Phylum:Basidiomycota >> Class: Basidiomycetes >>  Order: Boletales 
 BCRC Number NO BCRC Number!  
 Scientific Name: Xerocomus castanellus

Xerocomus squarrosoides (Snell & Dick) Sing., Farlowia 2: 295. 1945.

Xerocomus castanellus (Pk.) Snell & Dick, Mycologia 50: 57. 1958.

Boletinus squarrosoides Snell & Dick, Mycologia 28: 468. 1936.

Basionym:Boletinus castanellus Peck, Bull. Torr. Bot. Club 27: 613. 1900.

 Description: Pileus 3-7 cm broad, plano-convex and depressed, surface tomentose to fibrillose, color scarlet, dark chestnut to pale yellowish brown, sometimes adorned with minute erect or re-supinate dark-colored fibrillose scales. Context whitish or yellowish, changing to pale chocolate-brown. Tubes 4-6 mm long, adnato-decurrent with the tubes appearing like gills near the stipe, olive-brown, changing to blue when cut. Pores 2-3 mm broad, angular and compound, radiately arranged, concolorous with the tubes, changing to blue when bruised. Stipe 3-7 cm long, 5-10 mm broad, subequal, surface subpruinose or minutely furfuraceous, not reticulate but striate at apex, concolorous with pileus, sometimes yellowish at apex but reddish at base, changing to red when handling. Spore print pale ochraceous brown or pale yellowish brown. Spores 13.5-14 × 5.5-6 μm, ellipsoid to somewhat ovoid. Basidia 43-58 × 14-15 μm, four sterigmata , 3-4 μm long. Pleurocystidia 68-98 × 13-15.5 μm, clavate, fusi-form to ventricose-rostrate, hyaline to yellow.

Taiwan, Taichung: Tiehpilunhsi, 30 Sept. 1994, Huang HW. 855. Yunlin: Shihpin, 16 May 1996, Huang HW. 1582.

 Habitat: Solitary under broad-leaved or bamboo forest.

Taiwan, China (Sichuan), North America.


Snell, WH and Dick, EA. 1958; Chen, CM et al. 1997.


C. M. Chen

 Note: In 1936, Snell and Dick designated a new species Boletinus squarrosoides, “apparently nearest to B. castanellus” but distinct in its larger size, more decurrent tubes, more tufted-tomentose cap and perhaps somewhat in color of tubes and stem. Coker and Beers (1943) had suggested it should be treated as only a variety of the latter. Singer (1945) suggested B. squarrosoides to its synonym (B. castanellus). Eventually Snell and Dick (1958) accepted Singer,s judgement and christened it to Xerocomus castanellus. From the macroscopic features view, the nomenclature of the species are complicated as above. In our two specimens collected from various places, the pileus and stem are not completely similar in either of the two. However, the microscopic features individually match with the original descriptions of Boletinus castanellus and Xerocomus squarrosoides, so we take the two specimens to be X. castanellus.