and reddish under the cuticle, almost unchanging when cut. Tubes up to 1 cm long, depressed around the stipe, often extending for short distances down the stipe as lines, yellow to olive green, changing to dark blue when bruised. Pores up to 2 mm wide, angular, narrower in the marginal row, at first 0.3 mm wide, then becoming wider, most frequently 0.8-1 mm in diameter. Stipes 7-12 cm long, 0.9-1.6 cm broad, equal or expanding toward base, solid, flesh yellow, surface covered overall with coarse ridge-like reticulations, color brownish red or dull brick red, viscid at base, unchanging when cut. Spore print dark olive to near sepia. Spores 16-18 × 7-9 μm, in face view ellipsoid with a suprahilar depression, in profile view obscurely inequilateral, with 16-18 longitudinal striate and grooved in outer wall, bister in KOH. Basidia 40-53 × 14-18 μm, clavate, thin-walled, hyaline in KOH, pale yellow in Melzer's. Pleurooystidia 75-85 × 12-20 μm, mostly fusoid-ventricose, the apical half often elongation and the apex subacute, thin-walled, hyaline in KOH, pale yellow in Melzer's. Hymenophoral trama divergent. Clamp connection absent.

Taiwan, Nantou: Sun Moon Lake, alt. 850 m, 23 Aug 1994, Chen CM 722.

 Habitat: Solitary to scattered under Myrsine sequinii Levl.

Taiwan, China (Anhwei, Yunnan), Japan, North America.


Chen, CM et al. 1998.


C. M. Chen

 Note: This species can be easily be confused with Boletellus jalapensis (Murr.) Gilbert, which differs the former by having smooth, glabrous stipe( Murrill,1910). It similar to that of Boletellus ananas (Curt.) Murrill has a longitudinally winged or ribbed ornamentation. Its exosporial wall is brown with longitudinal, wing-like, lamellose ridges which run from the apical pole to the hilar tube, suddenly stopping at the apex. Occasionally some of the ridges are connected by a few scattered anastomosing ridges. The number of longitudinal ridges are about 16-18 at the poles, and which project 1.3-2.1 μm (Fig.14). But the latter lacks cross connections between the longitudinal ornamentations, besides apex is smooth and rounded (Fig.15).