Phylum:Basidiomycota >> Class: Basidiomycetes >>  Order: Boletales 
 BCRC Number NO BCRC Number!  
 Scientific Name: Austroboletus gracilis

Austroboletus gracilis (Peck) Wolfe, Bibl. Mycol. 69: 69. 1979.

Basionym: Boletus gracilis Peck., Rep. N. Y. St. Mus. 24: 78. 1872.

 Description: Pileus 3-5 cm broad, convex to hemispheric, surface smooth to minutely tomentose and finely areolate, color chesnut brown or paler. Context soft, whitish and slightly pink, color unchanging when bruised, slightly bitter in taste. Tubes 0.7-1.5 cm long, strongly depressed around stipe, whitish , becoming brown pink to vinaceous. Pores circular to angular, 0.5-1.5 mm broad, whitish to silvery vinaceous. Stipe 5-12 cm long, 7-10 mm broad, slender tapered toward apex, quite bulbous at base up to 1.5-3.0 cm thick, solid, often bent, surface finely pruinose velvety, granular in appearance and often conspicuously striate, the striae sometimes anastomosing, concolorous with pileus or paler , with whitish mycelium around base. Spore print rosy brown. Spores 7-9.5 × 6.5-8.5 μm , fusiform-elliptical, with finely punctate in face view. Basidia 42-48 × 14-15 μm, clavate, sterigmata 2-4, 6-8 um long, Pleurocystidia 44-64 × 8-18 μm , clavate, hyaline and thin-walled. Tube trama of phylloporoid type.

Taiwan, Taichung: Pahsienshan, alt. 1150m, 22 Jun 1995, Huang HW. 1236.

 Habitat: Solitary under conifers and broad-leaved forest, apparently growing with Quercus, Pinus, Tsuga, Betula etc.

Taiwan, China (Yunnan, Tibet), Japan, New Guinea.


Corner, EJH. 1972; Wolfe, JCB. 1979; Chen, CM et al. 1997.


C. M. Chen

 Note: Wolf (1979) based on the result of EM scanning observation, proposed genus Austroboletus. Its fruit-bodies have a well developed marginal veil, a long lacunose-reticulate stem and boletoid tube-trama. Its spores are vinaceous pink to purple brown or chocolate in the mass; they are fusiform-amygdaloid and show a certain amount of compression. They have a hyaline exospore and coloured endospore with conical warts or a close reticulation, apiculus 0.3-0.5 μm long. Corner (1972) had explained the smooth boleloid spore has evolved from the ornamented and Austroboletus is a transition between the twos. The spores of A. gracilis almost entirely ornamented but with smooth adaxial patch. There is a reasonable proof for Corner's suggestion here.